Understanding the Cutaneous Glands

There are five types of glands found within the skin; merocrine sweat glands, apocrine sweat glands, sebaceous glands, ceruminous glands and mammary glands. Each of these glands carries out a unique function in the role of the skin.

Sweat Glands
The sweat glands, also known as the sudoriferous glands, are seen in two different forms; merocrine and apocrine. Typically, sweat is composed of 99% water. Each day, around 500 milliliters of insensible perspiration is released from these glands. This perspiration does not create any noticeable wetness on the skin, while diaphoresis, sweating with wetness, does.

Merocrine Sweat Glands
The merocrine sweat glands are the most abundant glands found within the skin. The merocrine sweat glands are responsible for producing the watery perspiration responsible for cooling the body when it becomes overheated. These cells are found in high numbers in the palms, soles and forehead, but are distributed all over the body. Each of these glands is connected to the surface by means of a coiled duct. Located at the deep (bottom) layer of the gland, are myoepithelial cells which behave similarly to smooth muscle, contracting in response to stimulation, squeezing perspiration out of the gland and through the duct.

Apocrine Sweat Glands
The apocrine sweat glands are located in the groin, anal region, axilla, areola, and in men, the beard area. These glands contain ducts, like merocrine glands, except these ducts lead to a hair follicle rather than to the surface of the skin. The sweat produced by apocrine glands is much thicker than sweat produced by merocrine glands due to the high amount of fatty acids found in apocrine gland sweat. Apocrine sweat glands are typically stimulated by stress and sexual arousal and do not typically begin to develop in an individual until puberty. Many researchers believe that the apocrine sweat glands play a role in the release of pheromones.

Sebaceous Glands
Sebaceous glands are small oil-producing glands found in the skin. These glands are typically attached to the hair and create a substance known as sebum. Sebum is responsible for keeping the skin and hair from becoming dry, brittle and cracked. The sebaceous glands are located all over the body, but are not found on the palms or the soles of the feet.

Ceruminous Glands
The ceruminous glands are located in the external ear canal. This gland produces a substance, that when combined with the sebum produced by the sebaceous glands and dead epithelial cells, creates cerumen, or eat wax. Cerumen maintains the felxibility of the eardrum, while waterproofing the ear canal, and protecting the ear from bacteria and foreign matter that may enter the ear.

Mammary Glands
Mammary glands are, contrary to popular belief, present in both men and woman. The mammary glands are often described as modified apocrine sweat glands. These glands are responsible for producing the breast milk meant to sustain offspring.

References
Saladin, Kenneth S.. Anatomy & physiology: the unity of form and function. 5th ed. Dubuque: McGraw-Hill, 2010. Print.

Skin

Cutaneous Glands

What Are Sweat Glands?

Sebaceous Gland (Anatomy)

Skin Glands

What Are Mammary Glands?