The Excretory System

1
The Excretory System

• collecting and removing wastes in the body

2
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.

3
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.
  

4
Ureters

• Narrow tubes that carry urine to the urinary
  bladder.

5
Urinary Bladder

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

6
The Urethra

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

7
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.

8
The Skin

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