Eccrine sweat gland (magnified skin block)

Glandula sudorifera eccrina

Integumentary (skin)SkinLeg

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What it is

A single long tube whose lower end is a tight secretory coil in the deep dermis; its duct climbs through the dermis and corkscrews through the epidermis to open at a sweat pore.

Function

Secretes watery sweat whose evaporation cools the body; up to 2–4 litres an hour in extreme heat.

Size

Coil ~0.4 mm across; 2–4 million glands, densest on palms and soles (~600 per cm²)

Clinical note

Cystic fibrosis raises the salt content of sweat (faulty CFTR chloride channels in the duct), which is the basis of the sweat test.