Life of every organism depends on certain basic processes. Excretion is one among them. Different organisms follow different modes of excretion. In complex organisms such as humans there is a specialized system for excretion called excretory system. Let’s think and learn more about the excretory system and modes of excretion in animals.
As result of cellular respiration, there are lots of gaseous and other forms of waste products produced within a body. These waste products need to be removed because they are toxic to the body. Excretion is the process of elimination of wastes produced within a body. Various systems in our body help in excretion such as kidney, lungs, skin, eyes, etc.
Human Excretory System
We know that blood transports food, air and water to different parts of our body. It also carries waste products. The human body consists of a specialized system which purifies the blood. This system is known as excretory system. An excretory system comprised of,
- A pair of kidneys
- A pair of ureters
- Urinary bladder
Blood contains both useful and harmful substances. Hence, we have kidneys which separate useful substances by re-absorption and toxic substances by forming urine. Capillaries (a type of blood vessel) of kidneys filter the blood and wastes materials are converted into urine. Urine thus formed will be passed to urinary bladder via ureter. Through the urinary opening at urethra, we excrete urine.
Other than urinary system, skin, lungs and even eyes help us to excrete waste products in different forms. Sweating is a type of excretion where water, urea, and other salts are excreted through skin. Lungs help us to exhale gaseous wastes such as carbon dioxide, nitrogen, etc. Tears produced by our eyes are also a means of excretion.