Structure
1. In terms of the structures that air passes through as you breathe in, put the following in the correct order: lungs; nasal cavity; bronchi; trachea.
Answer: nasal cavity; trachea; bronchi; lungs
2. What are the two phases of activity in the lungs? Which structures does air pass through after the bronchi? What are the functional units of the lungs?
Answer: insipration; expiration; bronchioles; alveoli.
Function
3. What is the major constituent of air? Which constituent of air is accumulated in the blood at the alveoli? Which constituent of air is removed from the blood at the alveoli? What is the exchange of these constituents called?
Answer: nitrogen; oxygen; carbon dioxide; respiration.
4. What happens at inspiration?
Answer: the diaphragm descends & the rib cage rises; pressure inside thorax falls; lungs expand; air enters lungs.
5. Describe the structure of the alveoli. By what process is oxygen and carbon dioxide exchanged at the alveoli?
Answer: small sacs; single cell layer; close proximity to pulmonary capillaries; diffusion.
