Question

What is the sebaceous gland?

Answer 1

A gland is a group of cells in an animal's body that synthesize various substances for release into the bloodstream called endocrine glands or into cavities inside the body or its outer surface called exocrine glands. A sebaceous gland is a microscopic exocrine gland that opens in the skin.

Complete answer:
The sebaceous gland is a small oil-producing gland present in the skin of mammals. Sebaceous glands are usually attached to hair follicles and release a fatty substance called sebum, into the follicular duct and then to the surface of the skin. The glands are distributed over the entire body with the exception of the palms of the hands and the soles of the feet where glands are absent and they are most abundant on the scalp and face.

The sebaceous gland secretes a mixture of fats which includes triglycerides, wax esters, squalene, and cholesterol, and cellular debris which are discharged as sebum through the sebaceous duct connecting the gland to the hair follicle. Sebum helps to form the slightly greasy surface film of the skin and thus helps in keeping the skin flexible and prevents the skin’s loss of absorption of excessive amounts of water.

Thus, Sebaceous glands are small oil-producing exocrine glands.

Note: Sebaceous glands begin to form from embryonic hair follicles during the fourth month of gestation( month of pregnancy ) and are large and well-developed at birth. They shrink during childhood but enlarge again with the onset of puberty thus the maturation of the glands seems to be dependent on circulating levels of male hormones that in particular testosterone.