What histological features define the adrenal medulla?

What histological features define the adrenal medulla?

• A. Chromaffin cells arranged in cords; derived from neural crest; secretes catecholamines.
• B. Glomerulosa cells arranged in clusters; secretes mineralocorticoids.
• C. Spongy network of hepatocytes.
• D. Adipose tissue with ducts.

Answer: (A)

Adrenal medulla is defined histologically by chromaffin cells that are organized in cords around capillaries. These neural crest–derived neuroendocrine cells store and rapidly secrete catecholamines (epinephrine and norepinephrine) in response to sympathetic stimulation. The name chromaffin comes from their staining: these cells take up chromium salts and appear brown on chromaffin staining, reflecting their catecholamine content. This makes the medulla distinct from the cortex, which consists of steroid-secreting zones (glomerulosa, fasciculata, reticularis). The other descriptions point to cortical tissue or unrelated tissue, not the medulla.

Adrenal medulla is defined histologically by chromaffin cells that are organized in cords around capillaries. These neural crest–derived neuroendocrine cells store and rapidly secrete catecholamines (epinephrine and norepinephrine) in response to sympathetic stimulation. The name chromaffin comes from their staining: these cells take up chromium salts and appear brown on chromaffin staining, reflecting their catecholamine content. This makes the medulla distinct from the cortex, which consists of steroid-secreting zones (glomerulosa, fasciculata, reticularis). The other descriptions point to cortical tissue or unrelated tissue, not the medulla.