1. Maintaining Homeostasis

2. Respiratory System Brings oxygen into the body Needs a moist surface to collect air - Gills- feathery structure exposing a large area - Lungs- organs that exchange carbon dioxide between the air and blood Circulatory system takes the gained oxygen and transports it to the rest of the body

3. Gills

4. Lungs

5. Circulatory System Transport oxygen and nutrients throughout the body with blood Open circulatory system- Blood transported throughout body Closed circulatory system- Blood is contained to just blood vessels

6. Open/Closed Circulatory System

7. Ectotherms Animals who depend on their environment to help maintain their body temperature Most reptiles, fishes, invertebrates and amphibians Lack proper body insulation - Bask in the sun for warmth - Hide in underground tunnels when it is too warm or cold

8. Endotherms Animals whose body temperatures are regulated by heat generated from its body Birds- use feathers to keep insulated Mammals- use body fat and hair for insulation - Use panting and sweating to reduce body heat

9. Endocrine Glands Release hormones into blood to regulate body activities Part of the endocrine system