In addition to moving the body, they produce heat, squeeze blood into isolated tissues, maintain posture, and, when exercised, increase endorphin hormones which results in a feeling of well-being. Muscle tissue also surrounds arteries so that blood pressure can be increased where tissue nutrients are most needed. The skin is the largest organ of the body and the most exposed. It is a supple, elastic tissue that conserves heat and moisture. It is the first organ to respond to pain or touch.
Skin also functions as a cooling system and helps regulate internal body temperature.
Hair follicles can be found almost everywhere in the skin. These are oiled from imbedded sebaceous glands, which keep the skin supple and waterproof. Hair helps control body temperature and is made of keratin protein. The root is the only living part and appears to draw toxic metals our of the blood, encapsulating them in dead hair cells that are pushed out of the skin. While hair also protects the body, a nerve attached to each increases the body's sensitivity to touch.