Sweat glands secrete sweat, also known as perspiration. This fluid is primarily composed of water, but also contains various electrolytes like sodium and potassium ions.
Types of Sweat Glands and Their Secretions
There are different types of sweat glands, each with slightly varying secretions:
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Eccrine glands: These are the most common type and are found throughout the body. Their initial secretion contains water, sodium, and potassium ions. However, the ducts reabsorb a significant portion of these ions, resulting in sweat that's largely water. [Reference: The initial sweat released by eccrine glands is made up of water as well as sodium and potassium ions; however, the epithelial lining of the ducts reabsorbs a majority of these ions, resulting in a larger water composition of sweat.] Eccrine sweat also contains chemicals from the interstitial fluid and the eccrine gland itself. [Reference: The contents of eccrine sweat are mainly water and NaCl. It also contains chemicals from the interstitial fluid and the eccrine gland.]
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Apocrine glands: These glands become active during puberty and are located in areas like the armpits and groin. While they produce copious amounts of watery fluid similar to eccrine sweat, their exact function remains unclear. [Reference: In addition, the apoeccrine gland produces copious salt water secretions similar to eccrine sweat [23]. The function of this secretion is unknown, but unlikely…][Reference: Apoeccrine glands, which contribute notably to axillary secretion by emitting high amounts of watery fluid, show strong cholinergic sensitivity,… ] Apocrine glands present at birth do not become active until puberty. [Reference: Apocrine glands present at birth do not become active until puberty.]
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Sebaceous glands: Although not sweat glands, it's important to distinguish them. These glands secrete sebum, an oily substance, into hair follicles. [Reference: Sebaceous glands are microscopic glands found in your hair follicles that secrete sebum. Sebum is an oily substance that… ]
The composition of sweat can vary depending on factors like hydration, body temperature, and individual differences. Sweat plays a vital role in thermoregulation, helping to cool the body down through evaporation.
