Question

Which of the following exerts control over all the others?
A) Adrenal cortex
B) Hypothalamus
C) Thyroid gland
D) Anterior pituitary

Answer 1

Hint: This is located at the base of the diencephalon of the forebrain and is considered a neuroendocrine structure rather than a true endocrine gland. Its secretion is called neurohormone. These hormones reach the pituitary gland through a portal circulatory system and regulate the functions of the anterior pituitary.

Complete step-by-step answer:
Depending on the actions of pituitary hormones, these hormones are called releasing hormones(which stimulate secretion of pituitary hormones) or inhibiting hormones (which inhibit secretions of pituitary hormones). For example, a hypothalamic hormone called gonadotropin-releasing hormone (GnRH) stimulates the pituitary to synthesise and release gonadotropins. And somatostatin inhibits the release of growth hormone from the pituitary that is secreted from the hypothalamus. And pituitary controls all other glands and the pituitary is controlled by the hypothalamus so the master of the master gland is the hypothalamus.
The adrenal cortex produces mineralocorticoids, glucocorticoids, and small amounts of sex hormones called adrenal androgens. aldosterone is regulated independently and is not controlled by the anterior pituitary. The thyroid gland produces thyroxine. These hormones are responsible for the regulation of basal metabolic rate. It elevates the basal metabolic rate in the body tissues. And calcitonin is responsible for osteoblastic activity. The anterior pituitary secretes seven hormones and the release of these hormones is stimulated by releasing hormones and suppressed by inhibiting hormones from the hypothalamus.
Option B is the correct answer.

Note: Anterior and posterior pituitary hormones are controlled by hypothalamus. Hypothalamus regulates directly the posterior pituitary. These hormones control the formation and release of pituitary hormones.