What type of tissue is primarily responsible for insulation and nutrient storage beneath the skin?

Subcutaneous tissue, also known as hypodermis or superficial fascia, is the layer of tissue located beneath the skin that plays a critical role in insulation and nutrient storage. Comprising adipose tissue and connective tissue, it serves as a reservoir for fat, which provides energy storage as well as thermal insulation that helps to regulate body temperature. This layer also aids in cushioning the body against external physical trauma and anchors the skin to underlying structures like muscles and bones.

In contrast, the dermis is the layer of skin that contains connective tissue, blood vessels, and nerve endings but does not primarily serve the function of insulation or nutrient storage. The epidermis is the outermost layer of skin that mainly provides a protective barrier and does not contain significant fat or connective tissue for insulation. Fibrous tissue generally refers to connective tissue that provides structural support and does not specifically pertain to insulation or nutrient storage beneath the skin. Thus, the subcutaneous tissue is accurately identified as the primary tissue responsible for these functions.