Metabolic activities of an organism produce several types of by-products. Some of these by-products are waste materials. These waste materials are often toxic in nature and cannot be used in the body. For example, a large amount of carbon dioxide, urea and water is produced in the body by the metabolism of carbohydrates, proteins and fats.
The carbon dioxide is removed by the lungs, while the urea is removed by the kidneys.The process of removal of toxic metabolic wastes from the body is called excretion. And the organs which take part in the excretion of toxic metabolic wastes are called excretory organs. Thus, the lungs and kidneys are the excretory organs of animals.
It should be noted that excess of water present in the body is also a waste product. This excess water is also removed from the body by excretory organs. The process of removal of excess water from the body is called osmoregulation. The system of organs that take part in excretion and osmoregulation of waste products is called excretory system.
Test Your Understanding and Answer These Questions:
- Define excretion, excretory organs and excretory system.
- What is osmoregulation? How does osmoregulation take place in humans?