As part of the body's metabollic processes, nitrogenous waste materials are produced. These materials need to be removed from the body.
The system responsible for the removal of such waste is called the excretory system.
Within the excretory system we have a pair of kidneys.
Urine is produced in the kidneys and then passed to the urinary bladder via the ureters.
Urine excretion is the body's way of removing waste products such as urea and uric acid from the blood.
Why is urea formed, you might ask?
It is the digestion of protiens in our diet which lead to creation of urea.
Protiens are broken down into amino acids, these amino acids then form ammonia.
Ammonia is toxic for our body so it is converted to urea and then excreted.
Within the kidneys there exist a cluster of thin walled blood capillaries.
These clusters are associated with a structure known as bowman's capsule.
The bowman's capsule collects the excess water, salt and urea after filtration.
These filtration units in the kidney are known as nephrons.
The urine formed in each kidney is then passed on to the ureters.
The ureters are long tubes which conect the kidneys and the urinary bladder.
Urine is then stored in the bladder. As more urine is produced, pressure in the bladder builds up leading to the urge to release it through the urethra.