Introduction to Excretory system:
To survive human beings need air, food and water and removes water products from body. Carbon dioxide, urine and sweat are produced as body waste products. These need to be continuously removed from body as they are harmful. The process of removal of these products from body is called excretion.
The excretory system is a passive biological system that removes overload, unnecessary or dangerous materials from an organism, so as to help preserve homeostasis within the organism and prevent damage to the body. It is responsible for the removal of the waste products of metabolism as well as other liquid and gaseous wastes.
The major excretory organs are Skin, Lungs and the Kidneys.
Skin as Excretory System
Skin covers the whole human body and is mainly involved in protecting the human body from water loss, germs, sunlight and injury.
It acts as an excretory organ by removing sweat and excess salts from the body.
Lungs as Excretory System
Although lungs are a main component of breathing system as they help us to take in oxygen and out through trachea, bronchi and bronchial, but their significance in excretory system lies as they helps in removal of water vapours and Carbon Dioxide (from blood).
Kidney as Excretory System
Kidneys are bean shaped structures present at back of abdomen and are a part of urinary system. This system helps us to get rid of urine which is a mixture of water, salts and urea.
Urea (Product of protein degradation) is poisonous to our us and needs to be removed.
The Kidney continuously filters the blood to remove urea, excess water and salts (in form of Urine).
The urine flows through the bladder via tubes called ureters. It accumulates in bladder and is finally released when we urinate.
