collecting and removing wastes in the body The Excretory System collecting and removing wastes in the body

The Lungs Air moves through small bronchi tubes into the alveoli of the lungs. Once there oxygen is allowed to pass into the blood, while carbon dioxide is sent out of the blood. Exhaling removes carbon dioxide and some water from the body.

The Kidneys The kidneys eliminate urea (broken down proteins), excess water and other waste materials through the production of urine. The kidneys filter the blood by eliminating wastes within it.

Ureters Narrow tubes that carry urine to the urinary bladder.

Urinary Bladder Urine is stored in a saclike structure called the urinary bladder.

The Urethra Once the bladder is full, urinating causes the urine to flow through a small tube known as the urethra.

The Liver The liver breaks down some foods before they are excreted. The liver also recycles parts of old blood cells into useful substances such as bile, which breaks down fat.

The Skin Sweat glands in the skin remove water and some chemical wastes during perspiration.