Question
Question: Pituitary gland is under the control of: (a) Thyroid gland (b) Adrenal gland (b) Adrenal medul...
Pituitary gland is under the control of:
(a) Thyroid gland
(b) Adrenal gland
(b) Adrenal medulla
(b) Hypothalamus
Solution
Pituitary gland is also known as hypophysis and is present exactly below the hypothalamus at the base of the brain. Close association of hypothalamus and pituitary gland gives us a clue about regulation of pituitary hormones by hypothalamus.
Complete answer:
Pituitary gland weighs about 0.5 g in humans and is present below the hypothalamus in the forebrain. It plays a major role in controlling growth, blood pressure, regulation of function of sex hormones and metabolism of the body. Via pituitary gland, hypothalamus connects the nervous system to the endocrine system. Hypothalamus secretes releasing hormones which stimulate or inhibit the secretion of pituitary hormones. A summary for these hormones is as follows-
| Hypothalamic hormone | Response by Pituitary | Target organ |
|---|---|---|
| Thyrotropin releasing hormone | Secrets thyroid stimulating hormone | Thyroid |
| Adrenocorticotropin releasing hormone | Secretes adrenocorticotropic hormone | Adrenal cortex |
| Luteinising hormone releasing hormone | Secretes luteinising hormone | Testis/Ovary |
| FSH-releasing hormone | Secretes FSH | Ovaries/Testis |
| Growth hormone releasing/inhibiting hormone or Somatotropin | Inhibits/Promotes growth | All over body |
| Melanocyte stimulating hormone-releasing hormone | Secretes melanocyte releasing hormone |
So, we can see that most of the hormones of pituitary are under the control of Hypothalamus.
Structurally, pituitary gland is divided into three parts i.e. anterior lobe, intermediate lobe and posterior lobe. Anterior lobe is called adenohypophysis and posterior lobe is also called neurohypophysis. The neurohypophysis is connected to the hypothalamus by a small tube called a pituitary stalk.
So, the correct answer is ‘Hypothalamus.'
Note: Thyroid gland is situated in the throat region between the trachea and larynx and secretes a hormone called thyroxine. Adrenal gland is found on the upper region of the kidney and is involved in secretion of many steroid hormones.