What is a primary function of the subcutaneous layer?

The primary function of the subcutaneous layer, also known as the hypodermis, is energy storage. This layer is composed mainly of fat cells, which serve as a reservoir of energy. The adipose tissue found in the subcutaneous layer not only provides energy reserves, but also plays a critical role in insulating the body and providing cushioning to protect underlying tissues and organs.

In addition to energy storage, the subcutaneous layer contributes to overall body temperature regulation and acts as a barrier, but these functions are secondary compared to its primary role of energy storage. While the structural support and insulation offered by this layer are important, they arise primarily from its composition of fat cells, highlighting why energy storage is considered the foremost function.