Urinary system is a type of body function in which harmful (waste) products collected inside cells are removed out from the body. In this system, protein is broken in to urea, uric acid and sulphuric acid. When gases exchange inside the cells, carbon dioxide is collected (produced) and removing it out is very necessary. Urinary system works like a drainage system inside the house in which dirty water is removed out through pipes.
We known that our body needs different types of nutritive substances (elements) like- carbohydrates, protein, fat, etc. for doing various types of body functions. These elements are used by every cells present inside our body and are converted into simpler forms through digestive organs so that they became soluble in water and able to reach to the different parts of the body through blood vessels. When foods break into simpler forms during digestion, few harmful substances (products) also being produced that are removed out from the body through urinary organs.
These harmful substances found inside the body are removed out by a particular type of nisyandko, known as kidneys and the tubes connected with it are known as urinary pipes and urethra. Carbon dioxide is removed out by the lungs and sodium and other biological substances are come out through skin. If these harmful substances did not remove out from the body, various types of diseases are occurred.
There are two bean-shaped kidneys found inside the body and each kidney is about 150g in weight. The kidneys are situated high up at the back of the abdominal cavity one on each side of the vertebral column. if we see a kidney after cutting it as longitudinal section, many small tubes will be seen in it, which are called urinary tubes as well as small blood vessels will be also seen. Both of them have deep relation to each other. The impurities found inside blood are filtered by these kidneys. After filtration, water and other substances are left and removed out from the body in the form of urine.
Comparison between urine and blood-
When we compare the urine with blood, we find that protein and sugar are found in the blood while these are absent in case of urine, however (but) sodium is found in both of them- blood and urine. In urine comparison to blood, 12 times more uric acid, 64 times more urea, 9 times more potassium and 90 times more sulphate, etc. are found.
Figure of urinary system-
The urine (waste products) produced by kidneys is forwarded into bladder through ureter. This bladder is about 30 cm in length. It can hold about 300 to 500 ml urine. With this bladder, a tube remains connected, called urethra. When urinary pressure falls towards this urethra, the bladder muscles are contracted and urine comes out. Urination is controlled by a special part found inside the brain.