Zona fasciculata

Zona fasciculata is the middle layer of the adrenal cortex, the outer part of the adrenal gland. It lies between the zona glomerulosa and zona reticularis. The cells of the zona fasciculata are responsible for producing glucocorticoids, such as cortisol, which play a crucial role in the body's response to stress.

Structure

The zona fasciculata is the largest of the three layers of the adrenal cortex, making up nearly 80% of the total adrenal cortex volume. The cells in this layer are larger than those in the zona glomerulosa and are arranged in long columns that are perpendicular to the surface of the gland. These cells contain numerous lipid droplets and a large number of mitochondria, reflecting their high metabolic activity.

Function

The primary function of the zona fasciculata is the production of glucocorticoids, primarily cortisol. Cortisol is a steroid hormone that plays a key role in the body's response to stress. It helps to maintain blood glucose levels, suppress the immune response, and aid in the metabolism of fat, protein, and carbohydrates. The production of cortisol is regulated by the hypothalamus and pituitary gland through the release of corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH).

Clinical significance

Dysfunction of the zona fasciculata can lead to a number of medical conditions. Overproduction of cortisol can lead to Cushing's syndrome, characterized by obesity, high blood pressure, and diabetes. Underproduction of cortisol can result in Addison's disease, which can cause fatigue, low blood pressure, and skin discoloration. Both conditions require medical intervention and management.

See also

• Adrenal gland
• Adrenal cortex
• Zona glomerulosa
• Zona reticularis
• Cortisol
• Cushing's syndrome
• Addison's disease