1. Which of the following is the primary site for gas exchange in the respiratory system?

2. The flap-like structure that prevents food from entering the trachea is called:

3. Which structure connects the pharynx to the lungs?

4. What is the function of cilia in the respiratory tract?

5. Which part of the respiratory system contains the vocal cords?

6. Which muscle plays a major role in breathing by contracting and relaxing?

7. During inhalation, the diaphragm:

8. What happens to the pressure inside the lungs when the thoracic cavity expands?

9. Which of the following occurs during exhalation?

10. External respiration refers to:

11. Which of the following is NOT part of the lower respiratory tract?

12. The movement of air into and out of the lungs is called:

13. In which structure does the actual exchange of gases occur?

14. Which of these is a passive process during normal breathing?

15. Oxygen moves from the alveoli into the blood by the process of:

16. What is oxygen debt?

17. Oxygen debt is mainly used to:

18. Lactic acid is produced during:

   19.Which of the following is a direct effect of lactic acid accumulation?

20. Lactic acid buildup occurs when:

21.What is meant by "second wind" in physical activity?

22. Second wind is most commonly experienced in:

23. Vital capacity is defined as:

24. Which of the following factors does NOT affect vital capacity?

25. An athlete is likely to have a higher vital capacity because:

26.Which of the following occurs during aerobic respiration?

27. What are the byproducts of anaerobic respiration in humans?

28.Which type of respiration provides energy for long-duration, low-intensity activities?

29.Anaerobic respiration is more likely to occur during:

30.Which of the following best describes the energy yield of aerobic respiration?

31.Which of the following is a cardiovascular benefit of regular aerobic exercise?

32.Exercise helps regulate body weight by:

33.Regular physical activity helps reduce the risk of:

34. One benefit of resistance or strength training is:

35.Which hormone is commonly released during exercise and improves mood?