All of the glands of the skin are located in the dermis. The place that they are physically supported and gain nutrients. However, they originate in the epidermal layer. Because glands of the skin are externally secreting glands that either through ducts or release their secretions immediately, they are referred to as exocrine. Sudoriferous glands, ceruminous glands and sebaceous glands are three essential kinds of the glands of the skin.
Sudoriferous glands excrete sweat, or perspiration onto the surface of the skin. Water, urea, uric acid and salts are made of perspiration. As a result, on one hand, it is valuable for the excretion of wastes. On the other hand, it is valuable for evaporative cooling. Sweat glands are coiled and tubular shaped, and apocrine and eccrine sweat glands are the two kinds.
- Apocrine sweat glands are quite bigger than the eccrine glands. Apocrine glands are found in the axillary and secrete into hair follicles. They do not have any use till puberty. In addition, their odoriferous secretion are considered as a sexual attractant.
- Eccrine sweat glands are widely spread throughout the body, particularly on the back, palms, soles and forehead.
Only in the external auditory canal, these specialized glands can found. It is a place that they secrete earwax or cerumen. On one hand, cerumen keeps the tympanic membrane from drying out. On the other hand, cerumen is an insect repellent.
Oil or sebaceous glands secrete a lipid mixture named sebum onto the shaft of the hair. Next, the sebum distributes along the shaft of the hair to the surface of the skin. It is a place that it waterproofs and lubricates the skin, and stops the hair from getting brittle.