Excretory System Essay

The excretory system is a passive biological system that removes excess, unnecessary materials from the body fluids of an organism, so as to help maintain internal chemical homeostasis and prevent damage to the body. The dual function of excretory systems is the elimination of the waste products of metabolism and to drain the body of used up and broken down components in a liquid and gaseous state. In humans and other amniotes most of these substances leave the body as urine and to some degree exhalation, mammals also expel them through sweating.

Only the organs specifically used for the excretion are considered a part of the excretory system. In the narrow sense, the term refer to the urinary system. However, as excretion involves several functions that are only

It is then secreted within the small intestine where it helps to break down ethanol, fats and other acidic wastes including ammonia, into harmless substances.

Large intestine

The large intestine 's main function is to transport food particles through the body and expel the indigestible parts at the other end, but it also collects waste from throughout the body. The typical brown colour of mammal waste is due to billirubin, a breakdown product of normal heme catabolism. The lower part of the large intestine also extracts any remaining usable water and then removes solid waste. At about 10 feet long in humans, it transports the wastes through the tubes to be excreted.

Skin

In mammals. the skin excretes sweat through sweat glands throughout the body. The sweat, helped by salt, evaporates and helps to keep the body cool when it is warm. In amphibians, the lungs are very simple, and they lack the necessary means to the exhale like other tetrapods can. The moist, scale-less skin is therefore essential in helping to rid the blood of carbon dioxide, and also allows for urea to be expelled through diffusion when