What is the role of the subcutaneous layer in the body?

The subcutaneous layer, also known as the hypodermis, plays a significant role in insulating and protecting underlying structures, such as muscles, bones, and vital organs. This layer is primarily composed of loose connective tissue and fat cells, which serve as a cushion to shield these structures from trauma and temperature fluctuations. The fat within this layer helps to insulate the body, maintaining internal body temperature by reducing heat loss through the skin.

The other roles mentioned do not primarily relate to the subcutaneous layer. While structural support is more accurately provided by the skin and underlying tissues, the regulation of water loss and hormone production are functions more associated with other skin layers or systems in the body.