Human skin is made up of three layers: the epidermis, the dermis and the hypodermis, which is also the subcutaneous layer. The subcutaneous layer is primarily made up of fat and connective tissue. The fat insulates the body against both heat and cold, while the blood vessels and nerves woven throughout it help to regulate temperature.
The subcutaneous layer is also an important line of defense, protecting the fragile organs and bones from outside forces, such as pathogens. The subcutaneous layer can be compared to wearing a thermal layer of clothing. This thermal layer acts as an insulator, much like the hypodermis. Also, this layer of fat acts as food storage that the body can use in times of emergency. Finally, the subcutaneous layer gives the body its shape.
The epidermis and dermis also have their own functions. The epidermis helps to keep out bacteria and toxins, holds water, and gives skin its color. The epidermis is made up of collagen, elastin fibers and nerves. This gives skin its elasticity, strength and sensitivity to touch.Learn more about Human Anatomy