Which type of epithelial glandular secretion is exemplified by eccrine sweat glands?

• A. Holocrine
• B. Apocrine
• C. Merocrine
• D. Endocrine

Answer: (C)

In eccrine sweat glands, secretion occurs by merocrine discharge. This means the secretory cells release sweat through exocytosis, sending vesicles to the cell surface where they fuse with the membrane and release their contents, all without damaging or destroying the secretory cells themselves. The gland stays intact and continues producing, which fits the watery, abundant sweat these glands produce to help cool the body.

This contrasts with holocrine secretion, where entire cells disintegrate to release their contents (as in sebaceous glands), apocrine secretion, where a portion of the cell apical cytoplasm pinches off, and endocrine secretion, where products are released directly into the bloodstream rather than through a duct.