Just like the other systems, the excretory system is one of them. It is a passive biological system that is very important for organisms as it cleans us. The excretory system removes all unnecessary materials, like water, nitrogen, salts, heat, etc., from our bodies. Removing the waste materials helps maintain the chemical reactions and homeostasis occurring inside the bodies of all organisms. It prevents internal damage and infections inside the body as it causes poisoning. The excretory products are amino acids, urea, uric acid, carbon dioxide, water, and ammonia.
The main excretory organs are:
- A pair of kidneys – there are different harmful molecules found in the blood that are very harmful to our health. Kidneys filter waste blood and clean it.
- A pair of ureters – filters blood and creates urine as a waste product.
- Urinary bladder – it relaxes and expands to store urine inside an organism's body.
- Urethra – removes urine from the body by allowing it to pass.
- The liver – excretes a waste product known as 'bile.'
- Skin – excretes sweat through the surface of the skin.
- Large intestine – removes all the undigested materials from the body that are not needed.
Facts about the human excretory system:
- It helps to remove nitrogenous wastes from the body.
- Kidneys filter and purify the blood, providing our body with cleaner blood.
- Plants can excrete too.
- Excretion is a vital process in organisms.
- Our body contains 70% of water (which is more than blood)
Excretory systems help the body to stay clean from undigested matter by removing them.