Major Difference Between Adrenal Cortex And Adrenal Medulla (With Pictures)

Adrenal glands are endocrine glands located above the kidneys. Each gland has an outer cortex which produces steroid hormones and an inner medulla.  Adrenal cortex produces three main types of steroid hormones, mineralocorticoids, glucocorticoids and adrogens. The adrenal medulla is at the center of each adrenal gland, and is surrounded by the adrenal cortex. It produces the catecholamines adrenaline and noradrenaline, which function to produce a rapid response throughout the body in stress situations. Here are more insights on the two structures differ from one another.

The Differences

Meaning

Adrenal cortex is the outer firm region of the adrenal gland, which secretes steroid hormones to regulate protein, fat metabolism, salt and water balance in the body. In contrast, Adrenal medulla is the central soft surface of the adrenal gland, which secretes epinephrine and norepinephrine in response to acute stress.

Develops from

Adrenal cortex develops from the mesoderm whereas the adrenal medulla develops from the ectoderm.

Color

Adrenal cortex is pale yellowish-pink in color while adrenal medulla is dark reddish brown in color.

Hormones

 Adrenal cortex releases adrogens, mineralocorticoids, and glucocorticoids while the adrenal medulla releases epinephrine and norepinephrine.

Source of hormones

The hormones of the adrenal cortex are released by virtue of ACTH (adrenocorticotrophic hormone) stimulation from the anterior lobe of pituitary gland while the hormones of the adrenal medulla are released because of various nerve signals for stress reaction response.

Composition

Adrenal cortex forms about 75 to 80% of the adrenal gland whereas adrenal medulla forms 20 to 25% of the adrenal gland.

Enclosed

Adrenal cortex is enclosed by a fibrous capsule while adrenal medulla is not enclosed by a fibrous capsule.

Structure

Adrenal cortex comprises three regions which include outer thin zona glomeruiosa, middle thick zona fasciculate and inner thin zona reticularis. In contrast, adrenal medulla is not differentiated into regions. It consists of chromophil cells. The adrenal medulla is simply an extension of the sympathetic nervous system.

Effects of hormone production

Over or under production of hormones from adrenal cortex causes many disorders like Cushing’s disease, Addison’s disease etc. conversely, it is not yet known to cause any disorder from the over or under production of hormones from adrenal medulla.

Importance

Adrenal cortex is essential for life. Its destruction causes death. On the other hand, adrenal medulla is not very much essential. Its destruction does not cause death.

Cooperation with sympathetic nervous system

In the adrenal cortex there is no cooperation between adrenal cortex and sympathetic nervous system whereas in adrenal medulla and sympathetic nervous system function as an integrated system.

Also Read: Difference Between Anti-diuretic Hormone And Aldosterone Hormone

Difference Between Adrenal Cortex And Adrenal Medulla In Tabular Form

Summary

Adrenal cortex is the outer firm region of the adrenal gland, which secretes steroid hormones to regulate protein, fat metabolism, salt and water balance in the body. In contrast, Adrenal medulla is the central soft surface of the adrenal gland, which secretes epinephrine and norepinephrine in response to acute stress.