Sweat gland

A sweat gland is a small tubular structure of the skin that produces sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial surface by way of a duct.

Types of Sweat Glands

There are two main types of sweat glands that differ in their structure, function, secretory product, mechanism of excretion, anatomic distribution, and distribution across species:

1. Eccrine sweat glands: These are distributed almost all over the human body, in varying densities, but their highest density is found on the palms of the hands, soles of the feet, and the forehead. They are active in thermoregulation by providing cooling from the evaporative cooling of sweat.

2. Apocrine sweat glands: These are larger than eccrine sweat glands and are found only in certain locations of the body: the axillae (armpits), areola and nipples of the breast, ear canal, eyelids, wings of the nostril, perianal region, and some parts of the external genitalia. They are responsible for body odor.

Function

The primary function of sweat glands is body temperature regulation. However, they also play a role in the immune system by keeping the skin moist, which helps prevent the skin from becoming dry, cracked, and susceptible to microbial invasion.

Clinical significance

Dysfunction of the sweat glands can be a significant problem. Some people have hyperhidrosis, which is a condition characterized by excessive sweating, often in specific areas of the body. On the other hand, anhidrosis is a condition where the body does not produce enough sweat, which can lead to overheating.

See also

• Thermoregulation
• Exocrine gland
• Hyperhidrosis
• Anhidrosis

External links

• Sweat Gland at Encyclopædia Britannica
• Sweat Gland Disorders at PubMed Health

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  Diagram of human skin structure
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  Illustration of sweat glands
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  Fingerprint showing sweat gland openings
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  Apocrine sweat gland
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  Detailed view of a sweat gland
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  Various types of sweat glands