Pathology Answer key

Unit 1:
1. Describe in detail cellular adaptations?

Cellular adaptations are essential processes that enable cells to cope with changes in their
environment and maintain homeostasis. These adaptations can be responses to various
stimuli, such as changes in nutrient availability, oxygen levels, stress, or injury. Here’s a
detailed look at the different types of cellular adaptations:

1. Hypertrophy

Definition: Hypertrophy refers to the increase in cell size and functional capacity.

Mechanism: This adaptation occurs when cells are exposed to increased workload or stress.
For instance, in muscle cells, hypertrophy is a common response to regular exercise or
resistance training. The increase in cell size results from the synthesis of more structural
proteins and organelles.

Example: In cardiac muscle cells, hypertrophy can occur in response to increased pressure
overload, such as in cases of hypertension. This can initially help the heart pump more
effectively but may eventually lead to pathological conditions if the stress continues.

Consequences: While hypertrophy can be a normal physiological response, excessive

hypertrophy can lead to complications. For example, pathological hypertrophy in cardiac
cells can lead to heart failure.

2. Hyperplasia

Definition: Hyperplasia is the increase in the number of cells within a tissue or organ.

Mechanism: This adaptation occurs through cell proliferation, often in response to stimuli
such as hormonal signals or tissue injury. For instance, during the menstrual cycle, the
endometrium undergoes hyperplasia to prepare for potential implantation.

Example: In the liver, hyperplasia can occur following partial hepatectomy, where the
remaining liver cells proliferate to restore the organ’s mass.

Consequences: Hyperplasia can be physiological or pathological. Physiological hyperplasia

is normal and often reversible, while pathological hyperplasia, such as in certain types of
cancer, may lead to tumor formation and requires medical intervention.

3. Atrophy
Definition: Atrophy is the decrease in cell size and function due to a reduction in the
workload or stimulation.

Mechanism: Atrophy occurs when cells receive less stimulus or undergo reduced functional
activity. This could be due to decreased nutrient supply, lack of use, or hormonal changes.
Cells reduce their size by decreasing the synthesis of proteins and organelles.

Example: Skeletal muscle atrophy can occur in individuals who are bedridden or have been
immobilized for extended periods. The lack of physical activity leads to a decrease in muscle
mass and strength.

Consequences: Atrophy can lead to functional impairment of organs and tissues. For
instance, muscle atrophy can significantly impact mobility and strength, while atrophy of the
brain can contribute to cognitive decline in neurodegenerative diseases.

4. Metaplasia

Definition: Metaplasia is the replacement of one differentiated cell type with another, usually
in response to chronic stress or injury.

Mechanism: This adaptation involves the reprogramming of stem cells to produce a different
cell type better suited to the new environment. Metaplasia often occurs as a protective
mechanism to cope with adverse conditions.

Example: In chronic smokers, the normal ciliated columnar epithelial cells of the respiratory
tract can be replaced by stratified squamous epithelial cells. This change helps to protect the
respiratory tract from the damaging effects of smoke but can also impair normal respiratory
function.

Consequences: While metaplasia can be adaptive, it can also predispose individuals to further
complications. For instance, in the respiratory tract, metaplasia caused by smoking can
increase the risk of developing cancer.

5. Dysplasia

Definition: Dysplasia is an abnormal change in cell size, shape, and organization, often seen
as a precursor to cancer.

Mechanism: Dysplasia involves disorganized growth and is often associated with chronic
irritation or inflammation. The cells may appear atypical, with variations in size and shape,
but are not yet cancerous.

Example: Cervical dysplasia is commonly detected through Pap smears and can indicate pre-
cancerous changes in cervical cells due to persistent human papillomavirus (HPV) infection.
 Consequences: Dysplasia is considered a risk factor for the development of cancer and often
requires monitoring or intervention to prevent progression to malignancy.

2. Define cell injury? Describe the causes and types of Cell injury.

Cell injury refers to the damage or disruption of cellular structures and functions that impairs the
cell's ability to maintain homeostasis and perform its normal functions. This injury can result
from various external or internal factors, and if severe or prolonged, it can lead to cell death.
Understanding cell injury is crucial for diagnosing and treating a wide range of diseases and
conditions. Here's a detailed overview of the causes and types of cell injury:

Causes of Cell Injury

1. Physical Agents
o Trauma: Physical injury, such as cuts or fractures, can cause cell damage.
o Temperature Extremes: Extreme heat can cause burns, while extreme cold can
lead to frostbite. Both conditions disrupt cellular structures and functions.
o Radiation: Ionizing radiation (e.g., X-rays, gamma rays) and non-ionizing
radiation (e.g., UV rays) can damage cellular DNA and other cellular
components.
2. Chemical Agents
o Toxins: Environmental toxins (e.g., heavy metals, pesticides) and drugs (e.g.,
alcohol, certain medications) can impair cellular functions and structures.
o Poisons: Specific poisons, such as cyanide or carbon monoxide, can interfere with
cellular respiration or other critical processes.
3. Biological Agents
o Infections: Bacteria, viruses, fungi, and parasites can invade cells, leading to cell
injury through direct damage or by triggering inflammatory responses.
o Inflammatory Responses: Chronic inflammation caused by infections or
autoimmune conditions can result in prolonged cell injury.
4. Nutritional Imbalances
o Deficiencies: Lack of essential nutrients (e.g., vitamins, minerals) can impair
cellular functions and lead to injury. For instance, vitamin C deficiency can cause
scurvy, affecting collagen synthesis.
o Excesses: Overabundance of certain nutrients, such as excessive cholesterol, can
lead to cellular dysfunction and diseases like atherosclerosis.
5. Genetic Factors
o Inherited Mutations: Genetic mutations can lead to cellular dysfunction or
disease, such as in conditions like cystic fibrosis or muscular dystrophy.
6. Hypoxia and Ischemia
o Hypoxia: Reduced oxygen availability impairs cellular respiration, leading to
decreased ATP production and potential cell injury.
o Ischemia: Reduced blood flow to tissues can cause both oxygen and nutrient
deficiencies, leading to cellular injury and death.
7. Immune Reactions
 o Autoimmune Diseases: In autoimmune diseases, the immune system mistakenly
targets and damages normal cells.
o Allergic Reactions: Severe allergic responses can cause cell injury through
inflammatory mediators.

Types of Cell Injury

1. Reversible Injury
o Description: This type of injury is characterized by cellular damage that can be
repaired if the injurious stimulus is removed. The cell retains its ability to recover
and restore normal function.
o Examples: Swelling due to impaired ion pumps (e.g., hydropic change), fatty
changes due to accumulation of lipids (e.g., in the liver).
2. Irreversible Injury
o Description: Irreversible injury results in severe damage to cellular structures that
cannot be repaired, leading to cell death. This type of injury often progresses to
necrosis or apoptosis.
o Examples: Severe mitochondrial damage, irreversible loss of membrane integrity,
and profound DNA damage.

3. Define inflammation? List the difference between acute and chronic inflammation. Write
short note on cardinal signs of inflammation

Inflammation is a complex biological response of tissues to harmful stimuli such as pathogens,

damaged cells, or irritants. It is a protective mechanism aimed at eliminating the initial cause of
cell injury, clearing out dead cells, and establishing a repair process. Inflammation can be
classified into two main types: acute and chronic.

Differences between Acute and Chronic Inflammation

1. Duration and Onset

• Acute Inflammation: Rapid onset, occurring within minutes to hours. It is typically short-lived
and lasts for a few days.
• Chronic Inflammation: Develops gradually over days to years and persists for longer periods,
sometimes indefinitely.

2. Cause

• Acute Inflammation: Often triggered by infections, physical injury, or harmful agents. It is

usually the initial response to these stimuli.
• Chronic Inflammation: Results from persistent stimuli such as chronic infections, autoimmune
diseases, or prolonged exposure to irritants.
3. Cellular Infiltrate

• Acute Inflammation: Characterized by the predominance of neutrophils, which are the first
responders to infection or injury.
• Chronic Inflammation: Involves a mix of lymphocytes, macrophages, and plasma cells. These
cells are involved in prolonged immune responses and tissue remodeling.

4. Tissue Damage and Repair

• Acute Inflammation: Typically involves a short-term injury with a focus on resolving the cause
and beginning repair. Tissue damage is usually minimal and reversible.
• Chronic Inflammation: Often leads to ongoing tissue damage, fibrosis, and altered tissue
architecture due to prolonged immune activation and repair processes.

5. Clinical Features

• Acute Inflammation: Often associated with local symptoms such as redness, heat, swelling, and
pain. Systemic signs may include fever and leukocytosis.
• Chronic Inflammation: May not present with prominent symptoms initially and is often
associated with chronic disease manifestations, such as tissue fibrosis or functional impairment.

Cardinal Signs of Inflammation

The cardinal signs of inflammation, first described by the Roman physician Celsus, are:

1. Rubor (Redness)

• Description: Redness of the affected area due to increased blood flow (hyperemia). This results
from the dilation of blood vessels (vasodilation) in response to inflammatory mediators.
• Mechanism: Proinflammatory mediators like histamine and prostaglandins cause blood vessels
to widen, allowing more blood to reach the inflamed tissue.

2. Calor (Heat)

• Description: Increased temperature in the affected area. This is usually noticeable in peripheral
tissues.
• Mechanism: The increased blood flow not only brings more immune cells but also raises the
temperature in the local area due to the higher volume of warm blood.

3. Tumor (Swelling)

• Description: Swelling of the tissue due to the accumulation of fluid, cells, and proteins in the
interstitial spaces.
• Mechanism: Increased permeability of blood vessels allows fluid, plasma proteins, and
leukocytes to leak into the tissue, causing edema.

4. Dolor (Pain)
 • Description: Pain or discomfort at the site of inflammation.
• Mechanism: The release of chemicals like prostaglandins and bradykinin stimulates pain
receptors (nociceptors) in the affected tissues. Swelling can also compress surrounding nerves,
contributing to pain.

5. Functio Laesa (Loss of Function)

• Description: Impaired function of the affected tissue or organ.

• Mechanism: Due to pain, swelling, and tissue damage, the normal function of the affected area
can be compromised. For example, inflammation in a joint can lead to reduced mobility.

4. Define Thrombus and Embolism? Write difference between arterial and venous
thrombus.

1. Thrombus

A thrombus is a blood clot that forms within a blood vessel or the heart. It is composed of
aggregated platelets, red blood cells, white blood cells, and fibrin. Thrombosis is the process of
clot formation, which can obstruct blood flow in the affected vessel.

2. Embolism

An embolism occurs when a solid, liquid, or gas mass (called an embolus) travels through the
bloodstream and becomes lodged in a distant vessel, causing a blockage. This blockage can
impede blood flow and lead to tissue damage or organ dysfunction.

Differences between Arterial and Venous Thrombus

1. Location

• Arterial Thrombus: Forms in arteries, which carry oxygen-rich blood away from the
heart to the body's tissues. Common sites include coronary arteries (leading to heart
attacks), cerebral arteries (leading to strokes), and peripheral arteries.
• Venous Thrombus: Forms in veins, which return deoxygenated blood back to the heart.
Common sites include deep veins of the legs (leading to deep vein thrombosis, or DVT)
and the veins of the pelvis.

2. Composition

• Arterial Thrombus: Typically composed of a platelet-rich core with a fibrin meshwork.

The thrombus is usually more cellular and has a higher platelet content.
• Venous Thrombus: Typically composed of a fibrin-rich core with red blood cells and
fewer platelets. The thrombus is often softer and less organized than arterial thrombi.

3. Pathogenesis
 • Arterial Thrombus: Often associated with conditions that promote platelet activation
and aggregation, such as atherosclerosis (plaque buildup), hypertension, and high
cholesterol levels. The rupture of atherosclerotic plaques can trigger thrombus formation.
• Venous Thrombus: Often associated with conditions that cause blood stasis,
hypercoagulability, or endothelial injury. Common risk factors include prolonged
immobility (e.g., after surgery or long flights), chronic venous insufficiency, and genetic
predispositions to clotting disorders.

4. Clinical Consequences

• Arterial Thrombus: Can lead to acute ischemia in the tissues supplied by the affected
artery. This can result in severe complications such as myocardial infarction (heart
attack), ischemic stroke, or limb ischemia.
• Venous Thrombus: Can lead to complications such as pulmonary embolism if the
thrombus breaks loose and travels to the lungs. DVT can also result in chronic venous
insufficiency or post-thrombotic syndrome.

5. Treatment and Management

• Arterial Thrombus: Often treated with antiplatelet agents (e.g., aspirin, clopidogrel) and
thrombolytics (medications that dissolve clots). Surgical interventions may also be
necessary, such as angioplasty or stent placement.
• Venous Thrombus: Typically managed with anticoagulants (e.g., heparin, warfarin,
direct oral anticoagulants) to prevent further clot formation and reduce the risk of
embolism. Thrombolytics may be used in severe cases.

5. Define Neoplasia? Write the difference between benign and malignant tumors.

Neoplasia refers to the process of abnormal and uncontrolled cell growth that leads to the
formation of a neoplasm, commonly known as a tumor. Neoplasms can be benign or malignant
and result from genetic mutations that cause cells to proliferate excessively. Unlike normal tissue
growth, which is regulated and stops when the tissue reaches its proper size, neoplastic growth
continues unchecked.

Differences Between Benign and Malignant Tumors

1. Definition

• Benign Tumors: Non-cancerous growths that typically grow slowly and do not invade
surrounding tissues. They are generally well-defined and localized. Benign tumors
usually do not spread to other parts of the body.
• Malignant Tumors: Cancerous growths characterized by uncontrolled growth, invasion
of surrounding tissues, and the ability to spread (metastasize) to other parts of the body.
Malignant tumors are often aggressive and can be life-threatening.
2. Growth Rate

• Benign Tumors: Generally have a slower growth rate and may remain stable in size for
long periods. They often have well-defined borders and grow in a more organized
manner.
• Malignant Tumors: Exhibit rapid and uncontrolled growth. They often invade adjacent
tissues and structures, leading to irregular and poorly defined borders.

3. Invasion

• Benign Tumors: Do not invade surrounding tissues. They grow expansively, pushing
against adjacent structures rather than infiltrating them.
• Malignant Tumors: Have the ability to invade and destroy surrounding tissues. They
can penetrate local tissues and organs, disrupting their normal function.

4. Metastasis

• Benign Tumors: Do not spread to other parts of the body. They remain localized to their
site of origin.
• Malignant Tumors: Can metastasize, meaning they can spread to distant sites through
the bloodstream or lymphatic system. This ability to spread is a key characteristic of
malignancy.

5. Histological Appearance

• Benign Tumors: Tend to have a histological appearance that closely resembles normal
tissue. The cells are well-differentiated, meaning they maintain a structure and function
similar to the cells of the tissue from which they originated.
• Malignant Tumors: Often have a histological appearance that is markedly different from
normal tissue. The cells may be poorly differentiated, meaning they have abnormal
shapes and sizes, and exhibit significant architectural disorganization.

6. Clinical Behavior

• Benign Tumors: Generally have a good prognosis and can often be treated effectively
with surgical removal. They are less likely to be life-threatening unless they cause
significant pressure on vital structures or organs.
• Malignant Tumors: Often require more aggressive treatment approaches, including
surgery, chemotherapy, radiation therapy, or targeted therapies. The prognosis can be
poor depending on the type, stage, and grade of the cancer, as well as the overall health of
the patient.

7. Recurrence

• Benign Tumors: Rarely recur after complete removal. They usually have a lower
tendency to come back after treatment.
 • Malignant Tumors: Have a higher risk of recurrence, especially if not completely
removed or if metastasis has occurred. Surveillance and follow-up are often necessary to
monitor for recurrence.

8. Systemic Effects

• Benign Tumors: Typically do not cause systemic symptoms or have significant effects
on overall health unless they cause mechanical obstruction or pressure on vital organs.
• Malignant Tumors: Can cause systemic effects such as weight loss, fatigue, and
paraneoplastic syndromes (conditions associated with cancer that are not directly related
to the tumor's local effects).

6. Define Tuberculosis? Describe etiology, types, pathogenesis of tuberculosis.

Tuberculosis (TB) is a contagious bacterial infection primarily caused by Mycobacterium

tuberculosis. It mainly affects the lungs (pulmonary tuberculosis) but can also involve other parts
of the body such as the kidneys, spine, and brain (extra pulmonary tuberculosis). TB is
characterized by the formation of granulomas, which are clusters of immune cells attempting to
contain the infection.

Etiology of Tuberculosis

1. Causative Agent

• Mycobacterium tuberculosis: The primary bacterium responsible for TB. It is an aerobic, acid-
fast bacillus that has a unique waxy cell wall, which contributes to its resistance to many
common disinfectants and makes it difficult for the immune system to clear.

2. Transmission

• Airborne Droplets: TB is transmitted from person to person through the inhalation of airborne
droplets expelled when an infected person coughs, sneezes, or talks. These droplets contain M.
tuberculosis and can be inhaled into the lungs of a susceptible individual.

3. Risk Factors

• Immune System Status: Individuals with weakened immune systems, such as those with
HIV/AIDS or on immunosuppressive therapy, are at higher risk.
• Socioeconomic Factors: Poverty, overcrowding, and poor living conditions increase the risk of
TB transmission.
• Comorbid Conditions: Conditions like diabetes, chronic kidney disease, or silicosis can
predispose individuals to TB.
• Geographic Location: High prevalence in certain regions, such as sub-Saharan Africa, parts of
Asia, and Eastern Europe.
Types of Tuberculosis

1. Pulmonary Tuberculosis

• Description: The most common form of TB, affecting the lungs. It is characterized by symptoms
such as persistent cough, hemoptysis (coughing up blood), chest pain, and weight loss.

2. Extrapulmonary Tuberculosis

• Description: TB that occurs outside the lungs. It can affect various organs including:
o Lymph Nodes: Known as lymphatic TB.
o Genitourinary System: Known as renal TB.
o Skeletal System: Including the spine (Pott’s disease).
o Central Nervous System: Including meningitis (TB meningitis).
o Pleura: Causing pleural effusion.

3. Latent Tuberculosis Infection (LTBI)

• Description: A state where individuals are infected with M. tuberculosis but do not exhibit
symptoms and are not infectious. LTBI can progress to active TB if the immune system becomes
compromised.

4. Active Tuberculosis

• Description: A state where M. tuberculosis is actively replicating, leading to symptoms and

potentially infectious to others.

Pathogenesis of Tuberculosis

1. Infection Initiation

• Inhalation: The infection begins when droplets containing M. tuberculosis are inhaled and reach
the alveoli in the lungs.

2. Initial Immune Response

• Phagocytosis: Macrophages in the alveoli phagocytize the bacteria. However, M. tuberculosis

has evolved mechanisms to survive within these immune cells, preventing their destruction.

3. Formation of Granulomas

• Granuloma Formation: The immune system responds by forming granulomas, also known as
tubercles. These are organized collections of macrophages, lymphocytes, and fibroblasts that
attempt to contain the infection.
• Caseation Necrosis: Within the granulomas, some cells may undergo necrosis, resulting in a
cheese-like appearance (caseous necrosis). This necrotic tissue can be a hallmark of active TB.
4. Chronic Infection

• Latency: In many cases, the immune response controls the infection, leading to latent TB. The
bacteria remain in a dormant state within the granulomas.

5. Active Disease

• Reactivation: In cases where the immune system is compromised or weakened, latent TB can
reactivate. The bacteria multiply, break out of granulomas, and spread to other parts of the
lungs or other organs, leading to active TB disease.

6. Dissemination

• Spread: Active TB can cause the bacteria to spread to other organs through the bloodstream or
lymphatic system. This can result in extra pulmonary TB.

7. Define Necrosis and apoptosis? Write in detail types of necrosis.

1. Necrosis

Necrosis is a form of cell death resulting from acute damage or injury to the cell that leads to its
uncontrolled death and disruption of surrounding tissue. It typically occurs due to factors such as
ischemia (lack of blood flow), toxins, or infections, and often results in inflammation. Necrosis is
characterized by cellular swelling, membrane rupture, and subsequent inflammation in the
affected tissue.

2. Apoptosis

Apoptosis is a programmed form of cell death that occurs in a controlled, regulated manner,
essential for maintaining cellular homeostasis and tissue development. Unlike necrosis, apoptosis
does not provoke an inflammatory response. It involves a series of biochemical events leading to
cell shrinkage, DNA fragmentation, and formation of apoptotic bodies, which are then
phagocytosed by neighboring cells or macrophages.

Types of Necrosis

Necrosis can be classified into several types, each with distinct characteristics and causes:

1. Coagulative Necrosis

• Description: Coagulative necrosis is characterized by the preservation of the basic tissue

architecture but with cellular proteins becoming denatured and coagulated. The affected
tissue appears firm and pale.
 • Cause: Typically results from ischemia or infarction, where blood supply to a tissue is
obstructed. Common in myocardial infarction (heart attack) and in cases of renal
infarction.
• Pathogenesis: Loss of blood supply leads to a lack of oxygen (hypoxia) and nutrients,
causing cell death. The cells undergo coagulation, but the tissue framework remains
somewhat intact.

2. Liquefactive Necrosis

• Description: Liquefactive necrosis involves the transformation of tissue into a liquid

viscous mass, often resulting in the formation of an abscess.
• Cause: Commonly associated with bacterial infections that lead to a pus-forming process,
or in cases of brain infarction. It occurs due to the enzymatic digestion of dead cells.
• Pathogenesis: The process of enzymatic digestion liquefies the tissue, often due to the
action of neutrophil enzymes in response to an infection or other causes of cell death.

3. Caseous Necrosis

• Description: Caseous necrosis is characterized by a cheese-like (caseous) appearance of

the affected tissue, resembling cottage cheese. The tissue architecture is lost, and the
necrotic area appears dry and granular.
• Cause: Typically associated with tuberculosis infections. It is also seen in certain types of
fungal infections.
• Pathogenesis: It is a result of a granulomatous inflammatory response where
macrophages transform into epithelioid cells and form a granuloma. The central area of
the granuloma undergoes caseous necrosis.

4. Fat Necrosis

• Description: Fat necrosis involves the destruction of adipose tissue. The affected tissue
appears chalky and has a necrotic, soapy appearance.
• Cause: Commonly seen in acute pancreatitis or trauma to fat tissue. It can also occur
following abdominal surgery or in some cases of breast cancer.
• Pathogenesis: Lipases (enzymes that break down fats) break down triglycerides into free
fatty acids, which then combine with calcium to form soap-like substances
(saponification).

5. Fibrinoid Necrosis

• Description: Fibrinoid necrosis is characterized by the deposition of fibrin-like

proteinaceous material in the walls of blood vessels, giving a "fibrinoid" appearance
under the microscope.
 • Cause: Often seen in autoimmune diseases such as systemic lupus erythematosus (SLE)
and in certain types of vasculitis.
• Pathogenesis: It results from the deposition of immune complexes and fibrin in the
vessel walls, leading to fibrin-like staining in the tissue.

8. Describe the vascular and cellular changes in acute inflammation.

Acute inflammation is the body’s immediate and early response to tissue injury, infection, or
harmful stimuli. It involves complex vascular and cellular changes designed to eliminate the
injurious agent and facilitate tissue repair. Here’s a detailed look at these changes:

Vascular Changes in Acute Inflammation

1. Vasodilation
o Description: The first response to inflammation is the dilation of blood vessels,
particularly the arterioles. This results in an increase in blood flow to the affected area.
o Mechanism: Mediated by chemical signals such as histamine, prostaglandins, and nitric
oxide. These mediators relax the smooth muscle in the vessel walls, leading to increased
vessel diameter.
o Effect: Vasodilation causes the classic signs of inflammation: redness (rubor) and heat
(calor).
2. Increased Vascular Permeability
o Description: The permeability of the blood vessels increases, allowing plasma proteins
and leukocytes to exit the bloodstream and enter the tissue.
o Mechanism: This is achieved through the retraction of endothelial cells lining the
vessels, which creates gaps between cells. Mediators like histamine, bradykinin, and
leukotrienes play a key role in this process.
o Effect: Increased permeability leads to the accumulation of fluid in the interstitial space,
causing swelling (tumor) and contributing to the development of edema.
3. Exudation
o Description: The process by which fluid, proteins, and cells leave the bloodstream and
accumulate in the tissue. This fluid is known as exudate.
o Types:
▪ Serous Exudate: Clear, watery fluid typical of mild inflammation (e.g., blisters).
▪ Fibrinous Exudate: Contains fibrinogen that forms fibrin, contributing to a thick,
sticky fluid (e.g., in cases of severe inflammation).
▪ Purulent Exudate: Contains pus, which is a mix of dead leukocytes, bacteria, and
tissue debris (e.g., abscesses).
4. Stasis and Sluggish Blood Flow
o Description: Following the initial vasodilation, blood flow becomes sluggish due to
increased vessel diameter and increased viscosity of the blood.
o Mechanism: Sluggish flow allows for better interaction between leukocytes and the
endothelium, facilitating leukocyte adhesion and migration.

Cellular Changes in Acute Inflammation

1. Leukocyte Recruitment
 o Description: The movement of leukocytes (white blood cells) from the bloodstream into
the inflamed tissue.
o Process:
▪ Margination: Leukocytes move closer to the vessel walls as blood flow slows.
▪ Rolling: Leukocytes adhere loosely to the endothelium and roll along the vessel
wall due to interactions with adhesion molecules (e.g., selectins).
▪ Adhesion: Leukocytes adhere firmly to the endothelium via integrins binding to
adhesion molecules (e.g., ICAM-1).
▪ Transmigration: Leukocytes migrate through the endothelial cell junctions into
the interstitial tissue. This process is known as diapedesis or extravasation.
2. Phagocytosis
o Description: The process by which leukocytes engulf and destroy pathogens, dead cells,
and debris.
o Types of Phagocytes:
▪ Neutrophils: The first responders in acute inflammation. They are highly
effective in engulfing and killing bacteria and fungi.
▪ Macrophages: Arise from monocytes that migrate into tissues. They play a role
in clearing debris and orchestrating the inflammatory response by secreting
cytokines.
3. Activation and Release of Inflammatory Mediators
o Description: Activated leukocytes release various mediators that amplify the
inflammatory response.
o Examples:
▪ Cytokines: Proteins such as tumor necrosis factor-alpha (TNF-α), interleukins
(e.g., IL-1, IL-6) that mediate inflammation and influence the behavior of other
cells.
▪ Chemokines: Attract additional leukocytes to the site of inflammation.
▪ Enzymes: Proteases and reactive oxygen species (ROS) released by leukocytes
can damage pathogens but also cause tissue damage.
4. Resolution of Inflammation
o Description: The final phase of acute inflammation where the inflammatory response
subsides, and tissue repair begins.
o Mechanism: Involves the removal of inflammatory cells, resolution of vascular changes,
and repair of damaged tissue. Anti-inflammatory cytokines and mediators (e.g., lipoxins,
resolvins) help to resolve the inflammation and promote healing.

9. Define Edema? Describe Types and Pathophysiology of edema.

Edema is the medical term for swelling caused by the accumulation of excess fluid in the body's
tissues. This fluid buildup can occur in various parts of the body, including the skin, organs, and
other tissues, and can lead to noticeable swelling and discomfort.

Types of Edema

1. Peripheral Edema:
 o Location: Typically affects the legs, ankles, and feet.
o Causes: Often related to issues with the circulatory system, lymphatic system, or
kidneys. Common causes include heart failure, chronic venous insufficiency, or
prolonged standing.
2. Pulmonary Edema:
o Location: Accumulation of fluid in the lungs.
o Causes: Often associated with congestive heart failure, acute respiratory distress
syndrome (ARDS), or high altitude. This type of edema can be life-threatening as
it impairs gas exchange in the lungs.
3. Cerebral Edema:
o Location: Swelling in the brain.
o Causes: May result from head injury, stroke, infection (like meningitis), or brain
tumors. Cerebral edema is a medical emergency because it can increase
intracranial pressure and damage brain tissue.
4. Lymphedema:
o Location: Typically affects the arms or legs.
o Causes: Occurs when the lymphatic system is compromised, leading to the
accumulation of lymph fluid. This can be due to lymph node removal, cancer
treatment, or congenital defects in the lymphatic system.
5. Ascites:
o Location: Accumulation of fluid in the abdominal cavity.
o Causes: Often associated with liver cirrhosis, heart failure, or cancer. It can cause
significant discomfort and distension of the abdomen.
6. Angioedema:
o Location: Rapid swelling beneath the skin, often around the eyes, lips, throat, or
genitals.
o Causes: Typically related to allergic reactions, hereditary conditions, or as a side
effect of medications like ACE inhibitors.

Pathophysiology of Edema

Edema occurs when there is an imbalance in the forces that regulate the movement of fluid
between the blood vessels and the tissues. The primary mechanisms involved in the development
of edema include:

1. Increased Capillary Hydrostatic Pressure:

o When the pressure within the capillaries (small blood vessels) increases, it pushes
more fluid out of the blood vessels and into the surrounding tissues. This can
occur due to heart failure, venous obstruction, or kidney disease.
2. Decreased Plasma Oncotic Pressure:
o Plasma proteins, particularly albumin, help retain fluid within the blood vessels.
When the level of these proteins decreases (due to liver disease, malnutrition, or
nephrotic syndrome), fluid leaks out into the tissues, leading to edema.
3. Increased Capillary Permeability:
o Inflammatory conditions, infections, or allergic reactions can cause the capillaries
to become more permeable, allowing fluid and proteins to leak into the tissues.
4. Lymphatic Obstruction:
o The lymphatic system is responsible for draining excess fluid from tissues. If this
system is obstructed or damaged (as in lymphedema), fluid accumulates, leading
to edema.
5. Sodium and Water Retention:
o Conditions that lead to excessive retention of sodium and water by the kidneys
(such as kidney disease or certain medications) can increase blood volume,
leading to increased hydrostatic pressure and edema.
 Unit 2:
1. Define atherosclerosis. Discuss the risk factors, etiopathogenesis of atherosclerosis.

Atherosclerosis is a chronic disease characterized by the hardening and narrowing of the arteries
due to the buildup of plaque, which is composed of fat, cholesterol, calcium, and other
substances found in the blood. This condition leads to reduced blood flow, which can result in
serious cardiovascular complications such as heart attacks, strokes, and peripheral artery disease.

Risk Factors for Atherosclerosis

1. Non-Modifiable Risk Factors:

o Age: The risk increases with age, especially after 45 years for men and 55 years
for women.
o Gender: Men are generally at higher risk at younger ages, although the risk for
women increases and can surpass men after menopause.
o Family History: A family history of cardiovascular disease can increase the risk
of atherosclerosis.
2. Modifiable Risk Factors:
o Hyperlipidemia (High Cholesterol): Elevated levels of low-density lipoprotein
(LDL) cholesterol, often referred to as "bad" cholesterol, contribute to plaque
formation. Low levels of high-density lipoprotein (HDL) cholesterol, known as
"good" cholesterol, also increase risk.
o Hypertension (High Blood Pressure): High blood pressure can damage the inner
lining of arteries, making them more susceptible to plaque buildup.
o Smoking: Tobacco smoke damages the endothelium (the inner lining of blood
vessels), increases LDL cholesterol, and lowers HDL cholesterol.
o Diabetes Mellitus: High blood sugar levels contribute to endothelial damage and
increase the risk of plaque formation.
o Obesity: Excess body weight, especially when concentrated around the abdomen,
is associated with higher levels of LDL cholesterol, lower HDL cholesterol, and
higher blood pressure.
o Sedentary Lifestyle: Lack of physical activity contributes to obesity,
hypertension, and unhealthy cholesterol levels.
o Unhealthy Diet: Diets high in saturated fats, trans fats, cholesterol, and refined
sugars can contribute to the development of atherosclerosis.
o Excessive Alcohol Consumption: Can raise blood pressure and contribute to
high cholesterol levels.
3. Emerging Risk Factors:
o Chronic Inflammation: Conditions like chronic infections or autoimmune
diseases can promote atherosclerosis.
o Elevated Homocysteine Levels: High levels of this amino acid are associated
with an increased risk of atherosclerosis.
o Oxidative Stress: Imbalance between free radicals and antioxidants in the body
can lead to endothelial damage and promote atherosclerosis.
Etiopathogenesis of Atherosclerosis

The development of atherosclerosis is a complex, multifactorial process that involves several

stages:

1. Endothelial Injury:
o The initial step in atherosclerosis is damage to the endothelial lining of the
arteries. This injury can be caused by factors such as hypertension, smoking, high
cholesterol levels, and diabetes. The damaged endothelium becomes more
permeable to lipids and inflammatory cells.
2. Lipoprotein Accumulation:
o Low-density lipoprotein (LDL) cholesterol penetrates the damaged endothelium
and accumulates in the subendothelial space. LDL particles become oxidized,
making them more atherogenic (likely to cause atherosclerosis).
3. Monocyte Adhesion and Migration:
o The endothelial injury promotes the expression of adhesion molecules, which
attract circulating monocytes (a type of white blood cell). These monocytes
migrate into the arterial wall, where they differentiate into macrophages.
4. Formation of Foam Cells:
o Macrophages engulf the oxidized LDL through a process called phagocytosis,
leading to the formation of foam cells. These foam cells accumulate in the arterial
wall, forming fatty streaks, which are the earliest visible signs of atherosclerosis.
5. Smooth Muscle Cell Migration and Proliferation:
o Smooth muscle cells from the media layer of the artery migrate to the intima (the
innermost layer of the artery) and proliferate. These cells produce extracellular
matrix components such as collagen, which contribute to the formation of a
fibrous cap over the plaque.
6. Plaque Formation:
o The combination of foam cells, smooth muscle cells, lipids, and extracellular
matrix forms an atherosclerotic plaque. As the plaque grows, it narrows the
arterial lumen, reducing blood flow.
7. Plaque Rupture and Thrombosis:
o Over time, the fibrous cap of the plaque may become thin and prone to rupture. If
the plaque ruptures, it exposes the underlying tissue, which triggers the formation
of a blood clot (thrombus). This clot can further narrow or completely block the
artery, leading to ischemia (reduced blood flow) and potentially causing a heart
attack or stroke.

2. Define viral hepatitis? Name 5 hepatotropic viruses. Write morphology of liver in

acute viral hepatitis.

Viral hepatitis is an inflammation of the liver caused by infection with hepatotropic viruses.
These viruses specifically target the liver, leading to a range of symptoms that can vary from
mild to severe, including jaundice, fatigue, and abdominal pain. The severity of viral hepatitis
can range from an acute, self-limiting illness to chronic liver disease, potentially leading to
cirrhosis, liver failure, or liver cancer.
Hepatotropic Viruses

The five primary hepatotropic viruses responsible for viral hepatitis are:

1. Hepatitis A virus (HAV)

2. Hepatitis B virus (HBV)
3. Hepatitis C virus (HCV)
4. Hepatitis D virus (HDV)
5. Hepatitis E virus (HEV)

These viruses differ in their modes of transmission, epidemiology, and potential to cause chronic
infection.

Morphology of Liver in Acute Viral Hepatitis

In acute viral hepatitis, the liver undergoes various histopathological changes. The following are
the key morphological features observed in the liver during acute viral hepatitis:

1. Hepatocyte Injury:
o Ballooning Degeneration: Hepatocytes (liver cells) become swollen and
vacuolated due to water accumulation. This change is indicative of cell injury and
dysfunction.
o Councilman Bodies (Apoptotic Bodies): Hepatocytes undergoing apoptosis
(programmed cell death) shrink and form eosinophilic (pink-staining) round
bodies, which are known as Councilman bodies.
2. Inflammation:
o Portal Inflammation: There is an infiltration of inflammatory cells, primarily
lymphocytes, in the portal tracts (areas where blood vessels, bile ducts, and nerves
enter the liver). This is a hallmark of acute hepatitis.
o Lobular Inflammation: Inflammatory cells may also be scattered throughout the
liver lobules, especially around injured or necrotic hepatocytes.
3. Hepatocyte Necrosis:
o Focal or Spotty Necrosis: Small clusters of necrotic hepatocytes are scattered
throughout the liver lobules. This is often accompanied by the infiltration of
inflammatory cells.
o Bridging Necrosis: In more severe cases, necrosis may extend across adjacent
lobules, forming bridges between portal tracts or central veins.
4. Cholestasis:
o Intrahepatic Cholestasis: Impairment of bile flow may occur, leading to the
accumulation of bile pigment within hepatocytes or bile canaliculi. This can
contribute to jaundice, a common clinical sign of hepatitis.
5. Regeneration:
o Regenerative Hepatocytes: Following injury, the liver attempts to regenerate.
Regenerating hepatocytes may appear larger with prominent nucleoli and mitotic
figures (indicative of cell division).
6. Sinusoidal Changes:
 o Sinusoidal Lymphocytosis: Inflammation can also involve the liver sinusoids,
with lymphocytes and other inflammatory cells infiltrating these spaces.

3. Classify urinary tract infections? Write about acute pyelonephritis.

Urinary Tract Infections (UTIs) are infections that can affect any part of the urinary system,
including the kidneys, ureters, bladder, and urethra. UTIs are typically classified based on the
location of the infection, the severity, and whether they are complicated or uncomplicated.

Classification of Urinary Tract Infections

1. By Location:
o Lower Urinary Tract Infection:
▪ Cystitis: Infection of the bladder.
▪ Urethritis: Infection of the urethra.
o Upper Urinary Tract Infection:
▪ Pyelonephritis: Infection of the kidneys.
▪ Ureteritis: Infection of the ureters (less common and often secondary to kidney
or bladder infection).
2. By Severity:
o Uncomplicated UTI:
▪ Occurs in otherwise healthy individuals with normal urinary tract anatomy and
function. Typically limited to the lower urinary tract (e.g., cystitis).
o Complicated UTI:
▪ Occurs in individuals with structural or functional abnormalities of the urinary
tract, or in the presence of other complicating factors such as indwelling
catheters, immunosuppression, or multidrug-resistant organisms.
3. By Causative Organism:
o Bacterial UTI: The most common type, often caused by Escherichia coli.
o Fungal UTI: Less common, usually occurring in immunocompromised individuals or
those with indwelling catheters, often caused by Candida species.
o Viral UTI: Rare, usually seen in immunocompromised patients.

Acute Pyelonephritis

Acute pyelonephritis is a sudden and severe kidney infection that typically affects the renal
pelvis and interstitial tissue of the kidney. It is considered an upper urinary tract infection and
can lead to serious complications if not treated promptly.

Etiology

• Bacterial Infection: The most common causative organism is Escherichia coli, which is
responsible for about 70-90% of cases. Other bacteria include Proteus mirabilis, Klebsiella
pneumoniae, and Enterococcus faecalis.
• Ascending Infection: Acute pyelonephritis usually results from an ascending infection, where
bacteria from the bladder travel up the ureters to the kidneys.
 • Hematogenous Spread: Less commonly, bacteria may reach the kidneys through the
bloodstream, especially in patients with bacteremia or sepsis.

Risk Factors

• Female Gender: Women are more susceptible due to the shorter urethra and proximity of the
urethral opening to the anus.
• Urinary Tract Obstruction: Conditions such as kidney stones, strictures, or tumors that block
urine flow can predispose to pyelonephritis.
• Vesicoureteral Reflux: Abnormal backward flow of urine from the bladder into the ureters and
kidneys, commonly seen in children.
• Diabetes Mellitus: Patients with diabetes have an increased risk due to impaired immune
response and glucosuria (glucose in urine, which promotes bacterial growth).
• Immunosuppression: Conditions like HIV/AIDS or the use of immunosuppressive drugs can
increase susceptibility.
• Pregnancy: Physiological changes during pregnancy, such as urinary stasis and increased
vesicoureteral reflux, increase the risk.

Pathophysiology

• Bacterial Invasion: Bacteria ascend from the lower urinary tract and reach the renal pelvis and
parenchyma.
• Inflammation: The bacteria trigger an inflammatory response, resulting in the infiltration of
neutrophils and other immune cells into the renal interstitium and tubules.
• Tissue Damage: The infection leads to tissue necrosis, abscess formation, and in severe cases,
the destruction of renal parenchyma.
• Systemic Spread: If untreated, the infection can spread to the bloodstream, causing sepsis and
potentially leading to multi-organ failure.

Diagnosis

• Urinalysis: Presence of pyuria (white blood cells in urine), bacteriuria, and possibly hematuria.
• Urine Culture: Essential for identifying the causative organism and determining antibiotic
sensitivity.
• Blood Tests: Elevated white blood cell count, and possibly elevated serum creatinine if there is
impaired kidney function.
• Imaging: Ultrasound or CT scan may be used to detect complications like abscesses or
obstruction.

Complications

• Chronic Pyelonephritis: Recurrent or severe acute pyelonephritis can lead to chronic kidney
damage and scarring, eventually causing chronic kidney disease.
• Renal Abscess: Localized collections of pus within the kidney tissue.
• Urosepsis: The infection may spread to the bloodstream, causing sepsis, a life-threatening
condition.
 • Papillary Necrosis: Ischemic necrosis of the renal papillae, often seen in patients with diabetes
or obstruction.

4. Describe etiology and pathogenesis of peptic ulcer.

Peptic ulcer refers to an open sore or lesion that develops on the inner lining of the stomach
(gastric ulcer) or the upper part of the small intestine (duodenal ulcer). It occurs when the
mucosal defenses that protect the gastrointestinal lining are disrupted, allowing acidic digestive
juices to erode the tissue.

Etiology of Peptic Ulcer

The development of peptic ulcers is associated with several key factors:

1. Helicobacter pylori Infection:

o Helicobacter pylori (H. pylori) is a spiral-shaped bacterium that colonizes the
gastric mucosa. It is the most common cause of peptic ulcers, responsible for
about 70-90% of duodenal ulcers and a significant number of gastric ulcers.
o The bacterium weakens the protective mucus layer in the stomach and duodenum,
making the mucosa more susceptible to damage by stomach acid.
2. Nonsteroidal Anti-Inflammatory Drugs (NSAIDs):
o NSAIDs, such as aspirin, ibuprofen, and naproxen, inhibit the enzyme
cyclooxygenase (COX), which is essential for the production of prostaglandins.
Prostaglandins help maintain the protective mucus lining of the stomach.
o By reducing prostaglandin synthesis, NSAIDs decrease mucosal defense, leading
to increased susceptibility to acid-induced injury, thus promoting ulcer formation.
3. Excessive Gastric Acid Secretion:
o Conditions that increase acid production, such as Zollinger-Ellison syndrome (a
rare condition characterized by gastrin-secreting tumors), can lead to peptic
ulcers.
o Hypersecretion of acid overwhelms the mucosal defenses, leading to ulcer
formation, particularly in the duodenum.
4. Lifestyle Factors:
o Smoking: Smoking increases the risk of developing peptic ulcers and delays
healing. It promotes acid secretion and may impair the production of bicarbonate
(a neutralizing agent) in the duodenum.
o Alcohol: Excessive alcohol consumption can irritate and erode the gastric
mucosa, increasing the risk of ulceration.
o Stress: Severe physiological stress, such as that associated with critical illness or
major surgery, can lead to "stress ulcers" due to reduced blood flow to the
stomach lining and alterations in mucosal defense mechanisms.
5. Genetic Predisposition:
o A family history of peptic ulcers can increase the risk, possibly due to inherited
factors that influence acid secretion, mucosal defense, or immune response to H.
pylori.
6. Other Contributing Factors:
 o Corticosteroids: When used in combination with NSAIDs, corticosteroids
increase the risk of peptic ulcers.
o Dietary Factors: While specific foods do not cause ulcers, spicy foods, caffeine,
and carbonated beverages can exacerbate symptoms in individuals with existing
ulcers.

Pathogenesis of Peptic Ulcer

The pathogenesis of peptic ulcer involves a complex interplay between aggressive factors (e.g.,
gastric acid, pepsin, H. pylori, NSAIDs) and defensive factors (e.g., mucus, bicarbonate, mucosal
blood flow, prostaglandins).

1. Disruption of Mucosal Defense:

o The stomach and duodenum are normally protected by a mucus-bicarbonate
barrier, which neutralizes stomach acid and prevents it from damaging the
underlying epithelial cells.
o Prostaglandins play a key role in maintaining this barrier by stimulating mucus
and bicarbonate production, enhancing blood flow to the mucosa, and promoting
cell regeneration.
2. H. pylori Infection:
o H. pylori colonizes the gastric mucosa by adhering to the epithelial cells, where it
produces enzymes like urease. Urease breaks down urea into ammonia, which
neutralizes the surrounding acid, allowing the bacteria to survive in the acidic
environment of the stomach.
o H. pylori also produces cytotoxins and induces an inflammatory response, leading
to mucosal damage and weakening the protective barrier. The resultant
inflammation and injury increase susceptibility to acid-induced ulceration.
3. NSAID-Induced Ulceration:
o NSAIDs inhibit COX enzymes, leading to reduced synthesis of protective
prostaglandins. The decrease in prostaglandins compromises the mucosal
defenses, reducing mucus and bicarbonate secretion, decreasing mucosal blood
flow, and impairing the repair of damaged epithelial cells.
o The direct irritant effect of NSAIDs on the gastric mucosa can also contribute to
ulcer formation.
4. Acid and Pepsin:
o Gastric acid, secreted by parietal cells, and pepsin, an enzyme that digests
proteins, are key aggressive factors in ulcer formation.
o In situations where acid production is excessive (e.g., in Zollinger-Ellison
syndrome) or where mucosal defenses are compromised, acid and pepsin can
erode the mucosa, leading to ulceration.
5. Inflammation and Ulcer Formation:
o Chronic inflammation due to H. pylori or other irritants leads to the recruitment of
immune cells, which release inflammatory mediators that further damage the
mucosa.
 o The ongoing cycle of mucosal injury, inflammation, and repair can result in the
formation of an ulcer, characterized by a well-demarcated area of tissue necrosis
with an inflamed base.
6. Healing and Recurrence:
o The ulcer healing process involves the regeneration of epithelial cells,
reestablishment of the mucus-bicarbonate barrier, and restoration of normal blood
flow.
o However, in the presence of persistent H. pylori infection or continued use of
NSAIDs, healing may be incomplete or followed by recurrence, leading to
chronic peptic ulcer disease.

5. Classification of breast carcinoma. What are the Prognostic and Predictive factors
of breast cancer?

Breast carcinoma is a malignant tumor that originates from the epithelial cells of the breast
tissue. It is the most common cancer in women worldwide. Breast carcinoma is classified based
on histological features, molecular characteristics, and receptor status. Understanding these
classifications is crucial for determining treatment and prognosis.

Classification of Breast Carcinoma

1. Histological Classification:
o Invasive Carcinomas:
▪ Invasive Ductal Carcinoma (IDC): The most common type, accounting for about
70-80% of all breast cancers. It originates in the milk ducts and invades
surrounding breast tissue.
▪ Invasive Lobular Carcinoma (ILC): The second most common type, accounting
for about 10-15% of cases. It originates in the lobules (glands that produce milk).
▪ Tubular Carcinoma: A subtype of IDC with a favorable prognosis, characterized
by well-formed tubular structures.
▪ Mucinous (Colloid) Carcinoma: Composed of mucus-producing cancer cells,
generally has a good prognosis.
▪ Medullary Carcinoma: Characterized by large, high-grade cells and a
lymphocytic infiltrate, often seen in younger women.
▪ Papillary Carcinoma: Rare and typically occurs in older women, characterized by
papillary structures.
▪ Metaplastic Carcinoma: A heterogeneous group of tumors with varying cellular
differentiation, typically more aggressive.
o Non-Invasive (In Situ) Carcinomas:
▪ Ductal Carcinoma In Situ (DCIS): A precursor to invasive carcinoma, confined to
the ductal system without invasion of surrounding tissue.
▪ Lobular Carcinoma In Situ (LCIS): Often considered a marker for increased
breast cancer risk, it is confined to the lobules and does not invade surrounding
tissue.
2. Molecular Classification (Based on Gene Expression Profiles):
 o Luminal A: ER-positive, PR-positive, HER2-negative, low Ki-67 index (a marker of
proliferation). These tumors are less aggressive and have a better prognosis.
o Luminal B: ER-positive, PR-positive or negative, HER2-positive or negative, higher Ki-67
index. More aggressive than Luminal A.
o HER2-Enriched: HER2-positive, ER-negative, PR-negative. These tumors are more
aggressive but may respond well to HER2-targeted therapies.
o Basal-like/Triple-Negative Breast Cancer (TNBC): ER-negative, PR-negative, HER2-
negative. These tumors are more aggressive, often found in younger women, and are
associated with a poorer prognosis.
3. Receptor Status Classification:
o Hormone Receptor-Positive:
▪ Estrogen Receptor (ER)-Positive
▪ Progesterone Receptor (PR)-Positive
o HER2-Positive: Overexpression of the HER2 (human epidermal growth factor receptor 2)
gene.
o Triple-Negative: Lacks ER, PR, and HER2 expression, making it more challenging to treat
with targeted therapies.

Prognostic and Predictive Factors of Breast Cancer

Prognostic factors provide information about the likely course and outcome of the disease, while
predictive factors indicate the likelihood of response to a particular treatment.

Prognostic Factors

1. Tumor Size:
o Larger tumors generally have a worse prognosis as they are more likely to have spread
beyond the breast.
2. Lymph Node Status:
o The presence of cancer cells in the regional lymph nodes (axillary lymph nodes) is a
strong indicator of disease spread and correlates with a worse prognosis.
3. Histological Grade:
o Tumors are graded based on how much the cancer cells resemble normal cells. Higher-
grade tumors (Grade 3) are more aggressive and have a worse prognosis compared to
lower-grade tumors (Grade 1).
4. Histological Type:
o Some histological types, such as tubular or mucinous carcinomas, have a better
prognosis than others, like metaplastic carcinoma.
5. Hormone Receptor Status:
o ER-positive and PR-positive tumors generally have a better prognosis because they are
more likely to respond to hormone therapy.
6. HER2 Status:
o HER2-positive tumors tend to be more aggressive, but they may respond well to HER2-
targeted therapies, such as trastuzumab (Herceptin).
7. Proliferation Markers (e.g., Ki-67):
o A high Ki-67 index indicates a high proliferation rate and is associated with a more
aggressive tumor and poorer prognosis.
 8. Age:
o Younger women tend to have more aggressive tumors, while older women often have
hormone receptor-positive tumors that grow more slowly.
9. Lymphovascular Invasion:
o The presence of cancer cells in the lymphatic or blood vessels within the tumor is
associated with a higher risk of metastasis and poorer prognosis.
10. Genetic Mutations (e.g., BRCA1/BRCA2):
o Mutations in the BRCA1 or BRCA2 genes are associated with a higher risk of developing
breast cancer and often correlate with more aggressive tumor types.

Predictive Factors

1. Hormone Receptor Status:

o ER-positive and PR-positive tumors are more likely to respond to hormone therapy (e.g.,
tamoxifen, aromatase inhibitors).
2. HER2 Status:
o HER2-positive tumors are more likely to respond to HER2-targeted therapies (e.g.,
trastuzumab, pertuzumab).
3. Genetic Profiling (e.g., Oncotype DX, MammaPrint):
o These tests assess the expression of specific genes in the tumor to predict the likelihood
of benefit from chemotherapy and the risk of recurrence.
4. Chemotherapy Sensitivity:
o Certain tumor characteristics, such as high Ki-67 or triple-negative status, may indicate a
higher likelihood of responding to chemotherapy.

6. Describe Etiology and Pathogenesis of breast carcinoma?

Breast carcinoma is a complex disease with multifactorial etiology and pathogenesis. The
development of breast cancer involves a combination of genetic, hormonal, environmental, and
lifestyle factors that lead to the transformation of normal breast cells into malignant cells.

Etiology of Breast Carcinoma

The etiology of breast carcinoma can be broadly divided into genetic and non-genetic factors:

1. Genetic Factors:
o BRCA1 and BRCA2 Mutations:
▪ Mutations in the BRCA1 and BRCA2 genes are the most well-known
genetic risk factors for breast cancer. Women with these mutations have a
significantly higher risk of developing breast cancer, often at a younger
age.
▪ These genes normally produce proteins that help repair DNA damage,
preventing uncontrolled cell growth. Mutations lead to the loss of this
protective function, increasing the likelihood of malignant transformation.
 o Other Genetic Mutations:
▪ Mutations in other genes such as TP53, PTEN, and PALB2 also increase
breast cancer risk, though they are less common than BRCA mutations.
▪ TP53 mutations are associated with Li-Fraumeni syndrome, a condition
that greatly increases the risk of breast cancer and other cancers.
o Family History:
▪ A strong family history of breast cancer, especially in first-degree
relatives, suggests a genetic predisposition. This history may be due to
known mutations like BRCA1/2 or other hereditary factors not yet fully
understood.
2. Hormonal Factors:
o Estrogen Exposure:
▪ Prolonged exposure to estrogen, whether endogenous (produced by the
body) or exogenous (from hormone replacement therapy), increases the
risk of breast cancer. Estrogen promotes the proliferation of breast tissue,
providing more opportunities for mutations to occur.
▪ Early menarche (onset of menstruation) and late menopause extend the
period of estrogen exposure, increasing breast cancer risk.
o Reproductive History:
▪ Nulliparity (having no children) or having a first child at a late age is
associated with a higher risk of breast cancer. Breastfeeding and having
multiple pregnancies may have a protective effect due to hormonal
changes that reduce overall lifetime estrogen exposure.
3. Environmental and Lifestyle Factors:
o Radiation Exposure:
▪ Exposure to ionizing radiation, especially during puberty or young
adulthood, increases the risk of breast cancer. This is seen in women who
received radiation therapy for conditions like Hodgkin's lymphoma.
o Diet and Obesity:
▪ Obesity, particularly postmenopausal obesity, is a risk factor for breast
cancer. Adipose tissue produces estrogen, which can stimulate breast
tissue proliferation in postmenopausal women.
▪ High-fat diets and alcohol consumption have also been linked to an
increased risk of breast cancer, though the exact mechanisms are not fully
understood.
o Physical Inactivity:
▪ Lack of physical activity is associated with a higher risk of breast cancer,
possibly due to its effects on body weight, insulin sensitivity, and hormone
levels.
4. Other Factors:
o Age:
▪ The risk of breast cancer increases with age, with most cases occurring in
women over 50 years old.
o Ethnicity:
▪ Ethnic background can influence breast cancer risk. For example,
Ashkenazi Jewish women have a higher prevalence of BRCA mutations,
 and African American women are more likely to develop aggressive forms
like triple-negative breast cancer.
o Previous Breast Conditions:
▪ Women with a history of atypical hyperplasia or lobular carcinoma in situ
(LCIS) have an increased risk of developing invasive breast cancer.

Pathogenesis of Breast Carcinoma

The pathogenesis of breast carcinoma involves multiple steps, from the initial genetic and
epigenetic changes in normal breast cells to the development of invasive cancer.

1. Initiation:
o Genetic Mutations:
▪ The pathogenesis often begins with genetic mutations in breast epithelial
cells. Mutations in tumor suppressor genes (e.g., BRCA1, BRCA2, TP53)
or oncogenes (e.g., HER2) can initiate the process of carcinogenesis.
▪ These mutations can be inherited (germline mutations) or acquired during
a person’s lifetime due to environmental factors like radiation or
carcinogens.
o Hormonal Influence:
▪ Estrogen and progesterone play a critical role in the initiation of breast
cancer. Estrogen promotes cell division in breast tissue, increasing the
likelihood of genetic errors during DNA replication.
▪ Hormonal imbalances or prolonged exposure to estrogen without adequate
progesterone can lead to cellular proliferation and mutations.
2. Promotion:
o Cellular Proliferation:
▪ Once initial genetic alterations occur, affected cells begin to proliferate
abnormally. This proliferation is often driven by further hormonal
stimulation or additional mutations.
▪ Dysregulated signaling pathways (e.g., the PI3K/AKT pathway) that
control cell growth and survival are commonly activated in breast cancer.
o Loss of Cell Cycle Control:
▪ Key regulators of the cell cycle, such as p53 and RB1, may be inactivated
in breast cancer cells. This loss of control allows cells to bypass normal
growth checkpoints, leading to unchecked proliferation.
3. Progression:
o Development of Carcinoma In Situ:
▪ The initial stages of breast cancer often manifest as carcinoma in situ,
where abnormal cells are confined to the ducts (ductal carcinoma in situ,
DCIS) or lobules (lobular carcinoma in situ, LCIS) without invading
surrounding tissues.
▪ This stage represents a critical point where the tumor is still localized and
has not yet acquired the ability to invade or metastasize.
o Invasion and Metastasis:
 ▪
Over time, additional genetic changes enable the tumor cells to break
through the basement membrane and invade surrounding breast tissue,
leading to invasive carcinoma.
▪ Tumor cells may acquire the ability to invade lymphatic vessels or blood
vessels, allowing them to spread to regional lymph nodes or distant organs
(metastasis).
▪ The ability to metastasize is facilitated by processes like epithelial-
mesenchymal transition (EMT), where cancer cells gain migratory and
invasive properties.
4. Molecular Alterations:
o HER2 Amplification:
▪ In some breast cancers, the HER2 gene is amplified, leading to
overexpression of the HER2 protein on the cell surface. This drives
aggressive tumor growth and is associated with a poorer prognosis.
o Hormone Receptor Expression:
▪ Hormone receptor-positive breast cancers depend on estrogen and/or
progesterone for growth. These cancers are typically less aggressive and
respond well to hormone therapies like tamoxifen or aromatase inhibitors.
5. Tumor Microenvironment:
o Angiogenesis:
▪ As the tumor grows, it stimulates the formation of new blood vessels
(angiogenesis) to supply nutrients and oxygen. This process is mediated
by factors like vascular endothelial growth factor (VEGF).
o Immune Evasion:
▪ Breast cancer cells may evade the immune system by expressing immune
checkpoint proteins, such as PD-L1, which inhibit the immune response.
This allows the tumor to grow and spread more easily.

7. Etiopathogenesis of Myocardial infarction? Briefly on Lab Diagnosis of MI?

Myocardial infarction (MI), commonly known as a heart attack, occurs when there is a sudden
reduction or cessation of blood flow to a part of the heart muscle, leading to tissue ischemia and
necrosis. The etiology and pathogenesis of MI are closely linked to atherosclerosis and the
formation of a thrombus.

Etiology of Myocardial Infarction

1. Atherosclerosis:
o The most common cause of MI is the rupture or erosion of an atherosclerotic plaque
within a coronary artery.
o Atherosclerosis is characterized by the buildup of lipid-laden plaques in the coronary
arteries. These plaques consist of a core of cholesterol, fatty substances, cellular waste
products, calcium, and fibrin, covered by a fibrous cap.
2. Thrombosis:
 o When an atherosclerotic plaque ruptures, the exposed lipid core and underlying tissue
trigger platelet adhesion, activation, and aggregation at the site of the rupture.
o This leads to the formation of a thrombus (blood clot) that can partially or completely
occlude the coronary artery, drastically reducing or stopping blood flow to the
downstream heart muscle.
3. Coronary Artery Spasm:
o In some cases, a coronary artery spasm, a sudden constriction of the muscles within the
artery wall, can reduce blood flow and lead to MI.
o Spasms can be triggered by factors such as smoking, stress, or drug use (e.g., cocaine).
4. Other Causes:
o Less commonly, MI can be caused by emboli (e.g., thromboembolism from a distant
site), vasculitis (inflammation of the coronary arteries), or coronary dissection (a tear in
the artery wall).

Pathogenesis of Myocardial Infarction

1. Plaque Formation and Instability:

o Atherosclerotic plaques develop over many years due to endothelial injury, which can
be caused by factors like hypertension, hyperlipidemia, smoking, and diabetes.
o The plaque becomes unstable when the fibrous cap is thin or the lipid core is large.
Inflammatory cells within the plaque release enzymes that degrade the fibrous cap,
making it more susceptible to rupture.
2. Plaque Rupture and Thrombus Formation:
o When a plaque ruptures, the contents are exposed to the blood, initiating a cascade of
events involving platelet activation and aggregation.
o The coagulation cascade is also activated, leading to the formation of a fibrin clot that,
along with aggregated platelets, forms a thrombus.
3. Coronary Artery Occlusion:
o The thrombus can occlude the coronary artery, leading to a sudden reduction or
complete cessation of blood flow to the heart muscle (myocardium).
o The extent of myocardial damage depends on the location of the occlusion, the size of
the affected coronary artery, and the duration of the occlusion.
4. Myocardial Ischemia and Necrosis:
o Within minutes of the coronary artery occlusion, the affected myocardial tissue
becomes ischemic due to the lack of oxygen and nutrients.
o If blood flow is not restored quickly, ischemia progresses to irreversible damage, leading
to myocardial necrosis (death of heart muscle cells).
5. Ventricular Remodeling:
o After an MI, the infarcted area undergoes healing with scar tissue formation. The
remaining viable myocardium undergoes remodeling, which can lead to changes in the
size, shape, and function of the heart.
o Adverse remodeling can contribute to heart failure and other complications in the long
term.

Lab Diagnosis of Myocardial Infarction

The laboratory diagnosis of MI involves the detection of specific biomarkers released by the
injured myocardial cells into the bloodstream. These biomarkers, along with clinical history,
electrocardiography (ECG), and imaging studies, are essential for diagnosing MI.

Key Biomarkers for MI Diagnosis:

1. Cardiac Troponins (cTnI and cTnT):

o Troponins are the most specific and sensitive biomarkers for myocardial injury.
o They begin to rise within 3-4 hours after the onset of MI, peak at 12-24 hours, and can
remain elevated for 1-2 weeks.
o An elevated troponin level, particularly when there is a rise and/or fall in levels, is a key
indicator of MI.
2. Creatine Kinase-MB (CK-MB):
o CK-MB is an isoenzyme of creatine kinase found predominantly in heart muscle.
o It rises within 3-6 hours after MI, peaks at 12-24 hours, and returns to normal within 48-
72 hours.
o CK-MB is less specific than troponins but can be useful in diagnosing recurrent MI.
3. Myoglobin:
o Myoglobin is an early marker of muscle injury, including myocardial injury.
o It rises within 1-2 hours after MI, peaks at 6-9 hours, and returns to baseline within 24
hours.
o Due to its lack of specificity for cardiac muscle, it is less commonly used as a sole marker
for MI diagnosis.
4. Other Biomarkers:
o Lactate Dehydrogenase (LDH): LDH levels rise later than CK-MB and troponins and are
less specific.
o B-type Natriuretic Peptide (BNP) or NT-proBNP: These markers are not specific for MI
but can be elevated in heart failure, which often accompanies MI.

8. Define meningitis? Causes of meningitis? Enumerate tuberculous meningitis?

Meningitis is an inflammation of the protective membranes (meninges) covering the brain and
spinal cord. It can be caused by various infectious agents or non-infectious conditions.

Causes of Meningitis

1. Bacterial Meningitis: Caused by bacteria such as:

o Neisseria meningitidis (meningococcus)
o Streptococcus pneumoniae (pneumococcus)
o Haemophilus influenzae type b (Hib)
o Listeria monocytogenes (more common in newborns, elderly, and
immunocompromised individuals)
o Group B Streptococcus (in newborns)
2. Viral Meningitis: Often less severe than bacterial meningitis and caused by viruses such
as:
 o Enteroviruses (e.g., Coxsackievirus, Echovirus)
o Herpes simplex virus (HSV)
o Varicella-zoster virus (VZV)
o Mumps virus
o Measles virus
3. Fungal Meningitis: Caused by fungi such as:
o Cryptococcus neoformans
o Histoplasma capsulatum
o Coccidioides immitis
4. Parasitic Meningitis: Less common, caused by parasites such as:
o Naegleria fowleri (primary amoebic meningoencephalitis)
o Angiostrongylus cantonensis (rat lungworm)
5. Non-Infectious Meningitis: Can be due to:
o Autoimmune diseases (e.g., systemic lupus erythematosus)
o Certain medications
o Cancer (meningeal carcinomatosis)
o Head injury or surgery

Tuberculous Meningitis

Tuberculous meningitis (TB meningitis) is a type of bacterial meningitis caused by

Mycobacterium tuberculosis. It is a severe form of meningitis and is often a complication of
pulmonary tuberculosis. Here are some key points about TB meningitis:

• Symptoms: Gradual onset of symptoms such as headache, fever, neck stiffness, and
altered mental status. It may also present with signs of increased intracranial pressure or
cranial nerve deficits.
• Diagnosis: Often involves a combination of clinical presentation, cerebrospinal fluid
(CSF) analysis, imaging studies (such as MRI or CT), and microbiological tests (e.g.,
acid-fast bacilli smear, culture for Mycobacterium tuberculosis, and polymerase chain
reaction (PCR) tests).
• Treatment: Typically involves a combination of antituberculous medications such as
isoniazid, rifampin, ethambutol, and pyrazinamide, along with corticosteroids to reduce
inflammation.

9. Define and Classify Pneumonia? Write the difference between lobar pneumonia and
Broncho pneumonia.

Pneumonia is an infection that inflames the air sacs (alveoli) in one or both lungs. The alveoli
may fill with fluid or pus, leading to symptoms like cough, fever, chills, and difficulty breathing.

Classification of Pneumonia
Pneumonia can be classified based on various factors, including the causative agent, the setting
of acquisition, and the pattern of lung involvement.

1. Based on Causative Agent:

o Bacterial Pneumonia: Caused by bacteria such as Streptococcus pneumoniae,
Staphylococcus aureus, Haemophilus influenzae, or atypical bacteria like
Mycoplasma pneumoniae and Chlamydophila pneumoniae.
o Viral Pneumonia: Caused by viruses such as influenza, respiratory syncytial
virus (RSV), or coronaviruses.
o Fungal Pneumonia: Caused by fungi like Histoplasma capsulatum or
Coccidioides immitis.
o Parasitic Pneumonia: Caused by parasites like Toxoplasma gondii or
Strongyloides stercoralis.
2. Based on Acquisition Setting:
o Community-Acquired Pneumonia (CAP): Acquired outside of a healthcare
setting.
o Hospital-Acquired Pneumonia (HAP): Acquired during a hospital stay,
typically 48 hours or more after admission.
o Ventilator-Associated Pneumonia (VAP): A type of HAP that occurs in people
who are on mechanical ventilation.
o Healthcare-Associated Pneumonia (HCAP): Acquired in healthcare settings
other than hospitals, such as nursing homes or dialysis centers.
3. Based on Pattern of Lung Involvement:
o Lobar Pneumonia: Affects a specific lobe of the lung.
o Bronchopneumonia: Affects patches throughout both lungs, often involving the
bronchi and surrounding alveoli.
o Interstitial Pneumonia: Involves inflammation of the interstitium (the tissue
surrounding the alveoli) rather than the alveoli themselves.

Differences Between Lobar Pneumonia and Bronchopneumonia

• Lobar Pneumonia:
o Pattern: Typically affects an entire lobe of the lung.
o Etiology: Often caused by Streptococcus pneumoniae.
o Onset: Generally has a sudden onset with severe symptoms.
o Radiographic Appearance: Shows consolidation of a lobe on a chest X-ray.
o Symptoms: Includes high fever, sharp pleuritic chest pain, and a productive
cough with rusty or bloody sputum.
o Course: Usually has a more defined and localized pattern of infection, which can
be more responsive to treatment.
• Bronchopneumonia:
o Pattern: Affects multiple areas throughout both lungs, often in a patchy
distribution, typically involving the bronchi and surrounding alveoli.
o Etiology: Often associated with a range of bacterial pathogens, including
Staphylococcus aureus, Haemophilus influenzae, or Pseudomonas aeruginosa.
o Onset: Often more gradual and can be associated with other underlying
conditions or infections.
o Radiographic Appearance: Shows scattered, patchy infiltrates or consolidations
on a chest X-ray.
o Symptoms: May present with a more generalized set of symptoms, including
cough, fever, and sputum production, but often less intense than lobar pneumonia.
o Course: Can be associated with more diffuse lung involvement and may
complicate or arise from other conditions.
Unit -3

1. Define and classify anemia.

Anemia is when a person have low levels of healthy red blood cells to carry oxygen throughout the body.
Hemoglobin is the main protein in red blood cells. It carries oxygen, and delivers it throughout the body.
If anemia is present hemoglobin level will be low too. If it is low enough, tissues or organs may not get
enough oxygen.

Symptoms of anemia

pale skin

Shortness of breath

Tiredness or weakness

Anemia is divided into three major groups:

• Anemia caused by blood loss

• Anemia caused by decreased or faulty red blood cell production

• Anemia caused by destruction of red blood cells

Anemia is caused through bleeding also and this can happen slowly over a long period of time, and
might not be noticed. Causes can include:

Gastrointestinal conditions such as ulcers, gastritis (inflammation of stomach), and cancer

A woman’s period, especially if heavy menstruation (or heavy period).

Anemia Caused by Destruction of Red Blood Cells : In hemolytic anemia, red blood cells in the blood are
destroyed earlier than normal.

With this type of anemia, body may not create enough blood cells, or they may not work the way they
should. This can happen because there’s something wrong with red blood cells or because not
enough minerals and vitamins for the red blood cells to form normally. Conditions associated with these
causes of anemia include:

Bone marrow problems and stem cell problems (Aplastic anemia and Thalassemia )

Iron-deficiency anemia (t’s the most common form of anemia. It happens when the body doesn’t have
enough iron to make hemoglobin, a substance in red blood cell that allows them to carry oxygen
throughout the body. )

Sickle cell anemia : Sickle cell disease is a group of inherited red blood cell disorders that affect
hemoglobin,

Vitamin-deficiency anemia, specifically b12 or folate (Megaloblastic and Perincious anaemia

2. Define Hematopoiesis? Write different sites & stages of Hematopoiesis. Write a note on extra
medullary hematopoiesis.

The bone marrow is comprised of a myriad of haematopoietic stem cells that promote their
differentiation of mature blood cells. Hematopoiesis is the blood cell production process. Cells that
circulate in blood include immune cells (white blood cells), red blood cells, and platelets.

Therefore, it is necessary that a renewable supply of progenitor cells exists to replace old cells. The
pluripotent stem cells formed during the embryonic period have the capacity to differentiate into
common myeloid progenitor and common lymphoid progenitor cell lineages. Haîma: Blood.Poiēsis: To
make something. Hematopoiesis is also called hemopoiesis, hematogenesis and hemogenesis.

• Extramedullary haematopoiesis (EMH) is defined as the production of blood cells outside of the
bone marrow, which occurs when there is inadequate production of blood cells. Physiologic
EMH occurs during embryonic and fetal development; during this time the main site of fetal
hematopoiesis are liver and the spleen.

• Pathologic EMH can occur during adulthood when physiologic hematopoiesis can't work
properly in the bone marrow and the hematopoietic stem cells (HSC) have to migrate to other
 tissues in order to continue with the formation of blood cellular components. Pathologic EMH
can be caused by myelofibrosis, thalassemias or disorders caused in the hematopoietic system.

3. Define Iron Deficiency anemia? Describe etiology and Laboratory findings in Iron Deficiency
Anemia.

Iron-deficiency anemia is the most common type of anemia. It occurs when the body doesn’t have
enough iron, which the body needs to make hemoglobin. When there isn’t enough iron in blood, the
rest of the body can’t get the amount of oxygen it needs.

Causes or etiology

Blood loss from the gastrointestinal tract due to gastritis (inflammation of the stomach), esophagitis
(inflammation of the esophagus), ulcers in the stomach or bowel

Blood loss from chronic nosebleeds

Blood loss from the kidneys or bladder

Frequent blood donations

Intravascular hemolysis, a condition in which red blood cells break down in the blood stream, releasing
iron that is then lost in the urine.

taking non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and aspirin

lab diagnosis :

Complete blood count (CBC) : In CBC hemoglobin (Hg) hematocrit (Hct) will be low

Serum ferritin : Low ferritin(Ferritin is a blood protein that contains iron.

Serum iron : Low serum iron (FE) Iron to measure the amount of iron in blood.

Transferrin or TIBC : High transferrin or total iron-binding capacity (TIBC) Low iron saturation

The peripheral smear or blood slide may show small, oval-shaped cells with pale centers. In severe iron
deficiency, the white blood count (WBC) may be low

Testing the urine for blood and Testing for blood in the stool sample

4. Define Megaloblastic anemia? Describe Clinical features and Lab Diagnosis of Megaloblastic
anemia.

Megaloblastic anemia is a form of macrocytic anemia. Macrocytic anemia is a blood disorder that causes
bone marrow to make abnormally large red blood cells

Megaloblastic anemia is a condition in which the bone marrow produces unusually large, structurally
abnormal, immature red blood cells (megaloblasts). Megaloblastic anemia is characterized by RBCs that
are larger than normal.

Causes

Gastrectomy:This surgery removes part of stomach, which may affect vitamin B12 absorption.
Zollinger-Ellison syndrome: This rare condition keeps body from absorbing vitamin B12.

Signs and symptoms

• shortness of breath

• muscle weakness

• skin that is paler than usual

• glossitis, or a swollen tongue

• loss of appetite or weight loss

• diarrhea

• nausea

• fast heart rate

Lab diagnosis

• Peripheral Blood Smear: Examination of a peripheral blood smear show the presence of
enlarged, irregular and abnormally shaped red blood cells.
• Bone Marrow Biopsy: Enlarged and immature red blood cells are found in bone marrow and
they confirm the diagnosis.
• blood tests : Serum Cobalamine and Serum Folate
• Serum Methylmalonate and Homocysteine: In patients with cobalamin deficiency, serum
methylmalonate and homocysteine levels are raised.
• Blood tests to detect the antibodies toward intrinsic factor or the cells that produce it.

5. Define Leukocytosis and List its causes.

Leukocytosis is condition which is characterized by increased levels of leukocytes in the blood.

Leukocytosis is most commonly caused by infection or inflammation. Other high white blood cell count
causes may include:

Some of the common causes of neutrophilia include

➢ having spleen removed

➢ a reaction to medications, including steroids, lithium, or certain types of inhalers

A few potential causes of lymphocytosis include:

➢ allergic reactions

➢ certain types of leukemia

➢ viral infections

Some of the main causes of eosinophilia include:

 ➢ allergies and allergic reactions, such as hay fever and asthma

➢ parasitic infections

Possible causes of monocytosis include:

➢ infections caused by the Epstein-Barr virus (including mononucleosis)

➢ tuberculosis

➢ fungal infections

Causes of basophilia include:

➢ leukemia

➢ bone marrow cancer

6. Define and Classify Bleeding disorders. Discuss pathogenesis of Hemophilia.

Bleeding disorders are a group of conditions that result when the blood cannot clot properly. In normal
clotting, platelets, a type of blood cell, stick together and form a plug at the site of an injured blood
vessel. Proteins in the blood called clotting factors then interact to form a fibrin clot,

Classification of bleeding disorders

Hemophilia is a rare, inherited bleeding disorder that can range from mild to severe, depending on how
much clotting factor is present in the blood. Hemophilia is classified as type A or type B, based on which
type of clotting factor is lacking (factor VIII in type A and factor IX in type B). Hemophilia A and B are
both sex-linked disorders that are inherited in an X-linked recessive manner.

Von Willebrand disease is an inherited condition that results when the blood lacks functioning von
Willebrand factor, a protein that helps the blood to clot and also carries another clotting protein, factor
VIII. It is usually milder than hemophilia and can affect both males and females.

Causes :

Hemophilia A

Normally, a gene called F8 carries instructions on how to create factor VIII. Hemophilia A happens when
that gene mutates and becomes an abnormal gene that makes a faulty version of factor VIII or doesn’t
make factor VIII at all. About 70% of people who have hemophilia A inherited the disorder.

Hemophilia B results from insufficient amounts of clotting factor 9.

Normally, a gene called F9 carries instructions on how to create factor 9. Hemophilia B happens when
that gene mutates and becomes an abnormal gene that leads to low factor 9 levels or even missing
factor 9.

Hemophilia C
Normally, the F11 gene carries instructions on how to create factor XI. Hemophilia C happens when that
gene mutates and becomes an abnormal gene. This abnormal gene may not make enough factor XI or
may not make factor XI.

Congenital hemophilia

Hemophilia is usually inherited, meaning a person is born with the disorder (congenital). Congenital
hemophilia is classified by the type of clotting factor that's low.

7. Describe in detail Blood Transfusion reactions.

Transfusion reactions are medical complications that arise after a blood transfusion. They may occur
during the transfusion (known as acute) or weeks after it (delayed).

Acute transfusion reaction

✓ Simple allergic reaction

✓ Febrile non-hemolytic transfusion reaction

✓ Acute hemolytic transfusion reaction

✓ Transfusion-related acute lung injury (TRALI).

Delayed transfusion reaction

✓ Graft versus host disease

Simple allergic reaction

Even when a person receives the correct blood type, allergic reactions can occur. reactions occur due
tothe donor blood containing specific plasma proteins that the recipient’s blood sees as allergens the
donor blood containing food allergens, such as peanut or gluten

Symptoms

Rash itching and hives

Treatment

taking an antihistamine to help treat an allergic reaction

Febrile non-hemolytic transfusion reaction

febrile non-hemolytic transfusion reaction (FNHTR) is the most common reaction. It involves an
unexplained rise in temperature during or 4 hours after the transfusion. The fever is part of the person’s
white blood cells response to the new blood.

Symptoms will depend on the severity and may include:

body temperature higher than 38ºC (100.4ºF)

If FNHTR occurs during the transfusion, the healthcare professional will stop the procedure.
Acute hemolytic transfusion reaction : This type of reaction occurs during, immediately afterward, or
within 24 hours of the transfusion. This type of reaction occurs if a person has received the wrong blood
type. A hemolytic transfusion reaction is a serious complication that can occur after a blood transfusion.
The reaction occurs when the red blood cells that were given during the transfusion are destroyed by
the person's immune system. When red blood cells are destroyed, the process is called hemolysis.

Symptoms can include:

red or brown urine

If a person develops an acute hemolytic transfusion reaction, the doctor or nurse will stop the
transfusion.

Treatment depends on the severity of the reaction and may include: IV fluids

Transfusion-related acute lung injury (TRALI). Occurs when the recipient's lungs are damaged by the
transfused blood. This results in pulmonary edema, or excess fluid in the lungs.

Symptoms : severe shortness of breath

For more severe cases, a person may require artificial ventilation.

Transfusion-associated graft-versus-host disease (ta-GVHD) is a rare and usually fatal complication of

blood transfusion Occurs when the donated blood contains immune cells that attack the recipient's
tissues. Symptoms: rash, diarrhea, and liver damage.

Treatment : These immunosuppressive medicines decrease donor cells’ ability to start an immune
response (attack) against tissues.

8.Describe the components of blood and their indications.

Whole Blood: Whole blood is the most common type of blood component. It is used to treat patients
who have suffered significant blood loss due to trauma, surgery, or other medical conditions.

Red Blood Cells (RBCs): RBCs are used to treat patients with anemia, sickle cell disease, and other
conditions that affect the production of red blood cells in bone marrow Shelf Life: 21/35 days

Platelets: Platelets are used to treat patients with bleeding disorders,

Fresh Frozen Plasma (FFP): Fresh Frozen Plasma (FFP) is prepared from freshly collected blood. On
separation, the plasma is immediately deep frozen and stored. FFP contains all the proteins required for
normal clotting of blood, and is commonly used in clotting factor deficiency usually caused by liver
diseases.

White cell transfusion

successful transfusion of white cells can assist patients to combat infections when, as it sometimes
happens in certain blood diseases, the patients' body is unable to produce its own white cells

Indications of blood transfusions

• Anemia
• Major Surgical Operation
• Accidents resulting in considerable blood loss
• Cancer patients requiring therapy
• Women in childbirth and newborn babies in certain cases
• Patients of hereditary disorders like Haemophilia and Thalassaemia
• Severe burn victims
 Unit -4
1. Write in detail Physical examination of Urine.

Urine is a liquid byproduct of the body secreted by the kidneys through a process called urination
and excreted through the urethra. The normal chemical composition of urine is mainly water
content, but it also includes nitrogenous molecules, such as urea, as well as creatinine and other
metabolic waste components.

Volume : The usual range (healthy persons) for 24-hour urine volume is around 800-2000 ml

• Oliguria : An abnormally small amount of urine, often due to shock or kidney damage.
• Polyuria : An abnormally large amount of urine, often caused by diabetes.

Color :Normal urine is typically light yellow and clear without any cloudiness.

Dehydration (dark urine color)

Liver disease ("bilirubin," a digestive substance secreted by the liver, stains urine a tea or cola color)

Blood in the urine (hematuria visible may indicate urinary tract infection, stones, tumors, or injuries)

Odor of urine : usually it is odourless

Fruity odour : diabetes mellitus

pungent odor. The ammonical odor result is due to break down and conversion of urea in the urine into
ammonia by the action of bacteria.

pH Level : The common value for urine pH is 5.5–7.5

The urine must be tested within a few hours of collection to avoid skewing the results for the pH test, as
urine will become more alkaline as time passes.

A high urine pH may be due to: Kidneys that do not properly remove acids from the bloodstream (renal
tubular acidosis) and Kidney failure

A low urine pH may be due to:

Diabetic ketoacidosis

Turbidity:Normally freshly voided urine is clear. When urine is allowed to stand, amorphous crystals,
usually urates may precipitate and cause urine to be cloudy.

• The turbidity of urine should always be recorded

• Turbid (cloudy) urine may be caused by either normal or abnormal processes. Normal conditions
giving rise to turbid urine include precipitation of crystals, mucus, or vaginal discharge.
Abnormal causes of turbidity include the presence of blood cells, yeast, and bacteria.

Specific Gravity is a simple indicator of how concentrated the urine is. The normal range of specific
gravity in adults is 1 to 1.030.
An increase in this could be an indicator of dehydration, diarrhoea, urinary tract infection, or decrease
blood flow to the kidney.

A decrease in specific gravity could indicate conditions such as renal failure or pyelonephritis

2. What are the abnormal constituents of urine? Describe the Benedict’s test?

• Protein in the urine (proteinuria), mainly albumin

• Glucose (sugar) in the urine (glycosuria)

• Ketones in the urine (ketonuria), products of fat metabolism

• Hemoglobin/blood in the urine (hematuria)

• Leukocyte esterase (suggestive of white blood cells in urine)

• Nitrite (suggestive of bacteria in urine)

• Bilirubin (possible liver disease or red blood cell breakdown)

• Urobilinogen (possible liver disease or etodolac [Lodine] medication)

Casts crystals microorganisms are also the abnormal constituents present in urine

Benedicts test :

Principle : Benedict’s test is performed when the reducing sugar is heated with Benedict‘s reagent. The
copper (II) ions in the Benedict’s solution are reduced to Copper (I) ions, which causes the color change.
The red copper(I) oxide formed is insoluble in water and is precipitated out of solution. This accounts for
the precipitate formed. As the concentration of reducing sugar increases, the nearer the final color is to
brick-red and the greater the precipitate formed.

Procedure :

1. Approximately 1 ml of urine sample is placed into a clean test tube.

2. 2 ml (10 drops) of Benedict’s reagent (CuSO4) is placed in the test tube.

3. The solution is then heated in a boiling water bath for 3-5 minutes.

4. It is Observed for color change

Interpretation is as follows
3. What are the abnormal constituents of urine? Describe the Heat and acetic acid test?

• Protein in the urine (proteinuria), mainly albumin

• Glucose (sugar) in the urine (glycosuria)

• Ketones in the urine (ketonuria), products of fat metabolism

• Hemoglobin/blood in the urine (hematuria)

• Leukocyte esterase (suggestive of white blood cells in urine)

• Nitrite (suggestive of bacteria in urine)

• Bilirubin (possible liver disease or red blood cell breakdown)

• Urobilinogen (possible liver disease or etodolac [Lodine] medication)

Casts crystals microorganisms are also the abnormal constituents present in urine

Heat and acetic acid test

Principle: This test is based on the principle that proteins get precipitated when boiled in an acidic
medium.

Procedure :

5-10ml urine is taken in a test tube.

Boil the upper portion over a flame.

It is Compared with the lower part. Cloudiness or turbidity indicates the presence of proteins

2-4 drops of 10% glacial acetic acid is added and it is again boiled

If turbidity is still present, protein is present in urine.

Result and Interpretation:

Negative : No cloudiness
Trace: Barely visible cloudiness.

1+ : definite cloudy

2+ : heavy cloudy

3+ : densed cloudy

4+ : thick curdy precipitation

4. Write in detail microscopic examination of Urine.

The urine sample is centrifuged at 2500 rpm for 5 minutes and the sediment is observed under the
microscope

• Red blood cells 0-3 is normal

A red blood cell number elevated from the norm can indicate injury, inflammation, disease/infection of
the urinary tract (e.g. bladder/kidneys/urethra).

White blood cells 0-5 is normal

• A white blood cell number elevated from the norm can indicate infection or inflammation of the
urinary tract.

Epithelial Cells 0-3 is normal

• A raised number of epithelial cells from the norm can indicate infections, malignancies and
inflammation of the urinary tract.

Microorganisms-nil

• Yeast: indicates a vaginal yeast infection and requires a follow-up test on vaginal secretions
(swab) to test for fungal infection.

• Bacteria: these can enter the urethra from the exterior and travel up to the bladder causing a
urinary tract infection. If left untreated this can progress to a more serious kidney infection.
Sometimes, the bacteria can originate from inside the body, for instance in the case of
septicaemia where the bacteria has infected the urinary tract from the bloodstream.

• A follow-up urine culture test should be performed where harmful bacteria is found.

Casts : hyaline cast is normal

Casts are Casts are cylindrical, cigar shaped microscopic structures composed mainly of
mucoprotein produced when the kidney cells secrete protein. Usually, these are visibly clear
(hyaline), but various kidney diseases alter their appearance, giving an indicator of which
disorder is present. For example, where red or white blood cell casts are found in the
microscopic examination, a kidney disorder is indicated.

Crystals : Crystals in urine occur when there are too many minerals in urine and not enough liquid. The
tiny pieces collect and form masses. These crystals may be found during urine tests (urinalysis). Having
crystals in urine is called crystalluria.
Normal urine contains a range of different crystals such as calcium oxalates, These ordinary crystals
cause no problem, but abnormal crystals in the urine can cause pain and damage to the urinary tract
such as bilirubin cysteine, tyrosine and leucine. Kidney stones (calculi) form in the kidney and can
become lodged in either the kidney or ureters.

5.What is CSF? Write about functions and collection of CSF?

Cerebrospinal fluid (CSF) is a clear, colorless liquid found in the brain and spinal cord. The brain and
spinal cord make up central nervous system. 70% of the CSF is produced and secreted by the choroid
plexus, in the lateral 3rd and 4th ventricle while the reminder is produced by the surface of brain and
spinal cord CSF is continually produced, circulated, and then absorbed into the blood. About (500 mL)
of CSF are produced each day with around 150 ml being present in the body at any given time.This rate
of production means that all the CSF is replaced every few hours. Cerebrospinal fluid is made by tissue
called the choroid plexus

Functions of CSF

Buoyancy : It provides neutral buoyancy that prevents the brain from compressing the blood vessels and
cranial nerves against the internal surface of the bones of the skull.

Protection : The CSF acts as a shock absorber, by providing a fluid buffer and thus protecting the brain
from injury.

Homeostasis : regulates the distribution of metabolites surrounding the brain, keeping the external
environment stable.

Clearing waste : waste products produced by the brain cells are excreted into the CSF, which then drains
into the bloodstream.

Collection of CSF

A lumbar puncture (spinal tap) is a procedure where a healthcare provider inserts a needle into lower
back to remove a sample of cerebrospinal fluid.

A CSF sample is obtained by a physician usually via lumbar puncture in the L3-L4or L4 or L5 region.
Sterile technique is always used to reduce the risk of infection. Care must be taken to avoid injury to
neural tissue.

Antiseptic is used to sterile the area of puncture

Local anaesthesia is given to the patient through the syringe

A syringe is used to remove 6 - 15 mL of spinal fluid in an adult. However, the opening pressure is first
measured and if it is elevated greater than 200 mm, no more than 2 mL of CSF would be withdrawn.
Less fluid is removed in babies and small children. The CSF sample is divided among 3 - 4 tubes, with 2 -
4 mL in each tube. And then it is transported into the laboratories

Glass tubes should not be used due to cell adhesion, which may affect the cell count or differential.
Sterile containers also can be used.

6. Describe Physical examination of CSF?

Examination of CSF is very important in disease diagnosis

A CSF sample must be processed within 30 to 60 minutes of collection or the cells will deteriorate.

Opening pressure: 70 to 180 mm of water

Specific gravity : 1.006-1.008

Appearance: clear, colorless

Rate of production : 500 ml/day

Total volume : 120-150 ml in adults

Normally microorganisms (bacteria virus fungi parasites ) are absent

Cancerous cells: No cancerous cells present

Cell count: 0 to 5 white blood cells (all mononuclear) and 0 red blood cells

Chloride: 110 to 125 mEq/L (110 to 125 mmol/L)

Glucose: 50 to 80 mg/dL

Lactate dehydrogenase: less than 40 U/L

Protein: 15 to 60 mg/dL (0.15 to 0.6 g/L)

Abnormal Results Mean

If the CSF looks cloudy, it could mean there is an infection or a buildup of white blood cells or protein.

If the CSF looks bloody or red, it may be a sign of bleeding or spinal cord obstruction. If it is brown,
orange, or yellow, it may be a sign of increased CSF protein or previous bleeding (more than 3 days ago).
There may be blood in the sample that came from the spinal tap itself. This makes it harder to interpret
the test results.

CSF PRESSURE

Increased CSF pressure may be due to increased intracranial pressure (pressure within the skull).

Decreased CSF pressure may be due to spinal cord tumor, shock, fainting, or diabetic coma .

CSF PROTEIN

Increased CSF protein may be due to blood in the, tumor, injury, or any inflammatory or infectious
condition.

Decreased protein is a sign of rapid CSF production.

7. Describe collection methods of urine. Write short notes on preservation of urine.

Collection and transportation of urine specimens to the clinical laboratory are important
because variables such as collection method, container, transportation, and storage affect the
analysis outcome and consequently diagnostic and therapeutic decisions based on the results.
 Midstream “clean catch” specimen

• Hands are washed thoroughly with soap and water.

• Male Instructions

• Cleanse the end of the penis with the first soap beginning at the urethral opening and working
away from it .

• Void the first portion of the urine into the toilet.

• While continuing to void, place the collection cup into the midstream to collect the urine
specimen. Do not touch the inside or lip of the cup with the hands or any other part of the
body. Void remainder of the urine into the toilet.

• Replace the cap on the cup touching only the outside surfaces of the cap and cup. Screw the lid
on tightly.

female Instructions

• Stand in a squatting position over the toilet. Separate the folds of skin around the urinary
opening. Cleanse the area around the opening Void the first portion of the urine into the toilet.

• While continuing to void, place the collection cup into the midstream to collect the urine
specimen. Do not touch the inside or tip of the cup with the hands or any other part of the
body. Void remainder of the urine into the toilet.

• Replace the cap on the cup touching only the outside surfaces of the cap and cup. Screw the lid
on tightly.

Routine or random sample : The patient is given a sterile collection container and instructed to
collect a midstream specimen in the container. This type of specimen is routinely used for
urinalysis and may not be used for a culture and sensitivity.

Preservation of Urine Specimen

Urine should be examined immediately as much as possible after it is passed, because some
urinary components are unstable. If urine specimen can not be examined immediately, it must
be refrigerated or preserved by using different chemical preservatives. Long standing of urine at
room temperature can cause

1. Growth of bacteria

2. Break down of urea to ammonia by bacteria leading to an increase in the pH of the urine

3. Lysis of RBCs, WBCs and casts.

• No preservation are required if the urine is examined within 1-2 hours after voiding. If delay is
anticipated, refrigeration at 2-8 *c but not freezed . Preservatives are required for 24-hours
specimen collection. When 24-hours specimen are collected or when a sample is to be mailed to
a distant laboratory for examination, to prevent decomposition and contamination it is
 necessary to added preservatives to the urine. Some of the preservatives include toluene
concentrated hydrochloric acid and sodium carbonate

8. What is Sputum? Describe Sputum examination and its importance.

• Sputum is matter expectorated from the respiratory system (and especially the lungs). It is a
thick mucosy substance contain pus, blood, fibrin, or microorganisms (such as bacteria) in
diseased state

• Sputum is produced when a person’s lungs are diseased or damaged. Sputum is not saliva but
the thick mucus (sometimes called phlegm) which is coughed up from the lungs. Sometimes,
such as when there is an infection in the lungs, an excess of mucus is produced. The body
attempts to get rid of this excess by coughing it up as sputum.

Sputum culture is used to diagnose

➢ Bronchitis (inflammation of the bronchus )

➢ Lung abscess (Pus filled cavity )

➢ Pneumoniae (Pneumonia is an infection that inflames the air sacs in one or both lungs)

➢ Tuberculosis (Tuberculosis (TB) is an infectious disease that most often affects the lungs and is
caused by a type of bacteria

➢ Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease that
causes obstructed airflow in the lungs.

➢ Cystic fibrosis (Cystic fibrosis is a disease that causes thick, sticky mucus to build up in the lungs,
digestive tract, and other areas of the body. )

Sputum is examined for the colour consistency microorganisms and abnormal cells

• Sputum culture: A sputum culture is done in a laboratory to identify the presence and type of
cells in a sputum sample that may cause disease. If a specific bacteria is found, the lab can then
do further tests to figure out which antibiotic is most effective against that bacteria

• Sputum for tuberculosis: A sputum sample may be obtained to look for tuberculosis, though
several samples are often needed in order to find one that is diagnostic (AFB )

• Sputum cytology: In sputum cytology, a sample of sputum is evaluated under the microscope.
This can be done to look for signs of tuberculosis or signs of cancer cells. Sputum cytology is not
a reliable lung cancer screening tool. However, if cancer cells are found, it can be diagnostic of
lung cancer and further tests can determine the location of the cancer.

9. Describe AFB staining for sputum sample.

• In 1882, Paul Ehrlich developed the Acid Fast Staining technique.

• Later, Ziehl and Neelson developed it in 1883 and hence the technique is also called as “Ziehl-
Neelsen Staining Technique”.
 The main aim of this technique was to distinguish bacteria between acid fast groups and non-
acid fast groups.

• Acid-fast organisms are characterized by wax-like nearly impermeable cell wall, containing
mycolic acid along with large amount of fatty acids, waxes, and complex lipids.

• The acid-fast microorganisms are resistant to decolorization by acid due to the composition of
cell wall.

Principle :

• When the bacterial smear is flooded with carbol fuschin (primary stain) in presence of heat, the
stain penetrates in the bacterial cell wall. Due to which bacteria appears red in color. Due to the
presence of mycolic acid and high lipid content, even after decolorization step, the acid fast
bacteria retains the primary stain whereas the non acid fast bacteria gets decolorize.

• When the smear is flooded with methylene blue (counter stain), the decolorized non acid-fast
bacteria takes the counter stain and appears blue in color. Whereas, the acid fast stain bacterial
group cannot taken the counter stain because of the presence carbol fuschin stain in their cell
wall and hence they appear red in color.

Materials required

• Ziehl Neelson Carbol – fuchsin (primary stain).

• Acid Fast Decolourisation (acid alcohol)

• Methylene Blue (secondary stain )

• Bunsen Burner

• Slides

• Inoculating loop

• Sample

Procedure

➢ On a clean sterile microscopic slide, the smear is made The smear is flooded with carbol fuschin
and gently heated until it produces fumes should not boil

➢ It is Allowed to stand for 5 minutes and washed off with gently flowing tap water.

➢ The smear is covered with Acid alcohol for 1 minute

➢ It is Washed off with water.

➢ The smear is flooded with methylene blue dye and left for 1-3 minutes and washed with tap
water.

➢ the smear is air dried examined under the oil immersion microscopy

Interpretation
➢ Acid fast bacteria : Pink

➢ Non-Acid fast bacteria : Blue

 Unit 5:

1. What are the various blood collection methods? Write the Procedure of
Venous blood collection?

Various Blood Collection Methods:

1. Venous Blood Collection: The most common method, where blood is drawn from a
vein, typically in the arm.
2. Capillary Blood Collection: Blood is collected from a capillary bed, usually by pricking
the fingertip or heel.
3. Arterial Blood Collection: Blood is drawn from an artery, often used for blood gas
analysis.
4. Peripheral Blood Collection: Blood is collected from a peripheral vein, often using a
smaller needle.
5. Bone Marrow Aspiration: A sample is taken from the bone marrow, usually for
diagnostic purposes.

Procedure for Venous Blood Collection

1. Preparation:
• Identify the patient: Confirm the patient's identity and explain the procedure.
• Prepare equipment: Gather all necessary materials, including gloves, tourniquet,
antiseptic swab, needle, collection tubes, and gauze.
• Position the patient: Ensure the patient is comfortable, with their arm extended.

2. Site Selection and Cleaning:

• Select a vein: Typically, the median cubital vein is chosen as it is easy to access.
• Apply a tourniquet: Place the tourniquet 3-4 inches above the chosen site to engorge the
vein.
• Clean the site: Use an antiseptic swab to clean the area in a circular motion from inside
out.

3. Blood Collection:

• Insert the needle: With the bevel up, insert the needle at a 15-30 degree angle into the
vein.
 • Fill the collection tubes: Allow the required amount of blood to flow into the collection
tubes.
• Remove the tourniquet: Once blood flow is established, remove the tourniquet.

4. Post-Collection:

• Withdraw the needle: Remove the needle once the required blood is collected.
• Apply pressure: Immediately place gauze over the puncture site and ask the patient to
apply pressure.
• Label the tubes: Label the blood collection tubes with the patient’s details.

5. Aftercare:

• Dispose of the needle: Safely discard the needle in a sharps container.

• Check the patient: Ensure the patient is not feeling dizzy or unwell.
• Provide aftercare instructions: Advise the patient to avoid heavy lifting with the arm
for a short period.

2. What are the different methods of hemoglobin estimation? Describe Sahlis

method in brief?

Different Methods of Hemoglobin Estimation:

1. Sahli’s Method (Acid Hematin Method): A colorimetric method where hemoglobin is

converted to acid hematin and then compared to a color standard.
2. Cyanmethemoglobin Method: Hemoglobin is converted to cyanmethemoglobin and
measured spectrophotometrically.
3. Automated Hematology Analyzers: Uses electrical impedance or light scatter to
estimate hemoglobin.
4. Oxyhemoglobin Method: Measures the absorbance of oxyhemoglobin at specific
wavelengths.
5. Alkaline Hematin D-575 Method: A colorimetric method using alkaline hematin.

Sahli’s Method (Acid Hematin Method) – Brief Description:

Principle:

• Hemoglobin in the blood is converted to acid hematin by adding hydrochloric acid. The
brown color of acid hematin is then compared against a standard color scale to estimate
the hemoglobin concentration.
Procedure:

1. Reagent Preparation: Use 0.1N hydrochloric acid as the reagent.

2. Sample Addition: Place 20 µL of blood into the hemoglobinometer tube containing the
acid.
3. Mixing: Stir until the blood is completely converted to acid hematin.
4. Comparison: Dilute with distilled water until the color matches the standard on the
comparator.
5. Reading: The hemoglobin concentration is read directly from the scale in grams per
deciliter (g/dL).

Cyanmethemoglobin Method for Hemoglobin Estimation

Principle: The Cyanmethemoglobin method (also known as the Drabkin’s

method) is a widely used and standardized technique for estimating hemoglobin
levels. In this method, hemoglobin is converted into a stable compound,
cyanmethemoglobin, which can be measured spectrophotometrically.

Reagents:

• Drabkin’s Reagent: A solution containing potassium ferricyanide, potassium cyanide,

and a non-ionic detergent.

o Potassium ferricyanide oxidizes hemoglobin to methemoglobin.

o Potassium cyanide converts methemoglobin to cyanmethemoglobin.

Equipment:

• Spectrophotometer or colorimeter set at a wavelength of 540 nm.

• Test tubes or cuvettes.
• Pipettes.

Procedure:

Sample Collection:

Collect venous blood using EDTA as an anticoagulant to prevent clotting.

Reagent Preparation:
Drabkin’s reagent should be prepared fresh or used as commercially available. It is pale yellow
in color.

Hemolysis and Conversion:

Add 20 µL of blood to 5 mL of Drabkin’s reagent in a test tube. Mix well.

o The potassium ferricyanide in the reagent oxidizes hemoglobin (Hb) to

methemoglobin.
o Potassium cyanide then converts methemoglobin to cyanmethemoglobin.

Incubation:

o Allow the mixture to stand at room temperature for 5-10 minutes to ensure
complete conversion.

Measurement:

o Measure the absorbance of the cyanmethemoglobin solution at 540 nm using a

spectrophotometer.
o The intensity of the color is directly proportional to the hemoglobin concentration.

Calculation:

o Compare the absorbance to a standard calibration curve prepared using

cyanmethemoglobin standards.
o The hemoglobin concentration is typically expressed in grams per deciliter (g/dL).

3. Describe Westergren method for ESR?

Westergren Method for ESR (Erythrocyte Sedimentation Rate)

Principle: The Westergren method is a standardized technique for measuring the

rate at which red blood cells (erythrocytes) settle in a vertical column of
anticoagulated blood over one hour. The rate of sedimentation is an indirect
measure of the presence of inflammation and can be elevated in various medical
conditions.

Materials:

• Westergren tube (200 mm in length, 2.5 mm in diameter)

 • Westergren pipette stand
• EDTA-anticoagulated venous blood
• 0.85% Sodium Chloride (optional for dilution)
• Timer

Procedure:

Sample Collection:

o Collect venous blood in a tube containing EDTA as an anticoagulant. Blood can

also be diluted with sodium chloride if required.

Filling the Westergren Tube:

o Draw 2 mL of the anticoagulated blood into the Westergren tube using the pipette.
o Ensure no air bubbles are present, as they can interfere with the results.

Positioning the Tube:

o Place the tube vertically in the Westergren stand. The tube should be at room
temperature and free from vibrations or drafts.

Timing:

o Start the timer and allow the blood to stand undisturbed for exactly one hour.

Reading the Result:

o After one hour, measure the distance in millimeters from the top of the blood
column to the top of the settled red cells. This distance is the ESR and is reported
in millimeters per hour (mm/hr).

Interpretation:

• Normal Values:

o Men: 0-15 mm/hr

o Women: 0-20 mm/hr
• Increased ESR: Indicates inflammation, infection, anemia, autoimmune disorders, or
malignancies.
• Decreased ESR: May be seen in polycythemia, sickle cell anemia, and certain protein
abnormalities.
Advantages:

• Sensitivity: Effective in detecting inflammation and monitoring disease progression.

• Simplicity: Easy to perform with minimal equipment.

Disadvantages:

• Non-specificity: Elevated ESR is not specific to any single condition.

• Time-consuming: Requires a full hour to complete the test.

The Westergren method remains a valuable and widely used test for assessing the
presence and severity of inflammatory processes

4. Discuss steps in tissue processing?

Steps in Tissue Processing

Tissue processing is a critical step in histopathology, allowing tissues to be

prepared for microscopic examination. The process involves several steps to
preserve and harden the tissue so it can be sliced thinly for staining and
examination.

1. Fixation:

• Purpose: To preserve the tissue by stabilizing proteins and preventing autolysis and
decay.
• Common Fixative: 10% formalin (neutral buffered formaldehyde) is most commonly
used.
• Procedure: Tissues are immersed in the fixative for a duration that depends on the tissue
type and size, ensuring thorough penetration.

2. Dehydration:

• Purpose: To remove water from the tissue, as embedding media like paraffin wax are not
miscible with water.
• Procedure: Tissue is passed through a series of ascending alcohol concentrations (70%,
80%, 90%, 95%, and 100% ethanol) to gradually dehydrate it.

3. Clearing:

• Purpose: To remove the alcohol and make the tissue transparent, preparing it for
infiltration with embedding medium.
• Common Clearing Agents: Xylene, chloroform, or toluene.
 • Procedure: The tissue is immersed in a clearing agent that is miscible with both alcohol
and paraffin.

4. Infiltration (Impregnation):

• Purpose: To replace the clearing agent with molten paraffin wax, providing support for
cutting thin sections.
• Procedure: The tissue is placed in molten paraffin wax at around 60°C, allowing the wax
to penetrate and support the tissue.

5. Embedding (Blocking):

• Purpose: To embed the tissue in a solid block of paraffin wax, providing a medium for
sectioning.
• Procedure: The tissue is placed in a mold filled with molten paraffin, which is then
allowed to solidify at room temperature, forming a block.

6. Sectioning:
• Purpose: To cut thin slices (sections) of the tissue for microscopic examination.
• Procedure: The paraffin block is mounted on a microtome, and thin sections (usually 4-6
micrometers thick) are cut. These sections are then floated on a warm water bath to
remove wrinkles and picked up on glass slides.

7. Staining:

• Purpose: To enhance contrast and differentiate between different tissue components.

• Common Stains: Hematoxylin and eosin (H&E) is the most common stain used.
• Procedure: The sections are deparaffinized, rehydrated, stained, dehydrated again, and
then mounted with a coverslip for examination.

8. Mounting:

• Purpose: To protect the stained tissue section and make it permanent.

• Procedure: A drop of mounting medium is placed on the stained section, and a coverslip
is applied.

These steps ensure that the tissue is preserved, sectioned, and stained in a way that
allows for detailed microscopic examination, leading to accurate diagnosis.
5. What is DLC? Write the procedure of Leishman staining of blood smear.

Differential Leukocyte Count (DLC)

Definition: The Differential Leukocyte Count (DLC) is a hematological test that

measures the percentage of different types of white blood cells (leukocytes) in the
blood. The five types of leukocytes typically assessed are neutrophils,
lymphocytes, monocytes, eosinophils, and basophils. The DLC is useful in
diagnosing and monitoring various conditions such as infections, inflammations,
and hematological disorders.

Procedure for Leishman Staining of Blood Smear

Purpose: Leishman staining is used to examine blood smears under a microscope

to identify and differentiate blood cells, particularly for performing a DLC.

Materials:

• Glass slide with a thin blood smear

• Leishman stain
• Buffered distilled water (pH 6.8)
• Dropper or pipette
• Timer
• Microscope

Procedure:

Preparation of Blood Smear:

o Place a drop of blood on a clean glass slide.

o Using another slide, spread the blood drop to create a thin, even smear.
o Allow the smear to air-dry completely.

Staining:

o Place the slide on a flat surface and cover the smear with Leishman stain (10–15
drops) using a dropper.
o Allow the stain to stand for 2 minutes to fix the cells.

Dilution and Staining:

 o Add twice the volume of buffered distilled water (about 20–30 drops) to the stain
on the slide.
o Gently mix by rocking the slide to ensure even distribution.
o Allow the diluted stain to act for 7-10 minutes. During this time, the stain will
differentiate the cells.

Washing:

o After staining, gently rinse the slide with buffered water to remove excess stain.
o Allow the slide to air-dry completely without blotting.

Microscopic Examination:

o Once dry, examine the slide under a microscope using oil immersion (100x
objective lens).
o Identify and count different types of white blood cells to perform the DLC.

Results Interpretation:
• Neutrophils: Pink cytoplasm with a multi-lobed nucleus.
• Lymphocytes: Large nucleus with a thin rim of blue cytoplasm.
• Monocytes: Kidney-shaped nucleus with abundant gray-blue cytoplasm.
• Eosinophils: Bright red-orange granules in the cytoplasm.
• Basophils: Dark purple granules in the cytoplasm.

This procedure allows for the detailed examination of blood cells, aiding in the
diagnosis of various hematological conditions.

6. Explain in detail H & E staining.

Hematoxylin and Eosin (H&E) Staining

Purpose: Hematoxylin and Eosin (H&E) staining is the most widely used
technique in histology and pathology for highlighting the general structure of tissue
sections. Hematoxylin stains cell nuclei blue-purple, while Eosin stains the
cytoplasm and extracellular matrix pink. This contrast allows for the differentiation
of tissue components and is essential for diagnosing diseases.

Principle:
 • Hematoxylin: Acts as a basic dye, binding to acidic structures such as nucleic acids,
staining the cell nuclei blue to purple.
• Eosin: Acts as an acidic dye, binding to basic components of the cytoplasm and
extracellular matrix, staining them pink to red.

Procedure for H&E Staining

Materials:

• Fixed and paraffin-embedded tissue sections

• Microtome
• Hematoxylin solution (commonly Mayer’s or Harris’ Hematoxylin)
• Eosin solution (Eosin Y or Eosin B)
• Xylene (for deparaffinization)
• Alcohol series (for rehydration and dehydration)
• Distilled water
• Mounting medium and coverslip

Steps:

Sectioning:

o Use a microtome to cut thin sections (4-6 micrometers thick) from the paraffin-
embedded tissue block.
o Float the sections on a warm water bath to remove wrinkles and then place them
on glass slides.
o Dry the slides to ensure the sections adhere properly.

Deparaffinization:

o Immerse the slides in xylene for 2-3 changes, 5 minutes each, to remove the
paraffin wax.

Rehydration:

o Pass the slides through a series of descending alcohol concentrations (100%, 95%,
80%, and 70% ethanol) for 2 minutes each.
 o Rinse briefly in distilled water to complete the rehydration process.

Hematoxylin Staining:

o Immerse the slides in hematoxylin for 5-10 minutes (time may vary depending on
the formulation).
o Rinse the slides in tap water until the water runs clear.
o Differentiate the staining by dipping the slides briefly in a 1% acid alcohol
solution (1% HCl in 70% ethanol) if needed.
o Rinse again in tap water to stop differentiation.
o Blue the sections by immersing them in an alkaline solution, such as Scott’s tap
water or lithium carbonate, to achieve a crisp blue color in the nuclei.

Eosin Staining:

o Immerse the slides in Eosin solution for 1-3 minutes.

o Rinse briefly in distilled water to remove excess eosin.

Dehydration:

o Pass the slides through a series of ascending alcohol concentrations (70%, 80%,
95%, 100% ethanol) for 2 minutes each to dehydrate the tissue.
o Clear the slides in xylene for 2-3 changes, 5 minutes each.

Mounting:

o Apply a drop of mounting medium on the tissue section and carefully place a
coverslip on top.
o Allow the slides to dry completely.

Results Interpretation:

• Nuclei: Blue to purple, indicating areas rich in DNA and RNA.

• Cytoplasm: Pink, highlighting proteins and other basic components.
• Collagen fibers: Pink, allowing differentiation from muscle fibers and other structures.
• Red Blood Cells: Bright red due to their affinity for eosin.

Advantages:

• Contrast: Provides clear differentiation between the nucleus and cytoplasm.

• Universality: Applicable to a wide range of tissues, making it a standard in
histopathology.
Disadvantages:

• Non-specificity: Does not provide information on specific molecules or proteins.

• Fading: Stains may fade over time, especially if exposed to light.

7. Explain in detail about RBC count?

Red Blood Cell (RBC) Count

Definition: The RBC count measures the number of red blood cells (erythrocytes)
in a given volume of blood. RBCs are crucial for transporting oxygen from the
lungs to the rest of the body and returning carbon dioxide to the lungs for
exhalation. The RBC count is an important parameter in diagnosing and
monitoring various hematological conditions.

Normal Values:

• Men: 4.5 - 5.9 million cells/µL

• Women: 4.0 - 5.2 million cells/µL
• Children: 4.1 - 5.5 million cells/µL

Purpose:

• Diagnosing Anemia: A low RBC count can indicate anemia, leading to symptoms like
fatigue and weakness.
• Monitoring Conditions: Useful in monitoring disorders like polycythemia vera
(elevated RBC count) and chronic anemia.
• Evaluating Treatment: Helps assess the effectiveness of treatments for conditions
affecting RBC production.

Procedure for RBC Counting:

1. Sample Collection:

• Collect venous blood using an EDTA tube to prevent clotting.

• 2. Dilution:

• Mix a small volume of blood with an isotonic diluting fluid (e.g., Hayem’s solution or
Gower’s solution) in a pipette. The dilution ratio is usually 1:200.
 • The diluting fluid prevents RBCs from clumping and makes them easier to count.

3. Counting Chamber (Hemocytometer) Preparation:

• Charge the hemocytometer by carefully placing a drop of the diluted blood onto the
counting chamber. Cover with a coverslip.
• Allow the RBCs to settle evenly in the counting grid.

4. Counting:

• Using a microscope, count the RBCs in the five large squares of the hemocytometer’s
grid (four corners and the center square).
• Ensure that only cells completely within the grid or touching the top and left boundaries
are counted to avoid double counting.

5. Calculation:

• Calculate the RBC count using the formula:

RBC Count(cells/µL)= (Number of squares counted×dilution factor)
Number of squares counted×volume of each squar
⚫ For example, if 100 RBCs are counted in the five squares, with a dilution factor of 200 and
each square having a volume of 0.004mm³:
RBC Count=100×200=1,000,000 cells/µL
5X0.004

Clinical Significance:

1. Low RBC Count (Erythropenia):

• Causes: Anemia, blood loss, bone marrow failure, chronic kidney disease, malnutrition,
and some cancers.
• Symptoms: Fatigue, weakness, shortness of breath, and pallor.

2. High RBC Count (Polycythemia):

• Causes: Polycythemia vera, chronic lung disease, high altitude adaptation, dehydration.
• Symptoms: Headaches, dizziness, blurred vision, and risk of clotting.
8. Expand FNAC? Write the procedure of PAP stain.
FNAC stands for Fine Needle Aspiration Cytology. It is a diagnostic procedure
used to investigate lumps or masses in the body. In this procedure, a thin, hollow
needle is inserted into the lump, and a small sample of cells is aspirated (suctioned)
for examination under a microscope.

Procedure of PAP Stain (Papanicolaou Stain)

Purpose: The Papanicolaou (PAP) stain is a multichromatic staining method used

primarily for the cytological examination of exfoliated cells, particularly in the
detection of cervical cancer and precancerous lesions. It is also used in various
other cytological examinations.

Principle: PAP staining differentiates cells based on their staining properties. It

uses a combination of acidic and basic dyes to highlight cell nuclei, cytoplasm, and
other cellular components in different colors.

Materials:

• Fixative (95% ethanol)

• Hematoxylin stain
• OG-6 (Orange G) stain
• EA-50 or EA-65 (Eosin Azure) stain
• Distilled water
• Xylene
• Ethanol (70%, 80%, 95%, 100%)
• Mounting medium and coverslip

Procedure:

Sample Preparation:

o Collect cells using a brush or spatula from the cervix (or other sites for non-
gynecological samples).
o Spread the collected cells evenly onto a glass slide.
o Immediately fix the slide by immersing it in 95% ethanol or spraying it with a
cytological fixative to preserve cellular details.

Hematoxylin Staining:
 ▪ Immerse the slide in Harris or Gill's hematoxylin for 3-5 minutes.
▪ Rinse in distilled water.
▪ Differentiate in 0.5% acid alcohol (1% HCl in 70% ethanol) for a few
seconds to remove excess stain.
▪ Rinse in distilled water and then "blue" the slide in a weak alkaline
solution (e.g., Scott’s tap water).

OG-6 Staining:

▪ Stain the slide with OG-6 for 1.5-2 minutes.

▪ Rinse in 95% ethanol.
▪ OG-6 stains keratinized cells orange.

EA-50 or EA-65 Staining:

▪ Stain the slide with EA-50 or EA-65 for 2-3 minutes.

▪ Rinse in 95% ethanol.
▪ EA stains provide polychromatic colors, where Eosin Y stains the
cytoplasm pink, and light green SF stains non-keratinized cells greenish-
blue.

Dehydration:

o Pass the slide through 95% ethanol followed by 100% ethanol to remove water.
o Clear the slide in xylene for 2-3 changes to remove ethanol.

Mounting:
o Place a drop of mounting medium on the stained slide and cover it with a
coverslip.
o Allow the slide to dry thoroughly.

Results Interpretation:

• Nuclei: Stained blue by hematoxylin.

• Cytoplasm:

o Superficial cells: Stained pink or orange by Eosin and OG-6.

o Intermediate and parabasal cells: Stained blue-green by light green SF.

Applications:
 • Primarily used in cervical cancer screening (Pap smear).
• Also used in diagnosing other malignancies and infections in various body fluids.

The PAP stain remains a cornerstone in cytological diagnostics due to its ability to
provide clear differentiation of cell types and identification of pathological
changes.