Compare and contrast the conducting and respiratory zones. 4. A smoker develops damage to several alveoli that then can no longer function. How does this affect gas exchange? 5. Explain how the enteric nervous system supports the digestive system. What might occur that could result in the autonomic nervous system having a negative impact on digestion? II. Critical Thinking Questions. These short answer questions should be answered thoroughly but the responses can be more concise than the essay questions. Use diagrams and images if they will enhance your answer. 1. What layer of the alimentary canal tissue is capable of helping to protect the body against disease, and through what mechanism?