Photos & Illustrations

Scientific Illustrations | Mar 5, 2001

Representation of a sebaceous gland

scf24_sebaceous_gland big

 

The saccular glandula sebacea hangs at the hair follicle and flows into the hair funnel. It is always located at the acute angle of the hair which sticks in the skin obliquely.

The secretory product of the sebaceous gland films thinly over the hair and surface of the stratum corneum, which may spread up to the upper layers of the stratum corneum. Thus, water permeability is reduced and the resistance to acid, lye and bacterial contamination is increased.

The sebaceous glands are located approximately 0.5 mm under the skin surface. On human skin they are distributed almost over the entire body with the exception of palms and soles (feet). The amount of glands per cm² skin and their size varies considerably. On the scalp, the most and the largest sebaceous glands are to be found, up to 800 per cm².

The sebaceous gland is surrounded by a basal membrane where cells containing relatively small amounts of lipids adhere. After detachment from the basal membrane, the cells fill up more and more with lipids. Their volume grows more than hundred fold until they finally burst and cause the sebum to be expressed into the hair follicle.