The document discusses the pituitary gland and pituitary diseases. It begins by providing an overview of the pituitary gland, noting that it is located at the base of the brain and controls other endocrine glands by releasing hormones into the bloodstream. It then discusses specific pituitary diseases including anterior and posterior pituitary hypofunction, as well as pituitary hyperfunction. Anterior pituitary hypofunction can be caused by tumors, vascular issues, or trauma/infection and results in hormone deficiencies. Posterior pituitary hypofunction impacts antidiuretic hormone and causes diabetes insipidus. Pituitary hyperfunction includes excess secretion of hormones like prolactin, growth hormone, ACTH, and TSH, leading to conditions such as acromegaly, Cushing

1. Pituitary Gland
diseases
SMS 3023
Dr. Mohanad R. Alwan

2. Endocrine Glands
• Controls many body functions
– exerts control by releasing special chemical substances
into the blood called Hormones
– Hormones affect other endocrine glands or body
systems
• Ductless glands
• Secrete hormones directly into bloodstream
– Hormones are quickly distributed by bloodstream
throughout the body

3. Hormones
• Chemicals produced by endocrine glands.
• Act on target organs elsewhere in body.
• Control/coordinate widespread processes:
• Homeostasis.
• Reproduction.
• Growth & Development.
• Metabolism.
• Response to stress.
• Overlaps with the Sympathetic Nervous System

4. Hormones
Hormones are classified as:
Proteins
Polypeptides (amino acid derivatives)
Lipids (fatty acid derivatives or steroids)

5. Hormones
Amount of hormone reaching target tissue directly
correlates with concentration of hormone in blood.
 Constant level hormones
• Thyroid hormones
 Variable level hormones
• Epinephrine (adrenaline) release
 Cyclic level hormones
• Reproductive hormones

6. The Endocrine System
 Consists of several glands located in various parts of
the body
 Specific Glands
 Hypothalamus
 Pituitary
 Thyroid
 Parathyroid
 Adrenal
 Kidneys
 Pancreatic Islets
 Ovaries
 Testes

7. Hypothalamus
 Produces several releasing and inhibiting factors
that stimulate or inhibit anterior pituitary’s
secretion of hormones.
 Produces hormones that are stored in and released
from posterior pituitary.

8. Hypothalamus
 Also responsible for:
 Regulation of water balance
 Esophageal swallowing
 Body temperature regulation (shivering)
 Food/water intake (appetite)
 Sleep-wake cycle
 Autonomic functions

9. Hypothalamic
 Hypothalamic neural cells synthesize specific
releasing and inhibiting hormones that are
secreted directly into the portal vessels of the
pituitary stalk.
 Hypothalamic-pituitary portal plexus provides
the major blood source for the anterior
pituitary.

10. Hypothalamic releasing hormones
Hypothalamic releasing Effect on pituitary
hormone
Corticotropin releasing hormone Stimulates ACTH secretion
(CRH)
Thyrotropin releasing hormone Stimulates TSH and Prolactin
(TRH) secretion
Growth hormone releasing Stimulates GH secretion
hormone (GHRH)
Somatostatin Inhibits GH (and other hormone)
secretion
Gonadotropin releasing hormone Stimulates LH and FSH
(GnRH) a.k.a LHRH secretion
Prolactin releasing hormone (PRH) Stimulates PRL secretion
Prolactin inhibiting hormone Inhibits PRL secretion
(dopamine)

12. Hypothalamic -Pituitary communication

14. Pituitary Gland
 Small gland located on stalk hanging from base of
brain.
 “The Master Gland”
 Primary function is to control other glands.
 Produces many hormones.
 Secretion is controlled by hypothalamus in base of brain.

15. Pituitary Gland
• Weight 600 mg
• Is located within the bony cavity (sella turcica)
• Anatomically and functionally distinct anterior
and posterior lobes
• Anterior Pituitary-adenohypophysis
• Posterior pituitary-neurohypophysis

16. Histology of the PG
Anterior pituitary cells were originally
classified as
• Acidophils cells
• Basophils cells
• Chromophope cells

17. Histology of PG
Now with immunocytochemical and electron
microscopic techniques,classified cells by their
secretary products
• Somatotrophs cells
• a. GH secreting cells
• Account about 50% of anterior P.G
• Acidophilic stained

18. Histology of PG
• Lactotrophic
• a. Prl secreting cells
• b. acidophilic stained
• c. 10-15% of anterior PG
• Thyrotrophis
• a. TSH secreting cells
• b. basophilic cells
• c. < 10% of anterior PG

19. Histology of PG
• Corticotrophs a.
ACTH secretary cells b.
basophilic cells c. 15-
20% of anterior PG
• Gonadotrophs a.
LH,FSH secretary cells b.
basophilic staining c. 10-
15% of anterior PG

20. Pituitary Development
• The pituitary originate from different source.
• The anterior pituitary from Rathke´s pouch
(which is an embryonic invagination of the pharyngeal
epithelium).
• The posterior pituitary from an outgrow of the
hypothalamus.

21. o Oxytocin,
o Antidiuretic hormone
• Adrenocorticotropic hormone(ACTH)
• Thyroid-stimulating hormone(TSH)
• Growth hormone, Prolactin
• Luteinizing hormone,
• Follicle stimulating hormone
• melanocyte–stimulating hormones

22. Pituitary Gland
 Two areas
Anterior Pituitary
Posterior Pituitary
 Structurally, functionally different

23. Pituitary Gland
 Anterior Pituitary Hormones
 Thyroid-Stimulating Hormone (TSH)
stimulates release of hormones from Thyroid
 thyroxine (T4) and triiodothyronine (T3): stimulate
metabolism of all cells
 calcitonin: lowers the amount of calcium in the blood by
inhibiting breakdown of bone
released when stimulated by TSH
abnormal conditions
 hyperthyroidism: too much TSH release
 hypothyroidism: too little TSH release

24. Pituitary Gland
 Anterior Pituitary
 Growth Hormone (GH)
stimulates growth of all organs and increases blood
glucose concentration
 decreases glucose usage
 increases consumption of fats as an energy source
 Adreno-Corticotrophic Hormone (ACTH)
stimulates the release of adrenal cortex hormones

25. Pituitary Gland
 Anterior Pituitary
 Follicle Stimulating Hormone (FSH)
females - stimulates maturation of ova; release of
estrogen
males - stimulates testes to grow; produce sperm
 Luteinizing Hormone (LH)
females - stimulates ovulation; growth of corpus
luteum
males - stimulates testes to secrete testosterone

26. Pituitary Gland
 Anterior Pituitary
 Prolactin
stimulates breast development during pregnancy;
milk production after delivery
 Melanocyte Stimulating Hormone (MSH)
stimulates synthesis, dispersion of melanin pigment
in skin

27. Pituitary Gland
 Posterior Pituitary
 Stores, releases two hormones produced in
hypothalamus
Antidiuretic hormone (ADH)
Oxytocin

28. Pituitary Gland
 Posterior Pituitary Hormones:
 Antidiuretic hormone (ADH)
Stimulates water retention by kidneys
 reabsorb sodium and water
Abnormal conditions
 Undersecretion: diabetes insipidus (“water diabetes”)
 Oversecretion: Syndrome of Inappropriate Antidiuretic
Hormone (SIADH)
 Oxytocin
Stimulates contraction of uterus at end of pregnancy
(Pitocin®); release of milk from breast

29. Pineal Gland
 Located within the Diencephalon
 Melatonin
 Inhibits ovarian hormones
 May regulate the body’s internal clock

30. Anterior Pituitary
 Isoften referred to as the “MASTER GLAND”
because, it orchestrates the complex regulatory
functions of multiple other endocrine glands.

31. Anterior Pituitary
Insufficiency

32. Etiology
 Reduced pituitary function can result from
inhereited disorders; more commonly,
 it is acquired and reflects the mass effects of
tumors or the consequences of inflamation
or vascular damage.

33. Causes of hypopituitarism
Tumours (tu’) Vascular ds
 Pituitary tumor  Necrosis (Sheehan’s synd)
 Adenoma,craniopharyngioma
 Infarction
 Cerebral tumor
 Severe hypotension
Hypothalamic disorders  Cranial arteritis
 Tumor Trauma
 Functional disturbance-
Eg -Anorexia nervosa
 Isolated GH and GnH secretion Infection
due to impaired secretion of  Meningitis esp TB, syphilis
hypothalamic releasing
hormones
Iatrogenic
Miscellaneous  Surgery
 Sarcoidosis (inflammation of L.N)  Irradiation
 Histocytosis X (abnormal
 Prolonged rx with
increase in the number of immune
cells ) glucocorticoid or thyroid
 Haemochromatosis hormones-isolated ACTH or
TSH suppression

34. Developmental and Genetic Causes of
Hypopituitarism
 Pituitary
Displasia
 Tissue-Specific Factor Mutations
 Developmental Hypotalamic Dysfunction:
 Kallmann Syndrome (Hypogonadotropic hypogonadism)
 Laurence-Moon-Bardet-Biedl Syndrome (involves
many body systems)
 Fröhlich Syndrome (childhood metabolicdisorder)
 Prader-Willi Syndrome.

35. Acquired Hypopituitarism
 Trauma.
 Vascular
 Pituitary or hypothalamic neoplasms
 Inflammatory diseases.
 Infiltrative disorders such as sarcoidosis,
hemochromatosis.

36. ANTERIOR PITUITARY HYPOFUNCTION
(hypopituitarism)
 3 most common causes:
 Non secretory adenoma of ant pituitary
 Sheehan’s syndrome (postpartum pituitary necrosis)
 Empty sella syndrome (pituitary gland become shrinks
or becomes flattened)

37.  Partial hypopituitarism is more frequent than complete
loss of pit functions
 Sx/signs do not manifest until > 75% of ant lobe is
destroyed
 GH secretion is an early feature of pit failure-effects >
dramatic in children but less significant in adults
 LH/ FSH are affected before ACTH
 Hypothyroidism is an uncommon presenting feature of
pit failure

38. Clinical features
Hormone Features of deficiency
GH Children: growth retardation
Adults: ↓muscle bulk
Tendency to hypoglycaemia.
Prolactin Failure of lactation
Gonadotrophins Children: delayed puberty
Female: oligomenorrhoea, infertility,atrophy of breast
& genitalia
Male:Impotence,azoospermia,testicular atrophy
Both sexes: LO libido,LO body hair
ACTH Weight loss, hypotension, hypoglycaemia, decrease skin
pigmentation
TSH Weight gain, cold intolerence,fatique
Vasopressin Thirst, polyuria

39. Posterior Pituitary hypofunction
Causes
 ADH production  cranial diabetes insipidus
(DI)
Causes of cranial DI
 Tumours-craniopharyngioma, secondary tumours
(metastatic CA), pituitary tumours with suprasella
extension.
 Granulomatous disease.
 Meningitis, abscess and encephalitis.
 Vascular disorders.
 Trauma.
 Surgery.
 Idiopathic.

40. Posterior Pituitary hypofunction
Effects
 Polyuria-uncontrolled renal water excretion,
tendency to dehydration
 Polydipsia-excessive thirst, dehydration
stimulate thirst centre resulting in increase
water intake

41. Key features
 Hypotension
 Decreased pulse pressure
 Tachycardia
 Increased Hbg,hct and BUN
 Increased UOP
 Poor skin turgor
 Irritablilty
 Decreased coginition
 Hyperthermia
 Lethargy leading to coma

42. PITUITARY HYPERFUNCTION
(HYPERPITUITARISM)
Hyperpituitarism - excessive production of adenohypophyseal hormones
Causes
 Pituitary adenoma
 Carcinoma (rare)
 Hypothalamic disorder-excess stimulation of the
pituitary (rare)
Order of frequency with which hormone secretion
occurs in pituitary tumour is prolactin (relatively
common) GH  ACTH  gonadotrophin  TSH

43. PITUITARY HYPERFUNCTION
(HYPERPITUITARISM)
Prolactin excess Hyperprolactinaemia
GH excess Acromegaly/ gigantism
ACTH excess Cushing’s disease
TSH excess (rare) Secondary
hyperthyroidism
Gonadotrophin excess menstrual disorders and
infertillity

44. Consequences:
a) Excessive Secretion of prolactin → ↓ secretion of
GnRH → ↓gonadotrophins
In men: impotency, decreased libido
In women: amenorrhea, galactorrhea
b) Excessive Secretion of somatotrophine (growth hormone )
→ acromegaly (in adults)
→ gigantism (in adolescents whose epiphyseal
plates have not yet closed)

45. b)-continuing Pathomechanisms involved :
-The usual GH baseline secretion pattern is lost (as are sleep – related
GH
peaks)
- GH secretion is slightly elevated → ↑somatomedin → stimulation of growth
(in adolescent)
C. In adult s :
- C onnective tissue proliferation
- Bony proliferation → characteristic appearance of acromegaly
- ↑Phosphate reabsorbtion in renal tubules → hyperphosphatemia
- Impairement of carbohydrate tolerance
- ↑ Metabolic rate
- H yperglycemia - it is a result of GH inhibition of peripheral glucose uptake
and increase hepatic glucose production → compensatory hyperinsulinism →
→ insulin resistance → diabetes mellitus

46. D. Excessive Secretion of corticotrophin (ACTH) → central form of
Cushing syndrome (Cushing disease)
Causes: micro- or macroadenomas of adenohypophysis, hypothalamic
disorders
Pathophysiology:
C hronic hypercortisolism is the main disturbance of ↑ ACTH
Symptoms and signs:
• weight gain: - accumulation of adipose tissue in the trunk, facial, and
cervical areas (truncal obesity, moon face, buffalo hump)
- weight gain from Na and water retention
• glucose intolerance → DM type 2
• polyuria: osmotic polyuria due to glycosuria

47. E. Protein Wasting : due to catabolic effects of cortisol on peripheral tissue
(muscle wasting → muscle atrophy and weakness → thin lower
extremities)
→ in bone: - loss of protein matrix → osteoporosis
- ↑blood calcium concentration → renal stones
→ in skin: - loss of collagen → thin, weakened integumentary
tissues → purple striae; rupture of small vesels
- thin, atrophic skin is easily damaged, leading to skin breaks
and ulceration
F. Hyperpigmentation: due to very high levels of ACTH - manifestation
in:
mucous membranes, hair, and skin
• Hypertension: results from permissive effect of cortisol on the actions of
the catecholamines (KA) → ↑ vascular sensitivity to KA →
→ vasoconstriction → hypertension

48. • Suppression of the immune system → ↑ susceptibility to infections
• alteration of mental status - from irritability and depression
up to schizophrenia
• symptoms and signs of ↑ adrenal androgen s level in women:
- ↑ hair growth (especially facial hair)
- acne
- oligoamenorrhea
- changes of the vois
• Hyperglycemia, glycosuria, hypokalemia, metabolic alkalosis
• Excessive Secretion Of Thyreotrophin and Gonadotrophins is rare

50. Measurement of anterior pituitary hormones
 Measured in serum by immunoassay
 Dynamic tests/ functional tests are important tools
in pituitary functions and other endocrine organs.
Basic principle of dynamic tests:
 Hypofunction - stimulation tests
 Hyperfunction-suppression tests
 Magnetic resonance imaging (MRI)

53. Treatment
 Hormone replacement therapy, including
glucocorticoids, thyroid hormone, sex
steroids, growth hormone and vasopressin,
is usually free of complications.
 Glucocorticoid replacement require careful
dose adjustments during stressful events.

54. THANK YOU
QUESTION?????