What is the subcutaneous layer mainly composed of?

The subcutaneous layer, also known as the hypodermis, is primarily composed of fat and muscle tissue. This layer serves several important functions; it acts as an insulator, helping to regulate body temperature by retaining heat and providing a cushion that protects underlying tissues and organs from external trauma. Additionally, the fat in this layer serves as an energy reserve, providing critical energy during periods of increased metabolic demand.

Muscle tissue supports movement and helps anchor the skin to underlying structures, enhancing stability and functionality. This layer’s composition allows for flexibility and movement of the skin over the muscles and bones beneath it.

The other options do not accurately describe the primary components of the subcutaneous layer. A layer of dead skin cells pertains more to the outermost layer of the skin, the epidermis. Vascular tissue, while present within the skin, does not make up the majority of the subcutaneous layer. Nervous tissue is involved in sensation and communication pathways but is not a predominant component of the hypodermis.