Question

List the hormones secreted by the adrenal gland.

Answer 1

Hint: Adrenal glands are also known as suprarenal glands. This is because they are located on the top kidneys. They are small paired structures enclosed within a fibrous capsule. Hormones are chemical substances secreted by glands to regulate specific body functions, such as metabolism, growth and reproduction.

Complete answer:
Each adrenal gland is composed of an outer cortex and an inner medulla. Both of these have different embryonic origin, structure and functions. An adrenal glands produce a variety of hormones that are very important for the normal functioning of the body.

Hormones of the adrenal cortex are synthesized from cholesterol and are called corticosteroids. These are mineralocorticoid, glucocorticoid and gonadocorticoids.
- Mineralocorticoids are responsible for the regulation of mineral metabolism. They regulate the sodium level in the body. E.g. Aldosterone.
- Glucocorticoids are mainly responsible for carbohydrate metabolism in the liver. They include three main hormones: Cortisol, Corticosterone and Cortisone.
- Gonadcorticoids or sex corticoids are sex hormones. Male sex corticoid is called Androgen and female sex corticoid is called Estrogen. Androgen stimulates the development of secondary sexual characters in males like distribution of body hair, deep voice and masculine features. Estrogen stimulates the development of secondary sexual characters in females.

Hormones secreted by the adrenal medulla are called catecholamines. They act as hormones as well as neurotransmitters and manage the body's response to stress. They are important hormones for fight and flight response. These are epinephrine and norepinephrine.
- Epinephrine is also known as adrenaline. It is released during a sudden shock or fear and results in increased heart rate, blood pressure and blood sugar levels.
- Norepinephrine or noradrenaline secretion constrict the blood vessels at the time of stress thereby increasing heart rate, blood pressure and blood sugar.

Note: Disorder of the adrenal cortex may cause a disease in the organism. Deficiency of mineralocorticoids and glucocorticoids cause Addison’s disease. Gynaecomastia is a condition when mammary glands become enlarged in the males due to excessive secretion of estrogen.
Cortisol is an immunosuppressive hormone as it suppresses the synthesis of antibodies by inhibiting the production of lymphocytes in the lymphoid tissues.