Definition
The sebaceous glands are glands that secrete a fatty secretion called sebum or tallow according to the holocrine mechanism. They belong to the skin appendages, i.e. they are closely connected to the skin, but function independently.
Types of the sebaceous gland
In humans, the sebaceous gland is found almost everywhere on the body in the dermis. Two types of sebaceous glands can be distinguished: In the free glands, the tubular, unbranched ducts are oriented towards the hair shaft and the openings open next to the hairs together with those of the eccrine sweat glands always in the area of the hairs on the surface of the skin.
- Free sebaceous glands (free in the skin) and
- Hair follicle glands (always in relation to a hair follicle)
Occurrence of the sebaceous gland
One finds the free sebaceous gland only in the area of On the remaining skin-surface, however, the hair-ballow-glands are, however, naturally only in the field-skin, therefore the hairy skin (soles and palms contain therefore no sebaceous glands). Here, however, the glands are irregularly distributed. While there are sebaceous glands on the scalp, in the face, in the genital area and along the sweat channel of the upper body in very close density, other regions of the body are only sparsely covered with them. On average, however, one can say that there are about 40 sebaceous glands per square centimeter of skin.
- Lips
- Eyelids
- Anus and
- Genitals
Function of the sebaceous gland
The task of the sebaceous gland is the production of sebum. This is a substance that is largely composed of various fats (triglycerides, fatty acids, waxes and cholesterol) and also contains proteins. The exact composition of the different substances varies from person to person, which contributes to the individual greasiness of the skin.
The amount of sebum produced by the sebaceous gland depends on various factors. Besides various influences of the person himself, environmental influences also play an important role. On average, a person produces about 1 to 2 grams of sebum per day, whereby this secretion naturally decreases with age, which is why the skin of older people becomes drier and therefore more vulnerable. This is because sebum is mainly used to lubricate and protect the skin from drying out.
- Age
- Gender
- Investment
- Hormones
- Nutrition
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