HUMAN ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY (LECTURE)

➢ Upper Respiratory Tract NOSE

o Nose - Divided into external nose and internal nasal
o Nasal cavity cavity
o Paranasal sinuses o External nose:
o Pharynx ▪ Superiorly: nasal and frontal
➢ Lower Respiratory Tract bones
o Larynx ▪ Laterally: maxillary bones
o Trachea ▪ Inferiorly: plates of hyaline
o Bronchial tree cartilage
o Lungs o Nasal cavity lies posterior to the external
nose
▪ Air enters the cavity through the
external nares / nostrils (hairs)
• Gas exchange ▪ Divided in the midline by: nasal
o Major function is to supply the body with septum
oxygen and dispose carbon dioxide - The nasal cavity is formed by the following
o Processes of Respiration structures
▪ Pulmonary ventilation: o Roof: ethmoid bone, sphenoid bone,
movement of air into and out of frontal bone
the lungs o Flood: hard palate
▪ External respiration: gas o Laterally: conchae or turbinates which
exchange protrude medially forming grooves
▪ Transport of respiratory gases: inferior to each concha called meatus
oxygen and carbon dioxide must o Medially: nasal septum which is formed
be transported to and from the anteriorly by hyaline cartilage and
lungs and tissues of the body posteriorly by the vomer bone and
▪ Internal respiration: at the perpendicular plate of ethmoid
systemic capillaries, gas
exchanges must be made Paranasal Sinuses
between the blood and tissue - air filled spaces inside the bones that surround
cells the nose
• Regulation of pH - Helps air get warm and moist
o Expelling carbon dioxide - Amplify the sound of your voice
o High pH – alkaline
o Low pH – acidic PHARYNX
o Lungs and kidneys help in controlling the - Serves as a common pathway for food and air
pH of the body - Extends from the base of the skull to the level of
• Voice production C6
• Olfaction - 3 regions:
• Innate immunity o Nasopharynx: serves only as air
passageway (pharyngeal tonsils or
adenoid are located)
o Oropharynx: both swallowed food and
inhaled air pass through it
➢ Conducting zones o Laryngopharynx: common passageway
o Respiratory passages extending from the for food and air
nose to the terminal bronchioles
➢ Respiratory zones
o Actual sites of gas exchange, composed
of the respiratory bronchioles, alveolar
ducts, and alveoli
 HUMAN ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY (LECTURE)

BRONCHI AND SUBDIVISIONS: BRONCHIAL TREE

- right and left bronchi are formed by the division
of the trachea at the level of the sternal angle

LARYNX
- Extends 5cm from the level of the 4th to 6th
cervical vertebra Right Primary Bronchus Left Primary Bronchus
- Superiorly attaches to the hyoid bone and open Diameter Wider Narrower
to the laryngopharynx; inferiorly it is continuous Length Shorter Longer
with the trachea Direction More Vertical Oblique
- Paired cartilages - Bronchioles – air passages under 1 mm in
o Arytenoids: anchor the vocal cords to the diameter and the tiniest of these are the
larynx terminal bronchioles with 0.5cm in diameter
o Cuneiform: found in the aryepiglottic
fold
o Corniculate: found at the apices of
arytenoid Respiratory bronchioles
- Unpaired cartilages - Branch into alveolar sacs and alveoli, the
o Thyroid cartilage: shield shaped with chambers where the bulk of gas exchange occurs
ridge like laryngeal prominence which - Alveoli – minute expansions along the walls of
seen externally as the Adam’s apple the alveolar sacs
o Corticoid cartilage: signet ring shaped - Alveolar wall has no cilia or smooth muscle
cartilage below the thyroid cartilage
o Epiglottis: spoon shaped cartilage and
the only elastic cartilage among the
laryngeal cartilages ➢ Type I pneumocytes – the walls of the alveoli
▪ Prevents food from entering the composed of simple squamous epithelium
laryngeal cavity ➢ Type II pneumocytes – scattered amidst the type
▪ “guardian of the airways” I and secrete a fluid containing surfactant that
coats the gas exposed alveolar surfaces.
Vocal Cords ➢ Alveolar macrophages – provides primary line of
- Vibrate and produce sounds as air rushes defense against inhaled dust, bacteria and other
upward from the lungs foreign particles
- Superior to the true vocal cords are the
vestibular folds or false vocal cords
LUNGS
- Soft, spongy, elastic organs, each weighing 0.5kg
- Paired lungs occupy the entire thoracic cavity
except for the mediastinum
- Each is suspended in its pleural cavity via its root,
and has a base, apex and medial and costal
surfaces
- Hilus – found in the medial surface of each lung
through which blood vessels of the pulmonary
and systemic circulation enter and leave the
lungs

Right Lung vs Left Lung

Right Lung Left Lung
Lobes 3 2
Fissures 1 horizontal
1 oblique
Oblique fissures 1 oblique
Cardiac notch (-) (+)
Lingula (-) (+)

TRACHEA Blood supply in Lungs

- Also called as the wind pipe which is about 10- 1. Pulmonary arteries: delivers blood that is to be
12cm long and 2.5cm in diameter oxygenated
- Reinforced internally by 16-20 C-shaped rings of 2. Pulmonary veins: delivers freshly oxygenated
hyaline cartilage blood from the respiratory zones to the heart
 HUMAN ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY (LECTURE)

3. Bronchial arteries: oxygen rich blood supply that

nourish the lung tissue which arise from the
aorta

PLEURA
- A thin, double layered serosa
o Parietal pleura: lines the thoracic wall
and superior aspect of the diaphragm
o Visceral pleura: cover the external lung
surface, dipping into and lining its
fissures
- Produces pleural fluid
- Pleurisy – inflammation of the pleura and caused
by a decreased secretion of pleural fluid

➢ Inspiration: air is flowing into the lungs (active

phase)
➢ Expiration: air is flowing out of the lungs (passive
phase)
- Refer to the amount of air that is flushed in and
A. Pressure Relationship in the Thoracic Cavity
out of the lungs that varies substantially on the
- Gases travel from an area of higher pressure to
conditions of inspiration and expiration
an area of lower pressure
- Spirometer: used for the measurement of lung
o Intrapulmonary pressure: pressure
volumes and capacities
within the alveoli of the lungs
o Intrapleural pressure: pressure within
the pleural cavity PULMONARY VOLUMES
➢ Tidal volume TV (500mL): volume of air inspired
B. Pulmonary Ventilation: Inspiration and Expiration or expired with each breath
- A completely mechanical process that depends ➢ Inspiratory reserve volume IRV (3000mL):
on volume changes occurring in the thoracic amount of air that can be inspired forcefully after
cavity inspiration of the resting tidal volume
➢ Expiratory reserve volume ERV (1100mL):
amount of air that can be expired forcefully after
expiration of the resting tidal volume
➢ Residual volume RV (1200mL): volume of air still
remaining in the respiratory passages and lungs
after a maximum expiration

PULMONARY CAPACITIES
➢ Functional residual capacity (2300mL): ERV + RV
➢ Inspiratory capacity (3500mL): TV + IRV
➢ Vital capacity (4600mL): IRV + TV + ERV
➢ Total lung capacity (5800mL): ERV + IRV + RV +
TV

1. External Respiration: Pulmonary gas exchange

o Partial pressure gradients and gas
solubility: partial pressure of oxygen in
pulmonary blood is much lower than the
alveoli, resulting to rapid diffusion of
oxygen from the alveoli into the
pulmonary capillary bed
o Thickness of the respiratory membrane:
in healthy lungs, membrane is only 0.5 1
um thick
o Surface area: alveolar surface when
spread flat will cover around 140 square
meters
o Ventilation: perfusion coupling
2. Internal respiration: capillary gas exchange in
body tissues
 HUMAN ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY (LECTURE)

o Partial pressure of oxygen in the tissues Changes in carbon dioxide levels are the most
is always lower than that of the systemic important stimuli affecting respiratory rhythm and
Chemical
depth. Carbon dioxide acts directly on the medulla
arterial blood Factors
via its effect on reducing the pH of blood and
o Oxygen moves rapidly from the blood brainstem tissue.
into the tissues until equilibrium is
reached, and carbon dioxide moves SOUND MECHANISM
quickly along its partial pressure Vesicular breath sounds are soft and low
gradient into the blood pitched with a rustling quality during
Vesicular-Normal
inspiration and are even softer during
expiration.
Fine crackles are brief. discontinuous,
popping lung sounds that are high-pitched.
Crackles-Fine Fine crackles are also similar to the sound of
(Rales) wood burning in a fireplace. or hook and
loop fasteners being pulled apart or
cellophane being crumpled.
Coarse crackles are discontinuous, brief,
popping lung sounds. Compared to fine
Crackles-Coarse
crackles they are louder, lower in pitch and
(Rales)
last longer. They have also been described
as a bubbling sound.
Wheezes are adventitious lung sounds that
are continuous with a musical quality.
Wheezes can be high or low pitched. High
Wheeze
pitched wheezes may have an auscultation
➢ Oxygen transport sound similar to squeaking. Lower pitched
wheezes have a snoring or moaning quality
o Oxyhemoglobin: oxygen and
Low pitched wheezes (rhonchi) are
hemoglobin in combination and is the continuous, both inspiratory and expiratory,
major transport form of oxygen Rhonchi-Low
low pitched adventitious lung sounds that
Pitched Wheezes
➢ Carbon dioxide transport are similar to wheezes. They often have a
o Carbaminohemoglobin: bound to snoring, gurgling or rattle-like quality.
Brochial sounds are hollow, tubular sounds
hemoglobin of rbc (20-30%)
that are lower pitched. They can be
o As a bicarbonate ion in plasma: largest Bronchial
auscultated over the trachea where they are
fraction of carbon dioxide (60-70%) considered normal.
DESCRIPTION FUNCTION Pleural rubs are discontinuous or
Part of face centered above Nostrils provide entrance to nasal continuous, creaking or grating sounds. The
mouth, in and below space cavity; internal hairs begin to filter Pleural Rubs sound has been described as similar to
between eyes incoming air walking on fresh snow or a leather-on-
Conducts air to pharynx; mucous leather type of sound.
Hollow space behind nose lining filters, warms, and moistens Inspiration to expiration periods are equal
incoming air these are normal sounds in the mid-chest
Bronchovesicular
Hollow spaces in certain Reduce weight of skull; serve as area or in the posterior chest between the
skull bones resonant chambers scapula.
Passageway for air moving from
Chamber behind nasal
nasal cavity to larynx and for food
cavity, oral cavity, and
moving from oral cavity to
larynx
esophagus
MOVEMENT MECHANISM AND RESULT
Passageway for air; prevents
Enlargement at top of Taking a deep breath, closing glottis, and forcing
foreign objects from entering
trachea air superiorly from lungs against glottis. Then,
trachea; houses vocal cords
Cough glottis opens suddenly, and a blast of air rushes
Passageway for air; mucous lining
Flexible tube that connects upward. Coughs act to clear the lower
continues to filter particles from
larynx with bronchial tree respiratory passageways.
incoming air
Similar to a cough, except that expelled air is
Conducts air from trachea to
Branched tubes that lead directed through nasal cavities instead of
alveoli; mucous lining continues to
from trachea to alveoli through oral cavity. The uvula, a dangling tag of
filter incoming air
Sneeze tissue hanging from the soft palate, becomes
Contain air passages, alveoli, blood
Soft, cone-shaped organs depressed and closes oral cavity off from
vessels, connective tissues,
that occupy a large portion pharynx, routing air through nasal cavities.
lymphatic vessels, and nerves of
of the thoracic cavity Sneezes clear upper respiratory passages.
the lower respiratory tract
Inspiration followed by release of air in a
Crying number of short expirations. Primarily an
emotionally induced mechanism.
Essentially same as crying in terms of the air
Neural centers for control of respiratory rhythm are Laughing movements produced. Also an emotionally
in the medulla and pons. The medulla is the induced response.
Nervous respiratory rate "pacemaker." Reflex arcs initiated Sudden inspirations resulting from spasms of
Control by stretch receptors in the lungs also play a role in diaphragm: initiated by irritation of diaphragm
respiration by notifying neural centers of excessive Hiccups or phrenic nerves, which serve diaphragm. The
over inflation sound occurs when inspired air hits vocal folds
Increased body temperature, exercise, speech, of closed glottis.
Physical
singing, and non-respiratory air movements modify Very deep inspiration, taken with jaws wide
Factors
both rate and depth of breathing. open; ventilates all alveoli (some alveoli may
Yawn
To a degree, breathing may be consciously remain collapsed during normal quiet
Volition breathing).
controlled if it does not interfere with homeostasis.
Emotional Some emotional stimuli can modify breathing
Factors Examples are fear, anger, and excitement
 HUMAN ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY (LECTURE)

PATTERN MECHANISM
Apnea Absence of breathing
Eupnea Normal breathing
Only able to breathe comfortable in upright
position (such as sitting in chair), unable to
Orthopnea breath laying down, attacks of severe
shortness of breath that wakes a person
from sleep.
Paroxysmal
Nocturnal Increased depth of breathing.
Dyspnea
Increased rate (A) or depth (B), or
Hyperpnea
combination of both
Decreased rate (A) or depth (B), or some
Hyperventilation
combination of both.
Increased frequency without blood gas
Hypoventilation
abnormality
Increased rate and depth of breathing over
a prolonged period of time. In response to
Tachypnea metabolic acidosis, the body's attempt to
blow off CO2, to buffer a fixed acid such as
ketones. Ketoacidosis is seen in diabetics.
Gradual increase in volume and frequency.
Kussmaul’s followed by a gradual decrease in volume
Respiration and frequency. with apnea periods of 10-30
seconds between cycle.
Cheyne-Strokes
Described as a crescendo-decrescendo
Respirations
pattern.
(CSR)

- Acid base imbalance is an abnormality of the

human body's normal balance of acids and bases
that causes the plasma pH to deviate out of the
normal range (7.35 to 7.45)
- Respiratory acidosis – Too much intake of CO2
- Respiratory alkalosis – Excess loss of CO2
- Metabolic acidosis – Excess hydrogen ion
- Metabolic alkalosis – Excess hydrogen ion loss
or excess alkaline intake

➢ Emphysema
o a progressive, degenerative disease that
destroys alveolar walls.
o clusters of small air sacs merge to form
larger chambers, which drastically
decreases the surface area of the
respiratory membrane and thereby
reduces the volume of gases that can be
exchanged through the membrane.
➢ Chronic Bronchitis
o the mucosa of the lower respiratory
passages becomes severely inflamed
and produces excessive mucus.
o pooled mucus impairs ventilation and
gas exchange and dramatically increases
the risk of lung infections, including
pneumonias.
➢ Lung cancer
o Associated with smoking and the most
prevalent type of malignancy
o Continuous irritation prompts the
production of more mucus, but smoking
slows the movements of cilia that clear
this mucus and depresses lung
macrophages.