Difference Between Adrenal Cortex and Adrenal Medulla

The main difference between adrenal cortex and adrenal medulla is that the adrenal cortex is the outermost covering of the adrenal gland while the adrenal medulla is the inner or middle part of the adrenal gland.

Adrenal Cortex vs. Adrenal Medulla

The adrenal glands are paired structures that sit on top of the kidneys. Each adrenal gland consists of two parts, namely the outer adrenal cortex and the inner adrenal medulla. If we know our anatomy, then there really is no problem describing these two regions. Basically, there are two endocrine organs that are present in the adrenal gland, in which one surrounds the other. The names of these two particular regions indicate their location. The adrenal cortex is the outermost portion of the adrenal gland while the adrenal medulla of the adrenal gland is the inner or middle layer of it. They both release or secrete different types of hormones. The outer adrenal cortex releases three types of hormones, i.e. mineralocorticoids, glucocorticoids and androgens. The inner adrenal medulla, on the other hand, releases two major hormones that include adrenaline (epinephrine) and noradrenaline (norepinephrine). Hormones from the external adrenal cortex are released by virtue of ACTH and are stimulated by the anterior pituitary gland. Hormones from the inner adrenal medulla, on the other hand, are released due to various nerve signals in reaction (response) to stress.

Comparison chart

What is the adrenal cortex ?

The adrenal cortex is the outermost portion of the adrenal gland. Since it is an outer layer, it surrounds the entire medulla. It contains three types of hormones which are androgens, glucocorticoids and mineralocorticoids. The androgen group contains the male sex hormone, which is called testosterone. Glucocorticoids are the group of hormones that consists of the stress hormone (cortisol). Aldosterone is an example of the mineralocorticoid hormone, which is the primary hormone for blood pressure regulation and water reabsorption. The production and release of these hormones are controlled by the pituitary gland (the master gland) primarily with the help of adrenocorticotrophic hormone (ACTH).

What is the adrenal medulla ?

The adrenal medulla is the inner or middle part of the adrenal gland. It has a group of neurons that show a major role in the autonomic nervous system. It releases two types of hormones, namely adrenaline (epinephrine) and noradrenaline (norepinephrine). The effect of these two hormones on the body includes the diversion of blood from the skin (integument) to internal organs such as the brain and liver. They also cause an increase in overall metabolism, dilation of the bronchi and pupils, decreased clotting time, piloerection (skin or hair stands on end like goosebumps or goosebumps), and increased release of ACTH from the anterior pituitary gland. These effects are more or less similar to the effect of the hormones of the adrenal cortex.

Key differences

1. The outermost portion of the adrenal gland is called the adrenal cortex, while the inner or middle part of the adrenal gland is called the adrenal medulla.
2. The adrenal cortex is the outer rigid part of the adrenal gland, while the adrenal medulla is the central soft part of the adrenal gland.
3. The adrenal cortex builds about 75% of the adrenal gland, on the other hand, the adrenal medulla builds about 25% of the adrenal gland.
4. A fibrous capsule surrounds the adrenal cortex. In contrast, the adrenal medulla is not covered by a fibrous capsule.
5. The adrenal cortex develops from the mesoderm, on the other hand, the adrenal medulla develops from the ectoderm.
6. The adrenal cortex contains three zones or regions; on the other hand, the adrenal medulla does not differentiate into zones or regions. It is composed of chromaffin cells.
7. The adrenal cortex is very necessary for life. Its destruction results in death, while the adrenal medulla is not as necessary for life. Its destruction does not result in death.
8. The ACTH of the anterior lobe of the pituitary gland is responsible for stimulating the adrenal cortex to release its hormones, on the other hand, the nerve impulses that arrive through the sympathetic nerve fibers are responsible for stimulating the adrenal medulla to release your hormones. .
9. The adrenal cortex releases three types of hormones including mineralocorticoids, glucocorticoids and androgens while the adrenal medulla releases two major hormones including adrenaline (epinephrine) and noradrenaline (norepinephrine).
10. The adrenal cortex does not cooperate with the sympathetic nervous system; On the other hand, the sympathetic nervous system works with the adrenal medulla as an integrated system called the sympathetic adrenal system.

Final Thought

All of the above discussion summarizes that the adrenal cortex is the outermost part of the adrenal gland that surrounds the adrenal medulla, which is the central portion of the adrenal gland. The former releases hormones such as androgens, glucocorticoids, and mineralocorticoids, while the latter releases hormones such as epinephrine and norepinephrine.