Adrenal Gland

The adrenal glands are endocrine gland which produces a variety of hormones and are found above the pair of kidneys. These glands are also known as suprarenal glands.

The adrenal glands are absolutely vital for well-being and play a vital role in producing adrenaline, steroids aldosterone, and cortisol hormones.

Adrenal Glands

These glands are mainly found attached above to the kidneys. The human body has two adrenal glands, the right gland is pyramidal in shape and the left gland is semilunar and larger in size. The glands are usually about 5×3 cm in size and their combined weight ranges from 7 to 10 grams. These glands are yellowish in color.

 

Parts of Adrenal Glands

 

Parts of Adrenal Glands

There are three distinct layers of the adrenal glands.

  • Adrenal Capsule

The capsule is a protective layer of fat that surrounds each adrenal glands. They are not strictly a part of the adrenal glands, but the primary function of this capsule layer is to enclose and protect each of the adrenals.

  • Adrenal Cortex

The adrenal cortex is the outermost layer of the adrenal gland which is devoted to the production of aldosterone, cortisol, and androgens hormones. There are three layers of cortex called zones which can be examined and easily differentiated under a microscope. The zona glomerulosa, the zona fasciculata, and the zona reticularis are the layer of the zones which has a different function.

The Glucocorticoids released by the adrenal cortex include:

  1. Hydrocortisone: It is commonly known as cortisol or a steroid hormone. It is involved in regulating body functions like the conversion of fats,  proteins, and carbohydrates to energy and also plays a vital role in other metabolic processes.
  2. Corticosterone: This hormone works with hydrocortisone to control the immune response and prevents the cause of inflammatory reactions.
  • Adrenal Medulla

The last and innermost part of the adrenal gland is the medulla.The chromaffin cells of the medulla are the body’s main source of the Epinephrine and Norepinephrine. The  hormones secreted by the adrenal medulla are:

  1. Epinephrine: This hormone rapidly responds to stress by increasing the heart rate and fastening the blood supply to the muscles and brain.
  2. Norepinephrine: This hormone works with epinephrine in reacting to stress.

To learn more about Adrenal Gland and its hormones, visit Byju’s.


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The attachment of zygote to the wall of uterus is called as _______.