Your skin is made up of four layers, making it the largest organ of your body. The outermost layer is known as the epidermis. According to Medical Terminology and Cancer, your epidermis is capable of replenishing dead skin cells. The sloughing off of dead cells protects your skin from drying out. Your epidermis also contains cells that work in conjunction with your body's immune system. The cells act as a barrier to keep foreign invaders away. Your epidermis is also responsible for the creation of your nails. Keratin proteins help to stiffen epidermal tissues, which in turn form your nails.
The dermis is the inner layer of your skin. Within the dermis are glands, hair follicles, connective tissues and blood vessels. The connective tissues of the dermis create collagen fibers. These fibers help maintain your skin's elasticity. Glands within the dermis help to keep your hair and skin soft with the secretion of oils.
Within your brain is the hypothalumus. When you get overheated, the hypothalumus sends signals to your sweat glands. Your sweat glands release sweat to help cool your body. If your body temperature drops, your sweat glands stop the production of sweat to help regulate your body temperature.
The hair on your body has many surprising roles. Hair helps to keep your body temperature level. Your eye lashes, nose and ear hair prevent the entry of harmful debris. Your hair can also act as a barrier to the sun's rays. Your eyebrows prevent sweat from getting into your eyes. The amount of hair on your body can also aid in attracting the opposite sex.
Your skin contains receptors. Without these receptors, you would not be capable of feeling pain, pressure or variations in temperature. Your skin also aids in the absorption of vitamin D, which is essential in the prevention of rickets, a disease characterized by softening of the bones.