Which of the following would most likely occur if lung cancer restricts the airflow to a group of alveoli?

• A. The surrounding bronchioles would constrict to further limit airflow.
• B. The affected alveoli would receive less oxygen, leading to local hypoxia.
• C. The blood flow to the affected alveoli would increase to compensate for reduced airflow.
• D. The affected alveoli would increase their gas exchange efficiency.

Answer: (B)

Verified step by step guidance

1. Understand the function of alveoli: Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from inhaled air diffuses into the blood, and carbon dioxide from the blood diffuses out to be exhaled.
2. Recognize the impact of restricted airflow: If lung cancer restricts airflow to a group of alveoli, those alveoli will receive less oxygen, which can lead to local hypoxia (a condition where tissues are deprived of adequate oxygen supply).
3. Consider the physiological response to hypoxia: The body typically responds to hypoxia by reducing blood flow to the affected alveoli through a process called hypoxic pulmonary vasoconstriction. This mechanism helps redirect blood to areas of the lung with better oxygenation.
4. Evaluate the incorrect options: Bronchioles constricting further would worsen airflow restriction, which is not a compensatory mechanism. Increasing gas exchange efficiency in affected alveoli is unlikely because their oxygen supply is already compromised.
5. Conclude the correct answer: The affected alveoli would receive less oxygen, leading to local hypoxia, as this aligns with the physiological response to restricted airflow in the lungs.