Question 1

Which of the following best describes the primary function of the stomach in the mammalian digestive system?

Accepted Answer

Mechanical and chemical breakdown of food into chyme

Question 2

What is the main role of bile salts in the digestive process?

Accepted Answer

They emulsify fats, increasing surface area for enzymatic digestion

Question 3

A patient is prescribed a proton pump inhibitor to treat acid reflux. What is the physiological effect of this medication?

Accepted Answer

It decreases the production of hydrochloric acid in the stomach

Question 4

Which of the following structures is responsible for preventing food from entering the trachea during swallowing?

Accepted Answer

Epiglottis

Question 5

Why is the surface area of the small intestine so large?

Accepted Answer

To maximize nutrient absorption through folds, villi, and microvilli

Question 6

Which enzyme is most active in the acidic environment of the stomach?

Accepted Answer

Pepsin

Question 7

What would likely happen if the mucus layer in the stomach was absent?

Accepted Answer

The stomach lining would be damaged by HCl and pepsin, leading to ulcers

Question 8

Which of the following best explains why laughing while drinking water can cause water to exit through the nostrils?

Accepted Answer

Exhalation during laughter forces water into the nasal passages via the pharynx

Question 9

Which process is responsible for moving food through the esophagus to the stomach?

Accepted Answer

Peristalsis

Question 10

If you mixed gastric juice with crushed food in a test tube, what would you expect to happen?

Accepted Answer

Proteins in the food would be denatured and partially digested into polypeptides

Question 11

Which of the following nutrients is absorbed into the lymphatic system rather than directly into the bloodstream?

Accepted Answer

Chylomicrons (products of fat digestion)

Question 12

What is the main function of the large intestine in the digestive process?

Accepted Answer

Recovery of water and formation of feces

Question 13

Which of the following best describes the positive feedback mechanism in the activation of pepsin in the stomach?

Accepted Answer

Pepsin activates more pepsinogen to pepsin, amplifying protein digestion

Question 14

A person with a blocked bile duct would have difficulty digesting which type of nutrient?

Accepted Answer

Fats

Question 15

Which of the following is a correct sequence of food movement through the human digestive tract?

Accepted Answer

Oral cavity → pharynx → esophagus → stomach → small intestine

Question 16

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

Accepted Answer

Amino acids and glucose are absorbed by active transport, while fructose is absorbed by facilitated diffusion

Question 17

What is the main function of the hepatic portal vein in digestion?

Accepted Answer

It carries nutrient-rich blood from the small intestine to the liver for processing

Question 18

Which of the following would most likely result from a failure of the lower esophageal sphincter to close properly?

Accepted Answer

Acid reflux, causing heartburn

Question 19

Why do bile salts have both hydrophobic and hydrophilic regions?

Accepted Answer

To enable them to emulsify fats by interacting with both lipids and water

Question 20

Which of the following is a likely consequence if the colon reabsorbs too much water?

Accepted Answer

Constipation

The Mammalian Digestive System: Structure and Function

Study Guide - Practice Questions