Before moving on to explore the content, let us discuss about a practical situation that will help us to get a proper understanding about how excretion works. When we do exercises we tend to lose water in the form of sweat. On the same day you do the exercises, you will also notice that you don’t pass urine as usual and it may also take a darker shade. Have you ever wondered as to why this happens? It happens when your body has less water and the kidneys of the excretory system in your body controls the amount of water that is being lost through urine.
What is excretion? Excretion is the process that involves in the removal of wastes and additional water from our body. The excretory products are the useless products or the wastes that are produced during the chemical reactions that take place within the cells. The excretory products of human beings are produced in the excretory organs and are excreted in a particular form. Carbon dioxide and water are produced in the lungs and are excreted as exhaled air. Urea, uric acid, salts and water are produced in the kidneys and skin and are excreted as urine and sweat respectively. However, faeces cannot be considered as an excretory product as it is not produced during the chemical reactions within the cells in the digestive system. These products are harmful to the body and are capable of damaging the cells when large amounts of them get collected. Therefore, the process of excretion removes these toxic products from the body systematically.
Human urinary system
As a result of the chemical reactions that occur within the cells of the human body, nitrogenous by-products are produced and they are excreted from the body as urine through the kidney. The urinary system can be cited as the major nitrogenous excretory system of the body where it helps to eliminate the waste matter and excess water from the body. The urinary system is composed of four major parts namely, the kidneys, ureter or the urinary tract, urinary bladder and urethra.
by Mekhala Egodawele
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