Wastes in the blood come from tissue breakdown, and from food. After the body takes and uses what it needs, it sends the wastes to the kidneys. The kidneys are bean-shaped organs, about the size of a fist. Having atleast one kidney is mandatory for living, unless treated immidietally. Because of the enormous amounts of blood passing through the kidney, kidneys sxtract 180 liters of fluid daily. If we extracted all of the fluid as urine, we would lose nutrients and dehydrate, Kidneys are responsible for filtering the filtrate and returning most of the solutes and water to the blood.
The Urinary Bladder
After the kidneys filter the fluid, the remaining wastes go to your bladder. The organ stores the urine, and keeps storing it until you can feel it. When you can feel it, it means that the bladder has become full, and you must urinate to release the wastes from your body.
Your skin has a very important part in the excretory system. It holds moisture into every part of your body. In the excretory system, the skins job is to regulate one's body temperature. The salt in the skin helps in evaporation of the water off of the body, to cool off one who is hot. Sweat is excreted through sweat glands. Sweating helps the body maintain a cool, consistent temperature, which also helps one maintain homeostasis.
When we eat fatty foods, the liver orders the gall bladder to release bile into the intestines. The bile then puts the waste products into the intestines. Then the intestines absorb the fats into the blood stream. The liver is then given the blood, and removes all waste products from it as it passes through. The liver removes the iron, which involves red blood cell production. Amino acids are then broken down and passed into the kidney. The kidney uses these to carryout their function in the excretory system. The liver then stores the vitamins, and repeats its cycle.
The lungs play a mandatory role in the excretory system. Your lungs remove the carbon dioxide built up in your blood using specialized cells known as alveoli. Your lungs process the molecules into gas and when you breathe, the gas is ejected from your body. If the lungs did not remove the carbon dioxide from your blood, it would eventually build up, causing a number of different dilemmas in your body.