1. An introduction to the urinary system
The body cells are delicate structures that need a closely regulated environment if they are to function efficiently. The urinary system helps control the composition and volume of fluid surrounding the cells.
The principal organs of the urinary system are the kidneys. They:
- filter waste products from the blood to form urine
- control the loss of water and salts from the blood into the urine, so maintaining the correct balance of these substances in the body fluids.
The main waste product in urine is urea, a nitrogen-containing compound that is the final product of protein metabolism.
The formation of urine is a continuous process.
The blood enters each kidney through the renal artery and leaves via the renal vein.
In the kidney, some of the blood is filtered off and processed to remove the waste products that make up urine. The urine drains from the kidneys, through the ureters, into the bladder where it is stored. The urine is discharged from the bladder through the urethra.
Let's learn about each of these structures in more detail.