Question

Function of ACTH is
A. Stimulate pituitary
B. Stimulate the adrenal cortex to produce hormones
C. Suppress the activity of adrenal cortex
D. Stimulate thyroid

Answer 1

Hint: Trophic hormones are released from the pituitary gland and act on other endocrine glands so that the glands are stimulated to release the hormones.

Complete Answer:
Pituitary gland is the master endocrine gland. It is divided into two parts : Adenohypophysis and Neurohypophysis.
- Hypothalamus is considered to be master of the master endocrine gland. Thus both the parts of the pituitary are directly or indirectly related to Hypothalamus.
1. Adenohypophysis releases hormones under the influence of releasing and inhibiting hormones of hypothalamus. The hormones released by Adenohypophysis are Growth hormone, ACTH, Gonadotrophic hormones, Prolactin, etc.
2. Neurohypophysis does not directly form any hormone. It releases the hormones secreted by hypothalamus.

ACTH:This is Adrenocorticotropic hormone. This is secreted by corticotropic cells of anterior pituitary.
- This hormone is secreted under the influence of CRH (Corticotropic hormones) released by hypothalamus.
- ACTH as the name suggests, acts on Adrenal cortex, Adrenal cortex is the outer part of Adrenal gland, Adrenal gland consists of outer part known as Adrenal cortex and inner part known as Adrenal medulla.
- Adrenal cortex is further divided into three parts : Zona Glomerulosa, Zonal Fasciculata and Zona Reticularis and the hormones secreted are Mineralocorticoids, Glucocorticoids and sex corticoids respectively.
- The hormones are released due to ACTH. Thus the function of ACTH is to stimulate the Adrenal Cortex and Mineralocorticoids regulate sodium metabolism.
- Glucocorticoids regulate carbohydrate metabolism while sex corticoids regulate formation of sexual hormones

Hence the answer is option B.

Note: Adrenal gland consists of two parts. The outer part is Adrenal Cortex and inner is Adrenal Medulla. The outer part is mesodermal in origin while inner is ectodermal in origin.