$$\mathrm{pH}_{\text{stomach}} \approx 2 \rightarrow \mathrm{pH}_{\text{small intestine}} \approx 8$$

Question 1

Which of the following statements about the movement of food through the gastrointestinal (GI) tract is correct?

Accepted Answer

Movement is typically one way, from mouth to anus, due to coordinated muscular contractions.

Question 2

A patient presents with difficulty digesting fats and pale-colored stools. Which accessory organ is most likely impaired, and why?

Accepted Answer

Gallbladder, because it stores and concentrates bile necessary for fat emulsification.

Question 3

Which enzyme is present in saliva and initiates the digestion of carbohydrates in the mouth?

Accepted Answer

Amylase

Question 4

During swallowing, which structure closes off the trachea to prevent food from entering the airway?

Accepted Answer

Epiglottis

Question 5

Which process is responsible for mixing and moving food through the GI tract by rhythmic contractions?

Accepted Answer

Peristalsis

Question 6

A person with pancreatic cancer may have trouble digesting which macronutrients, and why?

Accepted Answer

Fats, proteins, and carbohydrates, because the pancreas secretes multiple digestive enzymes.

Question 7

Which of the following best describes the role of bile in digestion?

Accepted Answer

Bile emulsifies fats, increasing their surface area for enzyme action.

Question 8

What is the primary function of villi in the small intestine?

Accepted Answer

To increase the surface area for nutrient absorption.

Question 9

Which of the following equations best represents the change in pH as chyme moves from the stomach to the small intestine?

Accepted Answer

$$\mathrm{pH}_{	ext{stomach}} \approx 2 ightarrow \mathrm{pH}_{	ext{small intestine}} \approx 8$$

Question 10

A patient is unable to produce sufficient mucus in the stomach. What is the most likely consequence?

Accepted Answer

Development of stomach ulcers due to acid damage.

Question 11

Which of the following surgical procedures for weight loss is most likely to be reversible, and why?

Accepted Answer

Lap-band, because the band can be removed or adjusted.

Question 12

Which of the following is NOT a function of the pancreas in digestion?

Accepted Answer

Secretion of bile to emulsify fats.

Question 13

Which process in the small intestine is responsible for mixing food back and forth to increase absorption?

Accepted Answer

Segmentation

Question 14

Which of the following best explains why only a small amount of chyme passes through the pyloric sphincter at a time?

Accepted Answer

To allow the small intestine time to neutralize and process the acidic chyme.

Question 15

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

Accepted Answer

Tongue forces food into pharynx, epiglottis closes off trachea, bolus moves into esophagus.

Question 16

Which of the following molecules are actively transported across the epithelial cells of the small intestine into the blood?

Accepted Answer

Monosaccharides and amino acids

Question 17

A patient with esophageal cancer may have difficulty with which phase of digestion?

Accepted Answer

Movement of food from mouth to stomach.

Question 18

Which of the following best describes the process by which chylomicrons leave epithelial cells in the small intestine?

Accepted Answer

Exocytosis

Question 19

Which equation best represents the relationship between surface area and absorption efficiency in the small intestine?

Accepted Answer

$$	ext{Absorption Efficiency} \propto 	ext{Surface Area}$$

Question 20

Which of the following is a direct consequence of a hiatal hernia?

Accepted Answer

Stomach acid entering the esophagus, causing heartburn.

Digestive System: From Mouth to Small Intestine

Study Guide - Practice Questions