Final answer:
The incorrect statement regarding human respiratory physiology is C: Airway resistance during inspiration increases. During inspiration, airways expand, which reduces airway resistance, contrary to the claim in statement C.
Step-by-step explanation:
The student has asked which of the following statements is not correct regarding human respiratory physiology:
- A: During quiet breathing, the difference between Palv and Patm is less than 2 mmHg.
- B: The radius of an individual bronchiole is low, but the overall cross-sectional area of the bronchioles is quite high.
- C: Airway resistance during inspiration increases.
- D: In healthy lungs the overall resistance in the conducting zone is low.
Statement C is not correct. During inspiration, the airways actually expand, thereby reducing airway resistance. This is due to the negative pressure created in the thoracic cavity, which dilates the airways, and the increase in the size of the alveoli, which reduces resistance to airflow. Statement A is correct as the pressure difference during quiet breathing is indeed minimal. Statement B is also correct since an individual bronchiole has a small radius but collectively, the bronchioles have a high cross-sectional area, which reduces resistance to airflow. Lastly, statement D is correct since in healthy lungs, the resistance in the conducting zone is generally low because of the large cumulative cross-sectional area of the airways.