all about pituitary gland and its disease

1. GOOD
MORNING

2. BY-
KUNJAN BHORALI
2020/BBT/0011

3. •In vertebrate anatomy the pituitary gland, or
hypophysis, is an endocrine gland about the size
of a pea and weighing 0.5 g (0.02 oz.).
•It is a protrusion off the bottom of the
hypothalamus at the base of the brain, and rests
in a small, bony cavity (sella turcica) covered by
a dural fold (diaphragm sellae).
•The pituitary fossa, in which the pituitary gland
sits, is situated in the sphenoid bone in the
middle cranial fossa at the base of the brain.
•The pituitary gland secretes hormones
regulating homeostasis, including tropic
hormones that stimulate other endocrine glands.
•It is functionally connected to the hypothalamus
by the median eminence via a small tube called
the Pituitary Stalk.
•It is considered to be the "master gland".
Introduction of Pituitary Gland.

4. Origin and location of Pituitary Gland:
•The pituitary gland is also called The
Hypophysis, is the smallest endocrine
gland.
•Hypophysis (meaning undergrowth) is so
named because of its location below the
brain as undergrowth.
•This is an unpaired small ovoid gland
and is no longer than the end of the little
finger.
•It is located at the base of the brain and
lies below the diencephalon in a
depression of basis phenoid bone of the
skull called Sella Turcica.
•It is a complex structure formed of
ectodermic growth of the mouth cavity
and down growth of the infandibulum.

5. PARTS PITUITARY GLAND
Pituitary gland is divided into 3 parts:
PITUITARY GLAND
Pars Intermedia Posterior pituitary
(Neurohypophysis)
Anterior pituitary
(Adenohypophysis)

6. STRUCTURE
Its is very small –
only the size of a
pea, 500mg
LOCATION
Sits just beneath the base of
the brain, behind the bridge
of the nose or,
lies in the hypophyseal fossa
of the sphenoid bone below
the hypothalamus.
Posterior
Pituitary Gland

7. Posterior pituitary(Neurohypophysis):
The posterior pituitary (or neurohypophysis) comprises the posterior lobe of the pituitary
gland and is part of the endocrine system. Despite its name, the posterior pituitary gland is
not a gland, per se; rather, it is largely a collection of axonal projections from the
hypothalamus that terminate behind the anterior pituitary gland.
Anatomy:
The posterior pituitary consists mainly of neuronal projections (axons) extending from the
supraoptic and paraventricular nuclei of the hypothalamus. These axons release peptide
hormones into the capillaries of the hypophyseal circulation. In addition to axons, the
posterior pituitary also contains pituicytes, specialized glial cells resembling astrocytes.
Classification of the posterior pituitary varies, but most sources include the three regions
below:
•Pars nervosa Also called the neural lobe or posterior lobe, this region constitutes the
majority of the posterior pituitary, and is sometimes (incorrectly) considered synonymous
with it. Notable features include Herring bodies and pituicytes.
•Infundibular stalk Also known as the infundibulum or pituitary stalk, the infundibularstalk
bridges the hypothalamic and hypophyseal systems.

8. Oxytoxin
(OT)
(ADH)
Uterus Mammary
gland
Effects
Uterine contraction;
lactation
Kidneys or
Arterioles
Effects
a) Stimulates water retention
b)raises blood pressure by
contracting arterioles
c) induces male aggression
(Antidiuretic Hormones))
Vasopressin
Target in
The Body
Hormone
Secreted
Target in
The Body

9. Pars Intermedia:
•Pars intermedia is the boundary between the anterior and posterior lobes
of the pituitary.
•It contains three types of cells - basophils, chromophobes, and colloid-filled cysts.
•In human fetal life, this area produces melanocyte stimulating hormone or MSH
which causes the release of melanin pigment in skin melanocytes (pigment cells).
•However, the pars intermedia is normally either very small or entirely
absent in adulthood.
In lower vertebrates (fish, amphibians) MSH from the pars intermedia is
responsible for darkening of the skin, often in response to changes in background
color.
This color change is due to MSH stimulating the dispersion of melanin pigment in
dermal (skin) melanophore cells.
Major hormone secreted:
•Melanocyte Stimulating Hormone or MSH

10. Anterior Pituitary Gland
LOCATION
The anterior pituitary
gland is the front lobe of
the pituitary gland,
which is found at the
floor of the brain, called
the sellaturcica
STRUCTURE
It is of the size of a
pea.

11. Anterior pituitary (Adenohypophysis):
•A major organ of the endocrine system, the anterior pituitary, also called the
adenohypophysis, is the glandular, anterior lobe of the pituitary gland.
•The anterior pituitary regulates several physiological processes including
stress, growth, and reproduction.
•Its regulatory functions are achieved through the secretion of various peptide
hormones that act on target organs including the adrenal gland, liver, bone,
thyroid gland, and gonads.
•The anterior pituitary itself is regulated by the hypothalamus and by negative
feedback from these target organs.
•Disorders of the anterior pituitary are generally classified by the presence of
over- or underproduction of pituitary hormones.
•For example, a prolactinoma is a pituitary adenoma that overproduces
prolactin.
•In Sheehan's syndrome of postpartum hypopituitarism, the anterior pituitary
uniformly malfunctions and underproduces all hormones.
•Proper function of the anterior pituitary and of the organs it regulates can
often be ascertained via blood tests that measure hormone levels.

12. Anatomy
The pituitary gland is a pea-sized gland that sits in a protective bony enclosure called the
sella turcica. It is composed of three lobes: anterior, intermediate, and posterior. In many
animals, these three lobes are distinct. However, in humans, the intermediate lobe is but a
few cell layers thick and indistinct; as a result, it is often considered part of the anterior
pituitary. In all animals, the fleshy, glandular anterior pituitary is distinct from the neural
composition of the posterior pituitary.
The anterior pituitary is composed of multiple parts:
•Pars distalis The pars distalis, or "distal part",
comprises the majority of the anterior pituitary
and is where the bulk of pituitary hormone
production occurs. Occasionally, "pars distalis"
is incorrectly used as a synonym for the anterior
pituitary.
•Pars tuberalis The pars tuberalis, or "tubular
part", forms a sheath extending up from the pars
distalis and wrapping around the pituitary stalk.
Its function is poorly understood.
•Pars intermedia The pars intermedia, or
"intermediate part", sits between the pars distalis
and the posterior pituitary and is often very
small in humans.

13. Hormone released by Anterior
Pituitary Gland
ANTERIOR
PITUITARY
TARGET TISSUE
GH Most tissues
TSH Thyroid gland
ACTH Adrenal cortex
Prolactin Breast
FSH Ovaries and testes
LH Ovaries and testes

15. Growth hormone (GH)
• Stimulates the growth of bones,muscle,and other
organ by increasing protein synthesis.
• affects protein, fat and carbohydrate metabolism.
• Too little growth hormone secretion can be the result
of abnormal development of the pituitary gland.
• Release is stimulated by GHRH
• Suppression is by GHRIH

16. Thyroid stimulating hormone (TSH)
• Stimulated by Thyroidtropin-releasing hormone
(TRH )from hypothalamus
• Inhibit by Somatostatin from hypothalamus
• Stimulate the thyroid gland to secrete hormone
thyroxin
• Stimulates growth and activity of the thyroid gland
• When too much TSH is secreted,it cause the thyroid
gland to enlarge and secrete too much thyroxin

17. Adrenocorticotropic hormone
(corticotrophin,ACTH)
• Stimulated by Corticotropin-releasing
hormone(CRH) from the hypothalamus
• ACTH stimulate the adrenal gland(cortex) to secret a
hormone call glucocorticoids.
• Secretion is regulated by negative feedback
(Suppressed when blood level ACTH raises )

18. Prolactin
• Also known as lactogenic hormone
• Stimulated by Prolactin-releasing hormone (PRH)
from hypothalamus
• Inhibit by Dopamin from hypothalamus
• Target cell is mammary gland
• Stimulates the production of milk in the breast
following pregnancy.
• Negative feedback when blood level prolactin increase
• Prolactin hypersecretion in males cause erectile
dysfunction.

19. Gonadotrophins
1) LUTENIZING HORMONE (LH) –
 stimulated by gonadotropin
releasing hormone(GnRH) from
hypothalamus
In males, stimulates the testes to secrete
testosterone
In females, stimulates the release of ovum by ovary.
After ovulation, it stimulate the formation of
corpus luteum in ovary and secret hormone
progesterone

20. 2) FOLLICLE-STIMULATING HORMONE
(FSH)
 in male,stimulate production of sperm cells in
the testes.
 in females, stimulates maturation of ovarian
follicle and secrete estrogen by ovaries

21. DISORDERS OF PITUITARY GLAND
Common Pituitary Disorders:
Pituitary Tumors
Growth Hormone Deficiency
Hypopituitarism
Empty Sella Syndrome
Rare Pituitary Disorders:
Cushing’s Disease
Diabetes Insipidus
Nelson’s Syndrome
Acromegaly and Gigantism
Kallman’s Syndrome

22. Examples of Common Pituitary Disorders:
•Pituitary Tumors: May be hormone-secreting or non-secreting; most are benign; may
cause visual disturbances and headaches as they grow and compress surrounding tissues;
often results in excessive amounts of one pituitary hormone and decreases in others.
Signs and symptoms: Pituitary tumors may manifest with signs and symptoms
related to pituitary hypofunction, specific hormone(s) hypersecretion, and/or mass
effect. Impingement on the chiasm or its branches by a pituitary tumor may result in
visual field defects; the most common is bitemporal hemianopsia Lateral extension of
the pituitary mass to the cavernous sinuses may result in diplopia, ptosis, or altered
facial sensation.Among the cranial nerves, the third nerve is the most commonly
affected. There is no specific headache pattern associated with pituitary tumors and,
in some patients, the headache is unrelated to pituitary adenoma.
Treatment:The goals for treatment of a pituitary tumor include reduction or
complete removal of the tumor, elimination of mass effect, if present,
normalization of hormone hypersecretion, and restoration of normal pituitary
function. Some patients, especially those with large tumors, may require
several therapeutic modalities, including medical, surgical, and radiation
therapies

23. •Growth hormone deficiency: The effects of growth
hormone deficiency vary depending on the age at which they
occur. In children, growth failure and short stature are the
major manifestations of GH deficiency, with common causes
including genetic conditions and congenital malformations.
It can also cause delayed sexual maturity. In adults,
deficiency is rare,with the most common cause a pituitary
adenoma, and others including a continuation of a childhood
problem, other structural lesions or trauma, and very rarely
idiopathic GHD
Treatment: With exogenous GH is indicated only in limited circumstances and
needs regular monitoring due to the frequency and severity of side-effects
•Hypopituitarism: from a variety of causes including tumors, trauma, decreased
pituitary blood supply, infection, sarcoidosis, an autoimmune process, radiation, surgical
removal of the pituitary, or a side effect of pituitary surgery; results in a general decrease
in pituitary hormone production.
Treatment:Treatment of hypopituitarism is threefold: removing the underlying
causes treating the hormone deficiencies, and addressing any other repercussions
that arise from the hormone deficiencies

24. Empty Sella Syndrome : In empty sella syndrome, the sella
turcica (the bony structure at the base of the brain that houses
the pituitary gland) enlarges, but the pituitary remains normal-
sized or shrinks.People with empty sella syndrome have a
defect in the tissue barrier that normally keeps the cerebrospinal
fluid around the brain separate from the sella turcica. As a
result, cerebrospinal fluid puts increased turcia. pressure on the
pituitary gland and the walls of the sella The sella turcica may
enlarge, and the pituitary gland may shrink. Empty sella
syndrome occurs most often in middle-aged women who are
overweight and who have high blood pressure. Less commonly,
the condition occurs after pituitary surgery, radiation therapy, or
infarction (death) of a pituitary tumour.
Symptoms: The empty sella syndrome may produce no symptoms at all and
seldom produces serious symptoms. About half of those affected have headaches, and
some people have high blood pressure as well. In rare cases, there is leaking of the
cerebrospinal fluid from the nose or problems with vision.
Treatment: Unless the syndrome results in other medical problems, treatment for
endocrine dysfunction associated with pituitary malfunction is symptomatic and
supportive. In some cases, surgery may be needed.

25. Examples of Rare Pituitary Disorders:
• Acromegaly and Gigantism: Excess growth hormone
production, usually due to a tumor; when it occurs in childhood, it
causes gigantism associated with excessive bone growth and
abnormally tall stature; in adults, it causes acromegaly, with
increases in bone thickness, coarsened facial features, enlarged hands
and feet, carpal tunnel syndrome, headaches, sweating, sleep apnea,
fatigue, and hypertension.
Treatment:
Stopping or reducing the overproduction of growth
hormone is not easy; thus, doctors may need to use a
combination of surgery, radiation therapy, and drug therapy.
Example:Vikas Kumar "Vicky" Uppal (1986 – June 30,
2007) was a native and resident of India, said to be his
country's tallest man until his death.
On 12 January 2004, The Tribune reported him to be 8 ft
3 in (2.51 m) tall and still growing, being in his late
teens. On 10 June 2005, rediff.com reported him to be 8
ft 10 in (2.69 m) tall.

26. •Cushing’s Disease: Cushing’s syndrome symptoms
caused by a pituitary tumor that produces excess ACTH and
leads to excess exposure to the adrenal gland hormone
cortisol;
symptoms vary but include: upper body obesity, a
rounded face, thin skin, pink streaks on the abdomen,
muscular weakness, osteoporosis, high blood sugar,
and high blood pressure
Treatment :depends on whether the problem is in the adrenal glands, the pituitary
gland, or elsewhere. Surgery or radiation therapy may be needed to remove or
destroy a pituitary tumor. Tumors of the adrenal gland (usually adenomas) can often
be removed surgically. Both adrenal glands may have to be removed if these
treatments are not effective or if no tumor is present.
•Diabetes Incipidus: Central diabetes insipidus is a lack of antidiuretic
hormone that causes excessive production of very dilute urine (polyuria).
Central diabetes insipidus has several causes, including a brain tumor, tuberculosis,
a brain injury or surgery, and some forms of other diseases. The main symptoms are
excessive thirst and excessive urine production. The diagnosis is based on urine tests,
blood tests, and a water deprivation test. People with central diabetes insipidus usually
are given the drugs vasopressin or desmopressin as a nasal spray.

27. Treatment: Vasopressin or desmopressin (a modified form of vasopressin) may
be taken as a nasal spray several times a day. The dose is adjusted to maintain the
body's water balance and a normal urine output. Taking too much of these drugs can
lead to fluid retention, swelling, and other problems
•Nelson’s Syndrome: May result when both adrenal glands
are removed as part of the treatment for Cushing’s Disease; a
pituitary tumor develops that produces ACTH.
Symptoms: Cause darkening of the skin due to
increased production of melanocyte stimulating hormone
(MSH) disturbances, and delayed growth.
Treatment: Pituitary surgery is performed in some cases.
The risk can also be minimized by pituitary irradiation.
•Kallman’s Syndrome: Deficient release of GnRH (gonadotropin-releasing
hormone) leads to lack of FSH and LH production; causes delayed or absent puberty;
associated with no sense of smell; occurs only in males.

28. SUMMARY