Question

question 8
which of the following must be relaxed so that defecation can occur?
o the small intestine muscularis
the pyloric sphincter
the stomach muscularis
the external anal sphincter
question 9
gastrin causes the
closing of the lower esophageal sphincter
gastric secretion
the release of cck and secretin
a and b

Explanation:

• Question 8: Defecation involves the expulsion of feces from the body. The external anal sphincter is a voluntary muscle. Relaxing it allows feces to pass out. The small intestine muscularis is involved in digestion and movement of chyme within the small - intestine. The pyloric sphincter controls the passage of chyme from the stomach to the duodenum. The stomach muscularis is involved in churning food.
• Question 9: Gastrin is a hormone. It causes the closing of the lower esophageal sphincter (to prevent reflux) and stimulates gastric secretion (such as hydrochloric acid and pepsinogen secretion). CCK (cholecystokinin) and secretin are released in response to chyme entering the duodenum, not directly by gastrin.

Answer:

• Question 8: the external anal sphincter
• Question 9: A and B