hypoderme

Hypoderme, more commonly called the hypodermis or subcutaneous tissue, is the deepest layer of the skin, lying beneath the dermis and blending with underlying fascia and muscles. It serves as a transition zone between the skin and deeper structures and helps anchor the skin to the body’s tissues.

The hypoderme is composed mainly of loose connective tissue and adipose (fat) tissue, arranged in fat lobules separated by connective septa. This fat layer varies in thickness by region, age, sex, and overall body fat. It also contains a network of blood vessels, lymphatic vessels, and nerves that supply the skin. Sweat glands and hair follicles exist in the dermis and its appendages; they are not located within the hypoderme.

Functions of the hypodermis include energy storage in the form of fat, insulation to reduce heat loss, and mechanical cushioning that protects underlying muscles and bones from trauma. It also provides a pathway for blood vessels and nerves to reach the dermis.

Clinical relevance: the hypoderme is the target of subcutaneous injections (hypodermic injections) because it lies just under the dermis. Its appearance and thickness can be altered by obesity, lipodystrophy, and cellulite, and conditions affecting adipose tissue can influence its structure and function.

In summary, the hypoderme is a loosly organized, fat-rich layer that supports, insulates, and nourishes the skin while connecting it to deeper tissues.