your body has taken what it needs from the food, waste products are left behind in the blood
and in the large intestine. These waste products need to be removed from the body. The
kidneys work with the lungs, skin, and intestines to keep the correct balance of nutrients,
salts and water in your body.
The Urinary System
Sometimes and confusingly, the urinary system is called the excretory system. But, the
urinary system is only a part of the excretory system. Recall that the excretory system is
made up of the skin, lungs, and large intestine as well as the kidneys. Theurinary system
is the organ system that makes, stores, and gets rid of urine. It includes two kidneys, two
ureters, the bladder, and the urethra. The urinary system is shown inFigure19.13.
Figure 19.13: The kidneys filter the blood that passes through them and the urinary bladder
stores the urine until it is released from the body. ( 8 )
Organs of the Urinary System
As you can see from Figure 1, the kidneys are two bean-shaped organs. Thekidneysfilter
and clean the blood and form urine. They are about the size of your fists and are found near
the middle of the back, just below your rib cage. Theuretersare tube-shaped structures
that bring urine from the kidneys to the urinary bladder. Theurinary bladderis a hollow,