1. UNIT 2 The nutrition function Natural Science 2. Secondary Education HOW SOME ANIMALS TAKE OXYGEN FROM THE AIR

2. UNIT 2 RESPIRATION IN AIR THROUGH TRACHEAE THROUGH LUNGS Click on each box to find out more How some animals take oxygen from the air is carried out Natural Science 2. Secondary Education

3. UNIT 2 This type of respiration occurs in almost all insects. Tracheae are very thin tubes that branch out to provide the animal’s tissues with oxygen. They lead out of the body through pores called spiracles. Respiration through tracheae CO 2 O2O2 Spiracle Trachea The insect’s tissues Exoskeleton Respiration through tracheae in an insect. How some animals take oxygen from the air Go back to the Start menu Natural Science 2. Secondary Education

4. UNIT 2 This type of respiration occurs in amphibians, reptiles, birds and mammals. Lungs are made up of millions of tiny tubes or cavities called alveoli, which are full of capillaries. This is where oxygen passes into the blood. Lungs are connected to the external environment by the rest of the respiratory tract (airways). Respiration through lungs Blood with O 2 Blood with CO 2 O2O2 CO 2 Respiration through lungs in a mammal. Lungs Airways How some animals take oxygen from the air Go back to the Start menu Natural Science 2. Secondary Education