Question 1

Which of the following best describes the primary function of the hepatic portal system in digestion?

Accepted Answer

It delivers absorbed nutrients directly to the liver for processing before entering systemic circulation.

Question 2

During the cephalic phase of digestion, which neural mechanism is primarily responsible for stimulating saliva production?

Accepted Answer

Parasympathetic innervation via cranial nerves

Question 3

A patient has a mutation in the CFTR chloride channel. Which digestive process is most likely to be affected?

Accepted Answer

Secretion of isotonic NaCl solution by intestinal cells

Question 4

Which layer of the GI tract contains the majority of smooth muscle responsible for peristalsis?

Accepted Answer

Muscularis externa

Question 5

Which hormone is released in response to acid in the intestine and delays gastric emptying?

Accepted Answer

Secretin

Question 6

If the enteric nervous system is damaged, which digestive function would be most directly impaired?

Accepted Answer

Local integration of motility and secretion independent of the CNS

Question 7

Which of the following best explains why vomiting is considered a protective reflex?

Accepted Answer

It expels harmful substances from the GI tract before absorption can occur.

Question 8

Which equation best represents the osmotic movement of water in the small intestine?

Accepted Answer

$$J_w = L_p (\Delta P - \sigma \Delta \pi)$$

Question 9

A patient is unable to digest triglycerides efficiently. Which enzyme is most likely deficient?

Accepted Answer

Pancreatic lipase

Question 10

Which process is responsible for the absorption of glucose in the small intestine?

Accepted Answer

Secondary active transport via SGLT

Question 11

Which of the following is NOT a function of the large intestine?

Accepted Answer

Major absorption of amino acids

Question 12

Which GI hormone is most likely to stimulate pancreatic enzyme secretion after a fatty meal?

Accepted Answer

Cholecystokinin (CCK)

Question 13

Which of the following best describes the role of the myenteric plexus?

Accepted Answer

It regulates the motility of the GI tract by controlling smooth muscle contraction.

Question 14

Which structure is responsible for preventing food from entering the trachea during swallowing?

Accepted Answer

Epiglottis

Question 15

Which of the following best explains the difference between segmentation and peristalsis in the small intestine?

Accepted Answer

Segmentation mixes contents by alternating contractions, while peristalsis propels contents forward.

Question 16

Which of the following is the correct order of layers in the wall of the GI tract from innermost to outermost?

Accepted Answer

Mucosa, submucosa, muscularis externa, serosa

Question 17

Which process is most responsible for the absorption of amino acids in the small intestine?

Accepted Answer

Secondary active transport coupled to Na+

Question 18

A patient presents with decreased secretion of mucus in the stomach. Which cell type is most likely dysfunctional?

Accepted Answer

Mucous cells

Question 19

Which of the following best describes the role of GALT (gut-associated lymphoid tissue) in the digestive system?

Accepted Answer

It samples gut contents and presents antigens to immune cells.

Question 20

Which equation best represents the rate of gastric emptying as a function of stomach volume and pyloric resistance?

Accepted Answer

$$R = \frac{V_{stomach}}{R_{pylorus}}$$

Chapter 21

Study Guide - Practice Questions