What is the Adrenal Gland

ADRENAL GLANDS

The adrenal glands are also known as suprarenal glands, are situated on the top of each kidney. Each adrenal gland consists of 2 regions: the outer region which is also known as adrenal cortex and the inner region which is also known as the adrenal medulla.

The adrenal cortex and the adrenal medulla are the two glands in one, each secreting its own different endocrine hormones. The cortex secretes hormones called corticosteroids (complex chemicals derived from cholesterol), and the medulla secretes hormones called catecholamines (chemicals derived from amino acids).

ADRENAL CORTEX

The adrenal cortex secretes 3 types of steroid hormones known as corticosteroids.

1. Mineralocorticoids: The most important hormone of this category is aldosterone. The secretion of aldosterone by the adrenal cortex increases the reabsorption into the bloodstream of sodium by the kidney tubules.
2. Glucocorticoids: Cortisol is the most important glucocorticoid. Cortisol increases the ability of cells to make new sugars out of fats and proteins and regulates the quantity of fat, sugar and proteins in the blood and in the cells.
3. Sex corticoids OR Androgens, Estrogens & Progestins: These hormones are produced by the ovaries and testes. Excess adrenal androgen secretion in female leads to virilism, in which male characteristics are developed and excess adrenal estrogen and progestin secretion in males, produces feminization.

ADRENAL MEDULLA

The adrenal medulla produces 2 types of catecholamine hormones:

1. Epinephrine (adrenaline): This hormone increases cardiac rate, dilates bronchial tubules and stimulates the production of glucose from glycogen, whenever body needs it.
2. Norepinephrine (noradrenaline): This hormone constricts the blood vessels and raises the blood vessels. Both epinephrine and norepinehrine are known as sympathomimetic agents because they mimic or copy the actions of sympathetic nervous system. During stress, fight, fear and fright (3F’s) they are released.

PINEAL GLAND

This gland is located in the central position of the brain and helps in the secretion of the hormone melatonin.

Melatonin helps in the skin pigmentation of the lower animals. In mammals, it regulates the 24 hour clock and regulates gonad maturation too.

Q.1. Human beings possess how many adrenal glands?

1. 2
2. 3
3. 4
4. 5

Ans. 2

Q.2. Where are adrenal glands located in our body?

1. Inside the kidneys.
2. Near the kidneys.
3. Top of each kidney.
4. Under the kidneys.

Ans. c

Q.3. Adrenal medulla is the:

1. Inner region of kidney
2. Outer region of kidney.
3. Umimportant part of kidney
4. Renal capsule.

Ans. a

Q.4. Adrenal cortex is the:

1. Inner region of kidney
2. Outer region of kidney.
3. Umimportant part of kidney
4. Renal capsule.

Ans. b

Q.5. Aldosterone is a:

1. Mineralocorticoid
2. Glucocorticoid
3. Sex corticoid
4. None

Ans. a

Q.6. Cortisol is a:

1. Mineralocorticoid
2. Glucocorticoid
3. Sex corticoid
4. None

Ans. b

Q.7. Adrenal medulla produces:

1. Epinephrine and Nor-epinephrine
2. Aldosterone
3. Cortisol
4. Testosterone

Ans. a

Q.8 Andrgens are:

1. Male hormones
2. Female hormones.
3. Estrogens.
4. Sterile hormones

Ans. a