Which gland is stimulated by the sympathetic nervous system?

• A. Eccrine glands
• B. Apocrine glands
• C. Sebaceous glands
• D. Ceruminous glands

Answer: (A)

Sympathetic activation mainly drives sweating through eccrine sweat glands. When the body needs to cool down or respond to stress, postganglionic sympathetic neurons release acetylcholine onto muscarinic receptors on the secretory cells of eccrine glands, triggering watery sweat production. This cholinergic sympathetic pathway is distinctive because most sympathetic fibers use norepinephrine, but eccrine glands respond to acetylcholine. Apocrine glands do respond to sympathetic input as well, but their secretion is more tied to emotional stimuli and hormones and is thicker, contributing to body odor rather than cooling. Sebaceous glands are primarily influenced by androgens and hormonal signals for sebum production, not immediate sympathetic-driven secretion, and ceruminous glands (in the ear) are modified apocrine glands with different roles.