Problem
i. The trachea and the esophagus are located side by side. What mechanisms prevent food from entering the trachea and the lungs when swallowing?
ii. Explain the mechanism that moves food through the gastrointestinal tract.
iii. What is the role of the stomach in digestion? Describe how the structure of the stomach relates to its function.
iv. Strong acids can dissolve or chemically burn living matter. Why is the stomach tissue not damaged by stomach acid? Describe the mechanism by which the stomach lining is protected from the very acidic gastric juice.
v. Pepsinogen is sometimes referred to as a pre-enzyme because it is the inactive form of the enzyme pepsin. Why is it necessary to have a pre enzyme?