The Excretory System

2. The excretory
system
• The excretory system
eliminates (or excretes)
waste products from our
body. Our body excretes
carbon dioxide, urine
and water. The
excretory system
consists of the urinary
system and the sweat
glands.

4. The urinary system
• The urinary system is the
principle way in which the
body gets rid of waste from
blood.
• Research!
• How much litres of urine our
body produce every day?

5. Steps of the urinary system
• 1. The renal arteries carry blood to the kidneys.
• 2. The kidneys eliminate water and waste products from the blood. This
combination of water and harmful substances forms urine.
• 3. Urine leaves the kidneys and passes down through two tubes called the
ureters to the bladder.
• 4. When the bladder is about half-full, it sends signals to the brain that it
needs to be emptied. This is when you want to go to the toilet!
• 5. The bladder is emptied by another tube called urethra.

6. Sweating
• Our body also eliminates
waste products through the
skin. When we get hot,
sweat glands in our skin are
activated to cool down the
body. These glands excrete
sweat which is a mixture of
water and minerals. Sweat
leaves our body through
pores.
• Research! What is sweat
made from?

7. Challenge!
• 1. How is the respiratory system linked to the circulatory system?
• 2. Why is it important for the body to remove waste material?
• 3. Why is it important to sweat? What else can we do to keep cool?
• 4. What should we do keep our excretory and respiratory systems
healthy?