Question 1

Which of the following best describes the role of the migrating motility complex (MMC) in the gastrointestinal tract?

Accepted Answer

It is a wave of intense contractions that occurs between meals to clear the stomach.

Question 2

A patient experiences delayed gastric emptying after a meal containing large, undigested particles. Based on gastric motility principles, which of the following best explains this phenomenon?

Accepted Answer

Large particles require up to 9 hours to empty from the stomach due to the need for further breakdown.

Question 3

Which of the following statements about the basic electrical rhythm (BER) in gastrointestinal smooth muscle is correct?

Accepted Answer

BER is a series of spontaneous slow waves of depolarization that may or may not reach threshold.

Question 4

During peristalsis in the esophagus, which muscle actions occur in the proximal and distal segments to propel the bolus?

Accepted Answer

Proximal segment: circular muscle contracts, longitudinal muscle relaxes; Distal segment: circular muscle relaxes, longitudinal muscle contracts.

Question 5

Which hormone increases the force of gastric contractions, thereby promoting gastric motility?

Accepted Answer

Gastrin

Question 6

A patient with a spinal cord injury experiences severe distension in the small intestine. Which reflex is most likely to inhibit intestinal contractions in this scenario?

Accepted Answer

Intestino-intestinal reflex

Question 7

Which of the following best explains why the strength of contraction in the intestines varies?

Accepted Answer

It is determined by the frequency of action potentials generated during depolarization.

Question 8

Which of the following is a correct sequence of events during the swallowing reflex?

Accepted Answer

Bolus enters pharynx → epiglottis covers glottis → upper esophageal sphincter opens → peristalsis propels bolus to stomach

Question 9

Which of the following best describes the effect of parasympathetic stimulation on gastrointestinal motility?

Accepted Answer

It excites GI motility by increasing the amplitude of slow waves.

Question 10

Which reflex is responsible for increasing colonic motility and the frequency of mass movements after a meal?

Accepted Answer

Gastrocolic reflex

Question 11

A patient is experiencing pain, fear, and depression. Which phase of gastric motility regulation is most likely being inhibited?

Accepted Answer

Cephalic-phase

Question 12

Which of the following statements about segmentation in the small intestine is correct?

Accepted Answer

Segmentation involves alternating contractions of the circular muscle layer to mix chyme and bring it into contact with the mucosa.

Question 13

Which of the following best describes the defecation reflex?

Accepted Answer

It is initiated by distension of the rectum, leading to contraction of rectal smooth muscle and relaxation of the internal anal sphincter.

Question 14

Which of the following is a function of haustration in the proximal colon?

Accepted Answer

Mixing contents slowly, similar to segmentation but at a slower rate.

Question 15

Which of the following best explains why vomiting can be triggered by motion sickness?

Accepted Answer

Motion sickness stimulates the vomiting center in the medulla oblongata, initiating the vomiting reflex.

Question 16

Which of the following is true regarding the regulation of gastric motility by hormones?

Accepted Answer

CCK, secretin, and GIP decrease the force of gastric contractions.

Question 17

A patient eats a meal and soon after, the presence of chyme in the stomach increases motility in the ileum. Which reflex is responsible for this response?

Accepted Answer

Gastroileal reflex

Question 18

Which of the following best describes the effect of sympathetic stimulation on GI smooth muscle?

Accepted Answer

It inhibits GI motility by decreasing the amplitude of slow waves.

Question 19

Which of the following is a correct statement about the difference between gastric and intestinal smooth muscle contraction?

Accepted Answer

In the intestines, action potentials are required for force generation, while in the stomach, any depolarization can result in contraction.

Gastrointestinal Motility and Its Regulation: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards