Question

Give an account on secretions of pituitary gland.

Answer 1

The pituitary gland is present near the hypothalamus of the forebrain, occupying the underside of the brain. It is connected with the hypothalamus by the stalk-like structure called the infundibulum. The pituitary can be divided into lobes called the anterior lobe and the posterior lobe. The anterior lobe is also called adenohypophysis and it receives the inhibiting or stimulating hormones from the hypothalamus via the portal blood vessels and secretes the hormones accordingly. The posterior pituitary also called the neurohypophysis does not secrete its own hormones but receives and stores the hormones of the hypothalamus. The hormones secreted by the adenohypophysis are as follows:

1. Growth Hormone- works on different organs of the body and regulates growth.

2. Thyroid Stimulating Hormone- regulates the release of hormones from the thyroid gland.

3. Adrenocorticotropic Hormone- regulates the release of adrenal gland hormones.

4. Follicle Stimulating Hormone- regulates follicle growth in ovaries of female and spermatogenesis in males.

5. Leutinizing Hormone- regulates the secretion of estrogen by the ovaries in females and the testosterone by the testes in males.

6. Prolactin- stimulates the mammary glands to produce milk during the pregnancy.

7. Melanocyte Stimulating Hormone- Stimulate the melanocytes to produce the pigmentation.

The hormones stored and then released by the posterior pituitary are as follows:

1. Oxytocin- it regulates the contraction of the muscles during the childbirth and stimulates the secretion of milk from the mammary glands.

2. Anti-diuretic hormone or vasopressin- it prevents the loss of water and maintains the blood pressure.