Question 1

Which of the following best describes the primary function of the alimentary canal in the digestive system?

Accepted Answer

It is a continuous tube through which food passes and is digested and absorbed.

Question 2

Which layer of the alimentary canal is responsible for peristalsis and segmentation?

Accepted Answer

Muscularis externa

Question 3

A patient has a deficiency in parietal cell function. Which of the following consequences is most likely?

Accepted Answer

Impaired absorption of vitamin B12

Question 4

Which of the following best explains the role of bile salts in digestion?

Accepted Answer

They emulsify lipids, increasing surface area for enzyme action.

Question 5

During swallowing, which structure prevents food from entering the nasal cavity?

Accepted Answer

Soft palate

Question 6

Which of the following is a correct sequence of events for carbohydrate digestion and absorption?

Accepted Answer

Salivary amylase breaks down starch in the mouth → pancreatic amylase in the small intestine → monosaccharides absorbed by enterocytes

Question 7

A patient with a blocked common bile duct would have difficulty digesting which macronutrient?

Accepted Answer

Lipids

Question 8

Which of the following equations correctly represents the net filtration pressure (NFP) in the glomerulus?

Accepted Answer

$$NFP = GHP - (GCOP + CHP)$$

Question 9

Which hormone increases water reabsorption in the collecting ducts of the kidney by inserting aquaporins into the membrane?

Accepted Answer

Antidiuretic hormone (ADH)

Question 10

A patient is experiencing metabolic acidosis due to kidney dysfunction. Which process is most likely impaired?

Accepted Answer

Tubular secretion of hydrogen ions

Question 11

Which of the following best describes the function of the brush border in the small intestine?

Accepted Answer

It increases surface area and contains enzymes for final digestion of nutrients.

Question 12

Which of the following is a correct description of the role of the hepatic portal vein?

Accepted Answer

It transports nutrient-rich blood from the digestive tract to the liver for processing.

Question 13

Which of the following best explains why the stomach does not digest itself?

Accepted Answer

Mucous neck cells secrete alkaline mucus that protects the stomach lining from acid.

Question 14

Which of the following is the main driving force for glomerular filtration in the kidneys?

Accepted Answer

Glomerular hydrostatic pressure

Question 15

A patient with a mutation that prevents the production of intrinsic factor will most likely develop which condition?

Accepted Answer

Pernicious anemia due to vitamin B12 deficiency

Question 16

Which of the following best describes the process of peristalsis?

Accepted Answer

Alternating contractions of longitudinal and circular muscle layers to propel contents forward

Question 17

Which of the following is a function of the large intestine?

Accepted Answer

Absorption of water and electrolytes

Question 18

Which of the following best explains the effect of aldosterone on the distal tubule and collecting duct?

Accepted Answer

It increases sodium reabsorption and potassium secretion.

Question 19

Which of the following is the correct order of structures that urine passes through after leaving the nephron?

Accepted Answer

Minor calyx → major calyx → renal pelvis → ureter

Question 20

Which of the following best describes the function of the enteric nervous system in the digestive tract?

Accepted Answer

It coordinates local reflexes for secretion and motility within the GI tract.

Digestive System: Structure, Function, and Histology (Unit 3 Test Review, Chapters 22–24)

Study Guide - Practice Questions