Underskin (Subcutis)

The subcutis consists of loose connective tissue and fatty tissue. It is connected to the periosteum (skin covering the bones) and muscles, but so that it can move relative to them. The fatty tissue in the subcutis serves as a cushion against mechanical impact or pressure (“shock absorber”), as insulation against the cold and as an energy reserve. Carbohydrates absorbed with the food are stored in the form of fat. In the case of a person of normal weight, the fatty tissue accounts for about 10 % of body weight, providing an energy reserve for 40 days. In the case of infants and small children, the heat insulation provided by the fatty tissue is especially important as they have a large body surface relative to their weight.

The fatty tissue is subdivided like a quilt by sections of connective tissue. This connective tissue attaches the skin to the muscles and ensures high elasticity. It is made of collagen and reticulin fibres.

How much fat a person’s body has depends on his or her nutritional status. In women, fat tends to be deposited on the hips, buttocks, thighs and breast, in men on the belly. Areas of skin such as the eyelids, lips, penis and scrotum have little fat. The formation of fatty tissue depends on sex, genetic factors, body region, hormones, age and nutrition.
The subcutis contains the bigger nerves, blood and lymphatic vessels.