The skin releases toxins from the blood via the sweat glands and pores; these highly vascular, coiled, tubular glands remove waste products from the blood and discharge them from the body in the form of sweat. Sweat is a transparent acidic fluid that contains sodium chloride, water and some urea.
The eccrine glands are the major sweat glands of the human body; they occur over most of the body and directly open onto the surface of the skin. The apocrine glands are found in select areas of the body, where there is an abundance of hair follicles, such as the axillae, or armpits, and some areas of the external genitalia. Apart from excretion, the skin also plays an important role in regulating the temperature of the human body.
When the body gets too hot, the eccrine glands secrete sweat onto the surface of the skin. When the sweat evaporates, it releases heat energy from the skin causing a cooling effect. The skin is also responsible for protecting the body against harmful pollutants, radiation and toxins. It contains millions of nerve endings that relay stimuli allowing the detection of sensations like pressure, pain, cold and heat. The skin is the largest human organ and, despite the fact it plays a small role in excretion, it is vital to human survival.