11. The anthers are a green-yellow in colour and they lack an air sac . 12. Veterinarians are planning an MRI to determine the air sac 's condition. 13. The "'alveoli "'are tiny air sacs in the lungs where gas exchange takes place. 14. This is filled with air sacs and fat that aid in buoyancy and biosonar. 15. These bronchioles give rise to the air sacs in the lungs called the alveoli. 16. They have facial air sacs under their skin which cushion the impact with the water. 17. Blood and fluid leak into the spaces between the lung's tiny air sacs , impairing function. 18. State-of-the art ventilators inflate air sacs in their lungs. 19. They have long air sac that serve as lungs that extends from the gill chamber. 20. Respiratory air sacs often form air pockets within the semi-hollow bones of the bird's skeleton.
