Excreatory system
There are three main ways we can get rid of substances from our body and they are by breathing we get rid of carbon dioxide and also little particles of water from our body, peeing is another way our kidneys tell us when to get rid of all the toxins we don't need and last of all sweating is another way. We need to get rid of waste because if we dont get rid of it we will get very sick because it is toxic and can poison us.
Skin
The skin gets rid of waste that we don't need by sweating it out of our body, when the panther sweats the body is also cooling itself down because when the wind blows it makes the water sort of cold which cools the body down. The sweat sits on the top of the fur waiting for the wind or some breeze. When the panther is cold the fur and body starts to shiver this creates energy which warms the body up. The fur on its skin slightly stand ecause this creates a layer of oxygen which holds our body warmth in so that we don't get cold and start to warm up. Also the blood supply gets shut off near the bottom of the panthers fur.
Kidney
The kidneys control what comes out in our urine. The urine flows through the ureta pipe which connects up with the bladder. There is urea in the water in the urine which travels out of the body's system. The kidney sorts out what needs to get out of the body and what needs to stop of opening and closing a gate like funnel, it lets the urine get out though closes so that the red blood cells stay in the body. That is what the Nephron cell does and how it operates. The nephron cell is a specialized cell and is also a system in the kidneys. It is a network of tubes that help filter the blood and when it is excreting the rest as urine it reabsorbs the blood so that it doesn't get out of the body. Urine contains salt, urea and water, This is what leaves the body in the urine.
Lungs
When we breath we breathe in oxygen and then when we breathe out we get rid of carbon dioxide which we don't need because it is toxic and could harm us if we don't get rid of the carbon dioxide. The carbon dioxide that we breathe out is waste because we don't need it in our body. The oxygen then goes to muscles that need energy, the oxygen will also go to muscles that need to be repaired.