The kidneys do three main things
- They remove urea from the blood
- They control the amount of ions (salts) in the blood
- They control the water content of the blood
Urea is produced in the liver where proteins (which can’t be stored) are broken down into fats and carbohydrates, with the waste product as urea it is filtered out of the blood by the kidneys, because urea is poisonous.
Salts are eaten, and while the body needs some salts, a salty meal (for example) however, will have far too much salt, so kidneys will filter out the excess salts.
The kidneys are made up of the medulla and the cortex. The cortex is the lighter exterior, while the medulla is an area made up of feathery like structures closer to the centre which are attached to the…