Sebum glands are holocrine glands in the body and have the task of producing sebum and protecting the skin from drying out. They are located in the upper part of the dermis and can be found all over the body. They are mostly located in the epithelium of a hair system but can also occur in isolation.
Occurrence of sebum glands
Sebum glands are found almost everywhere on the body. Isolated sebum glands (i.e. without a hair system) are found on:
- Acorn (Glan's penis)
- Inner labia (Labium minus)
Parts of the body without sebum glands are:
There are relatively many sebum glands:
- at the so-called T-zone on the face
- on the scalp
- in the genital area
- on the nipple (see also: Sebum glands of the nipple)
The function of sebum glands
The sebum is produced to keep the horny layer of the skin and around the hair supple and also offers protection against pathogens and chemicals.
Types of sebum glands
There are different names for the different types of glands. This is partly due to their different anatomy and location. For example, sebum glands on the eyelid are transformed into so-called
- Zeis glands and
- Meibomian glands
divided. The sebum glands in the lining of the mouth are called Fordyce's glands.
Histology of the sebaceous glands
Sebum glands have multilayered, piston-shaped glands. It's not an interior (Lumens) visible under the microscope. The wall of the gland is made up of cubic and flattened cells. In the middle of the gland, i.e. in the lumen, you can see fine sebum with a light microscope.
If the gland is associated with a hair, the gland does not have its own exit, but releases its sebum to the hair, which carries it away.
Formation of sebum
Sebum is made up of Fatty acids, wax esters and triglycerides. The sebum is produced by cells that you Sebocytes is called. These cells go after sebum production at the Giving up the sebum (holocrine gland). So are sebum glands even part of the sebum.
Everyone produces different amounts of sebum. It depends on various factors:
- genetic predisposition
- Hormone production
- Environmental influences
The amount of sebum produced is on average approx. 1-2 g sebum per day.
Pathology of the sebaceous glands
If the amount of sebum produced is well above the average, one speaks of Seborrhea, which in the long run can lead to a build-up of secretion. If bacteria then penetrate, so-called blackheads can occur. Acne is also caused by this mechanism.
The opposite of Seborrhea is the Sebobaste. Too little sebum is produced, so the skin is no longer protected from drying out. In rare cases, sebum glands can also degenerate. A sebum carcinoma develops.
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