Question

Pituitary gland is under the control of:
(a) Thyroid gland
(b) Adrenal gland
(b) Adrenal medulla
(b) Hypothalamus

Answer 1

Hint: 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.