Q1-4: These questions are about the structure of the human respiratory system:

1. What is a common name given to the 'trachea'?

• A. the gullet
• B. the windpipe
• C. the throat
• D. the voice box

2. The trachea splits in two, heading to the left and right lungs. These two branch tubes are called..

• A. lungi (left and right lungoles)
• B. bronchi (left and right bronchus)
• C. thorax
• D. diaphragm

3. Air passes into smaller and smaller tubes, eventually reaching tiny sections of air sacs called...

• A. alveoli
• B. raveoli
• C. bronchi
• D. trachi

4. There are estimated to be 6 million of these tiny sections of air sacs in our body. Why are there so many?

• A. to give a large distance for air to travel
• B. to give a very large lung volume for gas exchange to take place
• C. to give a very large surface area for gas exchange to take place
• D. to ensure that if some are damaged, others will still function

5-9: This diagram shows how these air sac sections are responsible for exchanging gases in and out of the blood.

5. What is gas X passing into the blood stream?

• A. oxygen
• B. nitrogen
• C. carbon dioxide
• D. methane

6. What is gas Y passing out of the blood stream?

• A. oxygen
• B. nitrogen
• C. carbon dioxide
• D. methane

7. What is the name given to the tiny blood vessels (tubes) shown in the digram above?

• A. arteries
• B. capillaries
• C. veins
• D. aorta

8. Every cell in our bodies need to use glucose and gas X (shown above) in a chemical reaction to release energy. What is the scientific name for this reaction?

• A. diffusion
• B. perspiration
• C. combustion
• D. respiration

9. There is a high concentration of gas X in the air, and a low concentration in the blood shown in the diagram above. This means gas X pass into the blood in a process called..

• A. diffusion
• B. perspiration
• C. combustion
• D. respiration