pituitary gland

3. Pituitary gland is a small ductless gland of the endocrine system that
secretes directly into the blood stream.
Another name of pituitary gland is “ HYPOPHYSIS”.
Pituitary gland is called the “MASTER GLAND”.
“MASTER'S - MASTER “ i.e. Hypothalamus.
 Hypothalamus is the small region of the of the brain , that located near
the pituitary gland.

4. STRUCTURE
• It is small and oval in shape.
• Reddish-brown or reddish grey color.
SIZE
•Pituitary gland is tiny organ , similar the size of pea.
•Approximately 0.4-0.9 grams weight.
•Dimension is 10x15x5mm.
•Lies at the base of the brain in “Sella turcica”.
•Connected with the Hypothalamus by the pituitary stalk or hypophyseal stalk.

6. ECTODERMAL IN ORIGIN
Arises from pharyngeal epithelium as an upward growth known as “Rathke's pouch”. These
Rathke's pouch further modified to forms “ANTERIOR PITUITARY”.
NEUROECTODERMAL IN ORIGIN
Arises from base of the Diencephalon as a downward diverticulum known as Infundibulam .
Also the downward divrticulum is further modified into”POSTERIOR PITUITARY”.
The Rathke's pouch and downward diverticulum from hypothalamus meet midway between
•The roof of the buccal cavity.
•Base of the brain.

7. Pituitary gland is divided into three portions but, in human only two portions are
functional , these may:-
•ANTERIOR PITUITARY.
•POSTERIOR PITUITARY.
•INTERMEDIATE LOBE.

8.  It is also known as “Adenohypophysis or Pars anterior”.
 It derived from “Rathke’s pouch”.
 Connected to hypothalamus by “Hypothalamo-Hpophyseal portal system”.
 Glandular.
 Anterior pituitary often referred to as “Master gland”.
Anterior pituitary is divided into three parts:
Pars distalis.
Pars tuberalis.
Pars intermedia.

9. Depending upon the staining property , the adenohypophysis cells are divided inyo two types:-
 CHROMOPHILS CELLS:- Contain large number of granules and Darkly stained. It has two
types:-
• Acidophilic or Alpha cells - 35%.
• Basophilic or Beta cells -15%
 CHROMOPHOBE CELLS:
• Do not possess granules -Stained poorly.
• It Comprises about 50% of total cells.

10.  It is also known as “Neurohypophysis or pars nervosa”.
Outgrowth of hypothalamus.
 Connected to hypothalamus by nerve tract by “Hypothalamo-
Hypophyseal tract”.
Non- glandular.
HISTOLOGY
• Consists of axon terminals of hypothalamic neurons and
pituicytes(neuroglia).

11. INTERMEDIATE LOBE
 The intermediate lobe, is just a thin layer of cells between the anterior and
posterior pituitary.
 It is Very small in humans -More functional in lower animals.

12. Hypothalamo-Hypophyseal Relationship
Hypothalamus secretes several hormones to the
•Anterior pituitary.
•Posterior pituitary.
Transportation of hormones
•To Anterior pituitary by Hypothalamo-Hypophyseal portal system.
•To Posterior pituitary by nerve fibers of Hypothalamo-Hypophyseal tract.
Regulation of Anterior Pituitary Secretion.
•Hypothalamus controls Anterior Pituitary through releasing and
inhibitory hormones called neurohormones.

13. ANTERIOR LOBE
 GHRH/GHIH SOMATOTROPHS GROWTH HARMONE(GH)
 PRH/PIH LACTOTROPHS PROLACTIN(PRL)
 GnRH/GnIH GONADOTROPHS GONADOTROPHINS i.e. FSH AND LH
 TRH/TIH THYROTROPHS THYROTROPINORTSH
 CRH/CIH CORTICOTROPHS CORTICOTROPHINS OR ACTH
INTERMEDIATE ZONE
MSH Stimulates melanin formation in melanocytes
POSTERIOR PITUITARY
• Antidiuretic hormone (ADH)
• Oxytocin
HYPOTHALAMIC
HARMONES or
FACTORS
TARGET CELLS
HARMONES SECRETED
BY ADENOHYPOPHYSIS
STAINED CELLS
Acidophils
Basophils

15. • HYPOPITUITARISM:
• PITUITARYTUMORS:

16. •ACROMEGALY:
• GIGANTISM:

17. • CUSHING DISEASE:
• DIABETES INSPIDUS: