Across
- 2. 2 upper chambers called the right and left
- 6. two tubes that travel to the left and right wings
- 9. the vessels connecting atreries to venis
- 10. protein rich liquid
- 11. 2 air filled spongy organs
- 12. thid blood vessel carries blood vessel to the heart
Down
- 1. thin band of muscle involed in breathing
- 3. this blood vessel carries blood away from heart
- 4. 2 lower chambers called the right and left
- 5. air that enters the air sacs is rich in .
- 7. separted into 4 parts
- 8. makes up less then 1% of blood volume