Question

1. the amount of chyme (stomach contents) which enters the small intestine is controlled by

a. the release of gastric juice.
b. peristalsis in the esophagus.
c. secretions from the pancreas.
d. constrictions of the pyloric sphincter.

Explanation:

The pyloric sphincter is a ring - like muscle that controls the passage of chyme from the stomach to the small intestine. Gastric juice release (A) is related to digestion in the stomach. Peristalsis in the esophagus (B) is for moving food from the mouth to the stomach. Secretions from the pancreas (C) are for digestion in the small intestine but do not control the amount of chyme entering.

Answer:

D. constrictions of the pyloric sphincter.