Sweat glands, also known as sudoriferous or sudoriparous glands, excrete sweat. These are small tubular structures found within the skin.
There are two main types of sweat glands:
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Eccrine glands: These are the most common type, found across most of the body's skin (except mucous membranes). They produce a watery sweat that helps regulate body temperature. It's estimated there are 2 to 5 million eccrine glands per person. [Source: StatPearls - NCBI Bookshelf] The final sweat excreted is hypotonic. [Source: Physiology of sweat gland function] Eccrine glands also excrete waste products, acting as an excretory organ. [Source: Physiopedia]
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Apocrine glands: These are located in areas with many hair follicles, such as the scalp, armpits, and groin. Their secretion is thicker and contains lipids and proteins, contributing to body odor when acted upon by bacteria. [Source: Mayo Clinic, ASM: Microbial Origins of Body Odor]
While sebaceous glands secrete sebum (an oily substance) through hair follicles, they do not excrete sweat. [Source: Cleveland Clinic - Sebaceous Glands] Sweat glands, however, possess ducts that allow them to excrete substances directly onto the skin's surface. [Source: Cleveland Clinic - Sebaceous Glands] The skin also secretes sebaceous secretions which are sterile and odorless. [Source: ScienceDirect - Sweat Gland] Sweat itself is defined as the excretion of moisture through sweat gland openings. [Source: Merriam-Webster] Exocrine glands, a broader category, are responsible for secreting various substances, including sweat. [Source: Cleveland Clinic - Exocrine Glands]
