Sweat glands or sudoriferous glands are the structures that produce sweat. It is the example of exocrine glands producing and secreting substances onto an epithelium.
There are two types of sudoriferous glands, both of apocrine sweat glands and eccrine sweat glands are inherent only in mammals. They differ in the structure and functioning mechanisms.
The eccrine sweat glands are controlled by the sympathetic nervous system, and they are intended to regulate the body temperature. The secretion of eccrine sudoriferous glands is something like a human's cooling system. It prevents the rising of internal temperature by secreting water to the skin surface. These glands are distributed over the body generally and particularly in palms and soles, then on the head but the least of all on the trunk and the extremities.
Apocrine sweat glands are associated with the hair follicles and produce a fatty sweat. In humans, these glands are mostly restricted to the underarm and genital regions. The glands are passive until the puberty and are stimulated only after the hormonal changes in human's organism.