Pituitary Gland- Hypophysis- Master Gland

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))

  1. Prolactin

– In female; stimulate growth of mammary gland and milk production

– Inhibit most of the time by Prolactin Inhibiting hormone (PIH) from Hypothalamus

  1. 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

  1. Adrenocorticotropic hormone (ACTH)

-stimulate adrenal cortex to secrete glucocorticoids

-regulated by corticotropic releasing hormone (CRH) and corticotropic inhibiting hormone (CIH) from hypothalamus

  1. 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

  1. Follicle stimulating hormone (FSH)

– stimulate growth of ovarian follicle and secretion of estrogen

– In male, FSH stimulate testis to produce sperm

  1. 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

  1. Oxytocin

  • Stimulus uterus contraction during child birth, milk ejection

Pituitary Gland- Hypophysis- Master Gland

1 Comment

  1. What is the difference between melanin and melanocyte sir?does MSH stimulate production of melanin or melanocyte?

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