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What are the differences between the adrenal cortex and adrenal medulla?

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human endocrine system The principal glands of the female and male human endocrine systems.

The adrenal cortex and adrenal medulla are distinct components of the adrenal gland, differing in their embryological origins, structures, and functions.123

Anatomical and Structural Differences

Adrenal Cortex: Comprises approximately 90 percent of the adrenal gland. It is organized into three concentric zones: the zona glomerulosa, zona fasciculata, and zona reticularis. It develops from coelomic epithelium.24
Adrenal Medulla: Makes up about 10 percent of the gland and is embedded in the center of the cortex. It consists of chromaffin cells derived from the embryonic neural crest, functioning as specialized neural tissue.1

Functional and Regulatory Differences

Hormone Production: The cortex synthesizes steroid hormones (corticoids) from cholesterol, including aldosterone, cortisol, and androgens. The medulla secretes catecholamines, specifically dopamine, norepinephrine, and epinephrine.241
Regulation: The cortex is regulated by ACTH and the renin–angiotensin system, whereas the medulla is stimulated by sympathetic nerve impulses.14
Vitality: Unlike the medulla, the adrenocortical tissue is considered essential for life.4