Part 3: Fill in the blanks 10. The tiny air sacs in the lungs where gas exchange occurs are called __ 11. The process by which oxygen and carbon dioxide move across the alveolar-capillary membrane is called __ 12. Breathing rate is __ 13. The chemoreceptor present in the brain are called __ 14. The pressure difference that drives air into the lungs is called __ 15. Function of __ is increases depth of inspiration by acting directly on the inspiratory center.

10. The tiny air sacs in the lungs where gas exchange occurs are called **alveoli**.<br /><br />11. The process by which oxygen and carbon dioxide move across the alveolar-capillary membrane is called **diffusion**.<br /><br />12. Breathing rate is **the number of breaths taken per minute**.<br /><br />13. The chemoreceptors present in the brain are called **central chemoreceptors**.<br /><br />14. The pressure difference that drives air into the lungs is called **transpulmonary pressure**.<br /><br />15. Function of **pontine respiratory group** is to increase the depth of inspiration by acting directly on the inspiratory center.