Question 1

Which of the following best describes the primary function of bile produced by the liver?

Accepted Answer

Bile emulsifies fats, increasing their surface area for enzymatic digestion.

Question 2

Which cell type in the gastric gland is responsible for secreting hydrochloric acid (HCl) and intrinsic factor?

Accepted Answer

Parietal cells

Question 3

A patient with gallstones is most likely to experience which of the following complications?

Accepted Answer

Blockage of bile flow leading to impaired fat digestion

Question 4

Which phase of gastric secretion is triggered before food enters the stomach, often by the sight, smell, or thought of food?

Accepted Answer

Cephalic reflex phase

Question 5

What is the main reason water is secreted in digestive juices during chemical digestion?

Accepted Answer

To facilitate hydrolysis reactions that break down macromolecules

Question 6

Which enzyme is responsible for the initial breakdown of carbohydrates in the mouth?

Accepted Answer

Salivary amylase

Question 7

A patient with a deficiency in intrinsic factor would most likely develop which condition?

Accepted Answer

Pernicious anemia due to impaired vitamin B12 absorption

Question 8

Which of the following best explains why lipids require emulsification before enzymatic digestion?

Accepted Answer

Lipids are non-polar and form large globules, reducing enzyme access.

Question 9

Which process is illustrated by the equation below, and what is its significance in digestion?

$$	ext{Dipeptide} + H_2O ightarrow 	ext{Amino acid}_1 + 	ext{Amino acid}_2$$

Accepted Answer

Hydrolysis; it breaks down proteins into absorbable amino acids.

Question 10

Which of the following is NOT a function of the liver?

Accepted Answer

Synthesis of vitamin K

Question 11

A patient with a blocked pancreatic duct would have difficulty digesting which macronutrients?

Accepted Answer

Carbohydrates, proteins, and lipids

Question 12

Which of the following best describes the role of bacterial flora in the large intestine?

Accepted Answer

They ferment indigestible carbohydrates and synthesize vitamins B and K.

Question 13

Which of the following best explains why food is considered 'outside' the body until absorption?

Accepted Answer

Food is not in contact with blood until it crosses the epithelial lining of the GI tract.

Question 14

Which of the following is a correct sequence of events for protein digestion?

Accepted Answer

Pepsinogen activated to pepsin in the stomach, then trypsinogen activated to trypsin in the small intestine

Question 15

Which of the following best describes the defecation reflex?

Accepted Answer

A parasympathetic response to rectal filling with feces

Question 16

Which of the following best explains the effect of low stomach pH on salivary amylase?

Accepted Answer

It inactivates salivary amylase, stopping carbohydrate digestion in the stomach.

Question 17

Which of the following is a direct result of the action of bile salts on dietary fats?

Accepted Answer

Emulsification of fats, increasing surface area for lipase action

Question 18

Which of the following best describes the function of the gallbladder?

Accepted Answer

It stores and concentrates bile until needed for digestion.

Question 19

Which of the following is a correct description of the process of peristalsis?

Accepted Answer

A wave-like involuntary muscle contraction that propels food through the alimentary canal

Question 20

Which of the following best explains why lipids are not delivered immediately to the liver after absorption?

Accepted Answer

Lipids are absorbed into lymphatic vessels (lacteals) before entering the bloodstream.

The Digestive System: Structure, Function, and Chemical Digestion

Study Guide - Practice Questions