Pituitary Gland- Hypophysis- Master Gland

• Pituitary gland is also known as hypophysis; situated below hypothalamus
• Size: 1 cm long, 1-1.5 cm wide and 0.5 cm thick
• Location: close to optic chiasma in the depression of sphenoid bone
• Pituitary gland has two lobe-anterior and posterior lobe. In between them there is a small region called pars intermedia or intermediate lobe.

Anterior lobe (Adenohypophysis):

• account for 75% of total weight. It consists of functional secretory cell to produce hormones.

Hormones of adenohypophysis

1. Growth hormone (Somatotropin)

• -associate with growth and growth rate of body
• -secretion of GH is controlled by two hormone produced by hypothalamus- Growth hormone releasing hormone (GHRH) and Growth hormone inhibiting hormone(GHIH))

2. Prolactin

• – In female; stimulate growth of mammary gland and milk production
• – Inhibit most of the time by Prolactin Inhibiting hormone (PIH) from Hypothalamus

3. Thyroid stimulating hormone (TSH)

• – stimulate thyroid gland to produce thyroxine
• -secretion of TSH is controlled by thyrotropin releasing hormone (TRH) and thyrotropin inhibitin hormone (TIH) from hypothalamus

4. Adrenocorticotropic hormone (ACTH)

• -stimulate adrenal cortex to secrete glucocorticoids
• -regulated by corticotropic releasing hormone (CRH) and corticotropic inhibiting hormone (CIH) from hypothalamus

5. Luteinizing hormone (LH)

• – stimulate corpus luteum to secrete progesterone and estrogen
• – In male, LH is known as Interstitial cell stimulating hormone (ICSH),it stimulate Interstitial cell of testis to secrete testosterone

6. Follicle stimulating hormone (FSH)

• – stimulate growth of ovarian follicle and secretion of estrogen
• – In male, FSH stimulate testis to produce sperm

7. Melanocytes stimulating hormone (MSH)

• – stimulate melanocyte formation

 Hormones of Neuro-hypophysis

• It doesnot synthesize hormone, rather it stores the hormones produced by hypothalamus

1. Vasopressin (Anti-diuretic hormone)

• -help in osmoregulation
• – increase permeability of PCT, and stimulate reabsorption of water
• – Inhibit by alcohol

2. Oxytocin

• Stimulus uterus contraction during child birth, milk ejection

Pituitary Gland- Hypophysis- Master Gland