FEDERAL STATE BUDGETARY EDUCATIONAL INSTITUTION OF HIGHER EDUCATION «PRIVOLZHSKY RESEARCH MEDICAL

UNIVERSITY» OF THE MINISTRY OF HEALTH OF THE RUSSIAN FEDERATION “PRMU”

Faculty of Pharmacy
Department of General Pathology

REPORT ON “PITUITARY GLAND”

Made by: Wiam AHARCHAOU & Jihane SEDJARI

Group : 370A
PREFACE:

● Introduction to endocrine system

● Overview of the pituitary gland
● Hormones produced by the anterior pituitary
● Hormones produced by the posterior pituitary
● Regulation of pituitary hormones
● Functions of pituitary hormones
● Disorders related to the pituitary gland
● Conclusion

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 INTRODUCTION TO ENDOCRINE SYSTEM:

Definition:

The endocrine system is a complex network of glands and organs that produce
and release hormones, which are chemical messengers that regulate various
physiological functions in the body. Unlike the nervous system, which uses
electrical impulses for rapid communication, the endocrine system utilizes
hormones to transmit signals over longer distances through the bloodstream.

Key Components of the Endocrine System:

● Glands: Specialized organs that produce and secrete hormones. Examples

include the pituitary gland, thyroid gland, adrenal glands, pancreas, and
reproductive glands (ovaries and testes).
● Hormones: Chemical messengers that travel through the bloodstream to
target cells or organs, where they exert their effects. Hormones help
regulate processes such as growth and development, metabolism, immune
function, and reproductive functions.

Major Glands in the Endocrine System:

● Hypothalamus: Located in the brain, it produces releasing and inhibiting

hormones that control the pituitary gland.
● Pituitary Gland: Often referred to as the "master gland," it secretes a
variety of hormones that regulate other endocrine glands and influence
numerous bodily functions.
● Thyroid Gland: Found in the neck, it produces hormones that regulate
metabolism and energy balance.
● Adrenal Glands: Situated on top of the kidneys, they release hormones
involved in the body's response to stress, metabolism, and electrolyte
balance.
● Pancreas: Functions as both an endocrine and exocrine gland. The
endocrine portion secretes insulin and glucagon, which regulate blood
sugar levels.

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 ● Reproductive Glands (Ovaries and Testes): Produce sex hormones
(estrogen and progesterone in females, testosterone in males) that
influence sexual development and reproduction.

Regulation of the Endocrine System:

The endocrine system is intricately regulated to maintain balance within the

body. Feedback loops, involving sensors and control centers, help ensure that
hormone levels remain within a narrow range. The hypothalamus and pituitary
gland play crucial roles in orchestrating this regulation.

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Comparison between the endocrine system and the nervous system:

Endocrine system Nervous system

Nature of Uses chemical messengers called Uses electrical impulses and

communication hormones, which are produced by neurotransmitters for rapid,
glands and released into the specific, and short-term
bloodstream. Hormones travel communication. Nerve impulses
throughout the body, affecting travel along neurons and are
target cells and organs. transmitted across synapses to
target cells.

Speed of Generally slower response due to Rapid response, with effects

response the time it takes for hormones to occurring in milliseconds to
travel through the bloodstream. seconds. Nerve impulses travel
Effects may take minutes to hours quickly along neural pathways.
to manifest.

Duration of Longer-lasting effects. Hormones Shorter duration of effects. Nerve

response can have sustained effects over an impulses result in immediate, but
extended period, and their actions often transient, changes in cellular
may persist for hours to days. activity.

Mode of Systemic transmission - hormones Point-to-point transmission - nerve

transmission affect cells throughout the body impulses travel along specific
but only impact target cells with pathways and affect specific target
specific receptors. cells at synapses.

Components Composed of glands such as the Composed of the brain, spinal cord,
pituitary gland, thyroid gland, and nerves. Neurons are the
adrenal glands, and pancreas, primary functional units.
which secrete hormones.

Response to Responds to internal and external Primarily involved in rapid

stimuli stimuli, often related to changes in responses to external stimuli, such
the internal environment or stress. as sensory input or immediate
environmental changes

Examples of Hypothalamus and pituitary gland Brain and spinal cord serve as
Control Centers act as key control centers, central control centers,
regulating hormone secretion. coordinating neural responses.

Specificity of Specificity is determined by the Specificity is determined by the

Target Cells presence of hormone receptors on neural pathways and the presence
target cells. of neurotransmitter receptors on
target cells.

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OVERVIEW OF THE PITUITARY GLAND:

Definition:

The pituitary gland, also known as the hypophysis, is a small, pea-sized gland located at
the base of the brain within a bony cavity called the sella turcica. As a crucial component
of the endocrine system, the pituitary gland plays a central role in regulating various
physiological processes by producing and releasing hormones that influence growth,
metabolism, stress response, reproduction, and other essential functions. The pituitary
gland is often referred to as the "master gland" because of its control over other
endocrine glands throughout the body.

How does the pituitary gland affect other organs and glands?

The hormones the pituitary gland releases have effects on many parts of the body,
especially:

● Thyroid.
● Reproductive system organs, including the ovaries and testes.
● Adrenal glands.

Size and shape of the pituitary gland:

The pituitary gland is a relatively small organ in terms of size, measuring about the size
of a pea. On average, its dimensions are approximately 1 centimeter (0.4 inches) in
diameter. Despite its modest size, the pituitary gland is a powerful regulator of various
physiological functions through the hormones it produces and releases. In terms of
shape, the pituitary gland is often described as having two lobes: the anterior pituitary
(adenohypophysis) and the posterior pituitary (neurohypophysis).

Structure of the pituitary gland:

The pituitary gland is divided into two main lobes: the anterior pituitary
(adenohypophysis) and the posterior pituitary (neurohypophysis). Each lobe has distinct
anatomical and functional characteristics.

1) Anterior Pituitary (Adenohypophysis):

● Composition: The anterior pituitary is composed of glandular tissue and is
derived from embryonic tissue.
● Control: The release of hormones from the anterior pituitary is regulated by

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 releasing and inhibiting hormones from the hypothalamus.
● Blood Supply: The anterior pituitary receives blood from the superior and
inferior hypophyseal arteries.

2) Posterior Pituitary (Neurohypophysis):

● Composition: The posterior pituitary is composed of neural tissue and is an
extension of the hypothalamus.
● Control: Hormones produced by the posterior pituitary are synthesized in the
hypothalamus, transported down nerve fibers, and released when stimulated.
● Storage: The posterior pituitary stores and releases hormones produced by the
hypothalamus, acting as a reservoir for these neurohormones.
● Blood Supply: The posterior pituitary is also supplied by the hypophyseal
arteries.

Connection between the Anterior and Posterior Pituitary:

Both lobes are connected by a thin, funnel-shaped structure called the infundibulum of
pituitary stalk.

The infundibulum serves as a conduit for the passage of nerve fibers and blood vessels
between the hypothalamus and the posterior pituitary.

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HORMONES PRODUCED BY THE ANTERIOR PITUITARY:

The anterior pituitary, also known as the adenohypophysis, produces and releases
several important hormones that play crucial roles in regulating various physiological
processes. Here are the hormones produced by the anterior pituitary:

1) Growth Hormone (GH):

● Function: Stimulates growth, cell reproduction, and regeneration.
● Target Organs: Acts on bones, muscles, and other tissues to promote growth.
2) Prolactin (PRL):
● Function: Stimulates milk production in the mammary glands (lactation).
● Target Organs: Mammary glands in the breasts.
3) Thyroid-Stimulating Hormone (TSH):
● Function: Regulates the production and release of thyroid hormones
(thyroxine and triiodothyronine) from the thyroid gland.
● Target Organ: Thyroid gland.
4) Adrenocorticotropic Hormone (ACTH):
● Function: Stimulates the adrenal glands to produce and release cortisol, a
stress hormone.
● Target Organ: Adrenal cortex of the adrenal glands.
5) Follicle-Stimulating Hormone (FSH):
● Function: Regulates the growth and maturation of ovarian follicles in
females and sperm production in males.
● Target Organs: Ovaries in females and testes in males.
6) Luteinizing Hormone (LH):
● Function: Stimulates ovulation in females and the production of sex
hormones (progesterone and testosterone).
● Target Organs: Ovaries in females and testes in males.

HORMONES PRODUCED BY THE POSTERIOR PITUITARY:

The posterior pituitary, also known as the neurohypophysis, does not produce hormones
itself. Instead, it stores and releases hormones produced by the hypothalamus. The two
main hormones released by the posterior pituitary are:

1) Antidiuretic Hormone (ADH or Vasopressin):

● Function: Regulates water balance by influencing water

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 reabsorption in the kidneys.
● Target Organs: Kidneys.
2) Oxytocin:
● Function: Stimulates uterine contractions during childbirth,
promotes milk ejection during breastfeeding, and has roles in social
bonding and emotional behaviors.
● Target Organs: Uterus and mammary glands.

These hormones are synthesized in the hypothalamus and transported down nerve
fibers, stored in the nerve endings of the posterior pituitary, and released into the
bloodstream when stimulated. The release of these hormones is often in response to
signals such as changes in blood osmolarity for ADH or the mechanical stimulus of
childbirth for oxytocin. The posterior pituitary acts as a storage and release site for these
neurohormones, and their functions are vital for maintaining water balance,
reproductive processes, and certain aspects of social behavior.

REGULATION OF PITUITARY HORMONES:

Role of hypothalamus :

The hypothalamus plays a central and crucial role in regulating the hormones produced
by the pituitary gland. It acts as a control center for the endocrine system, orchestrating
the release of hormones from both the anterior and posterior pituitary lobes. Here are
the key aspects of the hypothalamus' role in regulating pituitary hormones:

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1. Synthesis and Release of Hypothalamic Hormones:

● The hypothalamus synthesizes and releases various regulatory hormones, often

referred to as hypothalamic-releasing hormones or hypothalamic-inhibiting
hormones.
● These hormones travel through a network of blood vessels known as the
hypothalamic-pituitary portal system, which directly connects the hypothalamus
to the anterior pituitary.

2. Control of Anterior Pituitary Hormones:

● The hypothalamic-releasing hormones influence the secretion of specific

hormones from the anterior pituitary.
● For example:
○ Thyrotropin-Releasing Hormone (TRH): Stimulates the release of
Thyroid-Stimulating Hormone (TSH).
○ Corticotropin-Releasing Hormone (CRH): Stimulates the release of
Adrenocorticotropic Hormone (ACTH).
○ Growth Hormone-Releasing Hormone (GHRH): Stimulates the release of
Growth Hormone (GH).
○ Prolactin-Releasing Hormone (PRH): Stimulates the release of Prolactin
(PRL).
● Hypothalamic-inhibiting hormones, such as somatostatin, inhibit the release of
specific hormones like growth hormone.

3. Control of Posterior Pituitary Hormones:

● The hypothalamus produces oxytocin and antidiuretic hormone (ADH or

vasopressin), which are stored in the nerve endings of the posterior pituitary.
● These hormones are released in response to signals from the hypothalamus, such
as changes in blood osmolarity for ADH or the mechanical stimulus of childbirth
for oxytocin.

4. Negative Feedback Mechanisms:

● The hypothalamus is sensitive to feedback signals from the bloodstream, allowing

it to adjust hormone release based on the body's needs.
● When hormone levels reach a certain threshold, negative feedback mechanisms
signal the hypothalamus to decrease the release of hypothalamic-releasing

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 hormones, thereby reducing pituitary hormone secretion.

5. Coordination of Endocrine Response:

● The hypothalamus acts as a coordinator, integrating signals from various parts of

the body to ensure a harmonious endocrine response.
● It plays a crucial role in coordinating the body's response to stress, regulating
metabolism, controlling water balance, and influencing reproductive processes.

Other Factors influencing hormone release

1. Circadian Rhythms: Many hormones released by the pituitary gland, such as growth
hormone and cortisol, follow circadian rhythms. Their release is influenced by the
body's internal clock, with peak levels occurring at specific times of the day or night.

2. Stress: Stressful situations trigger the release of stress hormones, such as cortisol,
from the adrenal glands. The hypothalamus and pituitary are involved in the stress
response, releasing hormones that stimulate the adrenal glands. Adrenocorticotropic
Hormone (ACTH) from the pituitary is particularly involved in this process.

3. Physiological Changes: Changes in physiological conditions, such as dehydration or

changes in blood osmolarity, can influence the release of antidiuretic hormone (ADH)
from the posterior pituitary. ADH helps regulate water balance by affecting water
reabsorption in the kidneys.

4. Metabolic Factors: Metabolic factors, including blood glucose levels, can influence
the release of insulin from the pancreas. While insulin is not directly produced by the
pituitary, it exemplifies how hormones from different glands can interact to maintain
homeostasis.

5. Gonadal Hormones: Gonadal hormones, such as estrogen and testosterone, exert

feedback on the release of gonadotropins (FSH and LH) from the anterior pituitary.
This feedback is crucial for the regulation of reproductive processes.

6. External Stimuli: External stimuli, such as physical stress, exercise, and changes in
environmental conditions, can influence hormone release. For example, increased
physical activity can stimulate the release of growth hormone.

7. Hormone Receptor Sensitivity: The sensitivity of target tissues to pituitary

hormones also plays a role. If target tissues become less responsive to a particular

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 hormone, the pituitary may increase its production to maintain the desired
physiological effect.

FUNCTIONS OF PITUITARY HORMONES:

The pituitary gland is often referred to as the "master gland" because it plays a crucial
role in regulating various bodily functions through the release of different hormones.
Here are the functions of some of the major hormones produced by the pituitary gland:

1. Growth Hormone (GH): GH promotes growth and development in children and

adolescents. It also helps regulate metabolism, body composition, and muscle and bone
growth in adults.

2. Thyroid-Stimulating Hormone (TSH): TSH stimulates the thyroid gland to produce

and release thyroid hormones, which are essential for regulating metabolism, growth,
and development.

3. Adrenocorticotropic Hormone (ACTH): ACTH stimulates the adrenal glands to

produce and release cortisol, a hormone involved in stress response, metabolism, and
immune function.

4. Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH): FSH and LH

are gonadotropins that regulate reproductive development during puberty.

5. Prolactin (PRL): PRL stimulates the development of mammary glands in females,

preparing them for milk production during pregnancy. PRL plays a key role in initiating
and maintaining lactation (milk production) after childbirth.

6. Adrenocorticotropic Hormone (ACTH): ACTH stimulates the adrenal cortex to

produce and release cortisol. Cortisol is involved in various physiological processes,
including metabolism and immune response, which indirectly influence growth and
development.

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Disorders related to the pituitary gland:
1. Hypopituitarism:
Description Insufficient production of one or more pituitary hormones.

Types Isolated pituitary deficiency: One pituitary hormone is

affected and lacking.
Multiple pituitary hormone deficiency: Two or more pituitary
hormones are affected and lacking.
Panhypopituitarism: All pituitary hormones are affected and
lacking.

Causes Tumors, trauma, radiation, autoimmune diseases, and

genetic factors.

Symptoms Depends on the deficient hormone(s) and may include

fatigue, weight loss, infertility, low blood pressure, and
abnormalities in growth.

Clinical Evaluation Assessing symptoms such as fatigue, weight loss, menstrual

irregularities, and signs of hormonal deficiencies.

Hormone Level • Thyroid Hormones: TSH, free T4, T3.

Measurements • Adrenal Hormones: ACTH, cortisol.
• Reproductive Hormones: FSH, LH, estrogen (in females),
testosterone (in males).
• Growth Hormone: IGF-1, GH.

Dynamic Function Tests • Insulin Tolerance Test (ITT).

• Growth Hormone Stimulation Tests.

Imaging Studies • MRI of the pituitary gland to identify structural

abnormalities.
• CT scans may also be used.

Treatment method Hormone Replacement Therapy: Replacement of deficient

hormones, such as thyroid hormones, cortisol, sex hormones,
and growth hormone.
Individualized Treatment: Tailoring therapy based on the
specific hormonal deficiencies identified.

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 2. Hyperpituitarism:
Description Excessive production of one or more pituitary hormones.

Causes Tumors (often benign adenomas), genetic factors.

Symptoms Vary depending on the hormone involved but may include

changes in body shape, weight gain, hypertension, and
metabolic disturbances.

Examples Acromegaly: Excess growth hormone in adulthood, leading to

enlarged bones and tissues.
Cushing's Disease: Excess adrenocorticotropic hormone
(ACTH), causing overproduction of cortisol by the adrenal
glands.
Hyperthyroidism: benign pituitary adenoma causes the thyroid
to release too much thyroid stimulating hormone (TSH) into the
bloodstream, it may develop hyperthyroidism.
Prolactinoma: benign tumor on the pituitary gland, it can cause
too much prolactin to be released into the blood.

Clinical Evaluation Identifying symptoms related to hormone excess, such as

acromegaly, Cushing's disease, or hyperprolactinemia.

Hormone Level • GH, IGF-1 (for acromegaly).

Measurements • ACTH, cortisol (for Cushing's disease).
• Prolactin (for hyperprolactinemia).

Imaging Studies MRI to visualize tumors or abnormalities.

Treatment method Acromegaly: Somatostatin analogs, growth hormone

receptor antagonists, and dopamine agonists.
Cushing's Disease: Surgery to remove the pituitary tumor
(transsphenoidal surgery), medications like cortisol-lowering
drugs, and sometimes radiation therapy.
Prolactinoma: Medication to reduce prolactin levels and
potentially shrink the tumor is usually the first recommended
treatment.

Surgery People with acromegaly or Cushing’s syndrome may undergo a

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 surgical procedure called a transsphenoidal adenomectomy.

3. Pituitary Tumors:
Description Abnormal growths in the pituitary gland, which can be
noncancerous (adenomas) or, rarely, cancerous.

Incidence Common, but often benign and may not cause symptoms.

Symptoms Depends on the size and location of the tumor and may
include headaches, vision problems, hormonal imbalances,
and neurological symptoms.

Imaging Studies • MRI is the preferred method for visualizing pituitary

tumors. Contrast agents may be used for enhanced
visualization.
• CT scans may be used when MRI is contraindicated.

Associations: 1. Multiple endocrine neoplasia type 4.

2. Carney complex.
3. X-LAG syndrome.
4. Succinate dehydrogenase-related familial pituitary
adenoma.

Observation Small, asymptomatic tumors may be monitored without

immediate intervention.

Medication Dopamine agonists for prolactinomas, somatostatin analogs

for certain tumors.

Surgery Transsphenoidal surgery to remove tumors.

Radiation Therapy Used in cases where surgery is not possible or as adjuvant

therapy.

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 4. Pituitary Apoplexy:

Description Sudden hemorrhage or infarction (loss of blood supply) in

the pituitary gland, often associated with pre-existing
tumors.

Symptoms Sudden onset of severe headache, visual disturbances,

hormonal imbalances, and, in severe cases, neurological
symptoms.

Imaging Studies ● MRI is the preferred method for visualizing pituitary

tumors. Contrast agents may be used for enhanced
visualization.
● CT scans may be used when MRI is contraindicated.

Emergency Treatment High-dose corticosteroids to reduce inflammation.

Surgery Urgent transsphenoidal surgery if there is evidence of optic

nerve compression or if medical therapy is insufficient.

5. Diabetes Insipidus:
Description Insufficient production of antidiuretic hormone (ADH),
leading to excessive urine production and thirst.

Causes Tumors, trauma, infections, and sometimes unknown causes.

Symptoms Frequent urination, excessive thirst, dehydration, and

electrolyte imbalances.

Water Deprivation Test Measures the body's response to dehydration to assess ADH
function.

Vasopressin Challenge Test Administering synthetic vasopressin and monitoring urine

output.

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 Hormone Replacement Desmopressin, a synthetic form of vasopressin, to replace
deficient antidiuretic hormone (ADH).

Management of Underlying Treating the underlying conditions causing diabetes insipidus,

Causes such as tumors or trauma.

6. Syndrome of Inappropriate Antidiuretic Hormone (SIADH):

Description Excessive production of ADH, leading to water retention
and dilutional hyponatremia.

Causes Tumors, lung diseases, central nervous system disorders,

and certain medications.

Symptoms Fluid retention, low sodium levels, nausea, headache, and,

in severe cases, seizures.

Blood and Urine Tests Sodium levels, osmolality, and urine sodium concentration.
Fluid restriction test.

Fluid Restriction Limiting fluid intake to help correct hyponatremia.

Medications Demeclocycline or vaptans to counteract the effects of

excess ADH.

Treatment of Underlying Addressing the underlying conditions triggering SIADH.

Causes

7. Sheehan's Syndrome:
Description Pituitary infarction (loss of blood supply) following severe
postpartum hemorrhage.

Symptoms Failure to lactate, amenorrhea, fatigue, and other

symptoms of hypopituitarism.

Clinical Evaluation History of severe postpartum hemorrhage and failure to

lactate.

Hormone level Assessing deficiencies in various pituitary hormones.

Measurements

Imaging Studies MRI to assess the pituitary gland.

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 Hormone Replacement Replacement of deficient hormones, often including thyroid
Therapy
hormones, cortisol, and sex hormones.

Lifestyle Modifications Managing symptoms through lifestyle changes and

medications.

CONCLUSION:

In conclusion, the pituitary gland plays a crucial role in the regulation of various bodily
functions and hormone production. However, like any other organ, the pituitary gland is
susceptible to diseases that can disrupt its normal function.

Throughout this report, we have explored the various diseases associated with the
pituitary gland, including pituitary adenomas, hypopituitarism, and hyperpituitarism,
among others. These diseases can arise from genetic factors, tumors, traumatic injuries,
or even certain medications.

It is evident that these diseases can have a significant impact on an individual's overall
health and quality of life. Proper diagnosis and treatment modalities are essential for
managing these conditions effectively. The use of imaging technologies, hormone level
assessments, and clinical evaluations are critical in identifying pituitary gland diseases
and formulating appropriate treatment plans.

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