Adrenal Glands-Hormones and Abnormalities

The adrenals (Adrenal Glands) are two glands located above each kidney. They produce hormones that regulate our body’s response to stress.

A pair of the adrenal is present on top of each kidney. It has two parts;

• Its outer layer is called the adrenal cortex. The adrenal cortex secretes aldosterone and androgenic hormones. The adrenals play a vital role in maintaining homeostasis (the state of balance within the body). When the adrenals fail to function properly, it leads to various health problems.
• Its inner layer is called the adrenal medulla. The medulla produces the hormones adrenaline and noradrenaline.

Adrenal Medulla: Adrenaline And Noradrenaline Hormones

Adrenaline and noradrenaline are secreted in stressful situations.

1. Adrenaline dilates blood vessels in certain parts of the body like skeletal muscles. So it increases the heart output.
2. Noradrenaline constricts blood vessels in certain areas like the gut.

The effect of the two hormones is synergistic in raising blood pressure. Adrenaline and noradrenaline promote the release of glucose from liver glycogen. They reinforce the effects of the sympathetic system.

 Abnormalities: There is rare excess of these hormones. The excess of these hormones can cause abnormally high blood pressure. The adrenal medulla of a rat was removed surgically. Its ability to withstand any stressful situation like cold was reduced.

Cortical Hormones

The adrenal cortex remains active at all times. It becomes more active during aftershocks or stressful situations and infections. It secretes two hormones called Corticosterone Corticosterone is both glucocorticoid and mineralocorticoid. It increases blood glucose levels and regulates mineral ion balance.

Cortisol Or Glucocorticoid:

It increases the blood glucose level. It produces glucose from protein and antagonizes the action of insulin.

Aldosterone or Mineralocorticoid:

It regulates mineral ion balance in the body. Aldosterone prevents the loss of Na ions from the kidney tubules and controls the level of Na ions in the body.

Abnormalities In Cortical Secretions

There are two abnormities in the cortical secretions:

Addison’s Disease:

The destruction of the adrenal cortex occurs in Addison’s disease. It causes general metabolic disturbances. It causes weakness of muscle action and loss of salts. Stress situations like colds lead to collapse and death. Such stress can normally be overcome with help of hormones in the adrenal cortex.

Cushing’s Disease:

The reverse of Addison’s disease is found in Cushing’s disease. In this case, too much cortical hormone is produced. It causes excessive protein breakdown. It results in muscular and bone weakness. High blood sugar disturbs the metabolism like diabetes.

Androgens (e.g. testosterone)

Androgens cause the development of secondary male characteristics. Very small amounts of androgens are secreted in both males and females by adrenal glands. Sometimes, a tumor developed in the inner part of the adrenal cortex in females. It results in the production of androgens in excess amounts. Thus certain male characteristics are developed in such males. Such cases are very rare.

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