Which layer of skin is primarily responsible for storing fat?

The hypodermis, also known as the subcutaneous layer, is the layer of skin that is primarily responsible for storing fat. This layer lies beneath the dermis and is composed of loose connective tissue and fat cells (adipocytes). The main functions of the hypodermis include insulation, energy storage, and cushioning for underlying structures such as muscles and bones. The presence of fat in this layer provides thermal insulation, helping to maintain body temperature, and acts as a shock absorber.

In contrast, the epidermis is the outermost layer of skin and is primarily involved in protection and barrier functions; it does not contain fat storage. The dermis, located beneath the epidermis, contains connective tissue, blood vessels, hair follicles, and glands, but is not primarily for fat storage. The stratum corneum is a specific layer of the epidermis that consists of dead skin cells and plays a critical role in barrier protection rather than in the storage of fat. Therefore, the hypodermis is uniquely suited for fat storage due to its composition and location.