EXCRETION

Excretion is the term used to describe the removal of metabolic waste products from the body. Excretion through the skin plays an important role in thermoregulation, electrolyte balance and hydration.

The skin is an excretory organ, although the lungs and the kidneys are the main organs of excretion. The skin efficiently excretes sebum, sweat and waste products through more than two million pores into the environment. These excretions include electrolytes, predominantly sodium chloride, water and other waste products such as urea (Herlihy & Maebius, 2010; Vuolo, 2009).

There is a very small amount of carbon dioxide exchanged through the skin, and it can also provide a minor excretory route for aromatic substances such as garlic.