subkutan

Subkutan, commonly referred to as subcutaneous in English, denotes the layer of tissue located beneath the dermis of the skin. It is also called the hypodermis. This layer consists mainly of adipose (fat) tissue and loose connective tissue, plus a network of blood vessels and nerves. It serves as insulation, an energy reserve, and a cushion that helps protect underlying muscles and organs. The subcutaneous tissue helps anchor the skin to deeper structures while allowing some movement.

Anatomically, the thickness and composition of subcutaneous tissue vary by body site, sex, age, and body fat. Areas with higher fat deposits tend to be thicker, while vascular and nerve density also influences how substances are absorbed when introduced into this layer. The subcutaneous layer is less densely innervated than the dermis, which contributes to the relatively painless nature of many subcutaneous procedures.

Clinically, the subcutaneous space is important for drug administration and medical devices. Subcutaneous injections deliver medications into this layer, where absorption into the bloodstream occurs gradually. Common injection sites include the abdomen, thighs, and upper arms, with site rotation recommended to minimize tissue changes. Repeated injections at one site can lead to lipodystrophy, such as lipohypertrophy or atrophy. Subcutaneous tissue is also used for implantable devices and cosmetic procedures, including fillers.

See also: hypodermis, subcutaneous injections, lipodystrophy.