Question 1

Which of the following best describes the difference between mechanical and chemical digestion in the human digestive tract?

Accepted Answer

Mechanical digestion uses muscular movements to physically break down food, while chemical digestion uses enzymes and acids to break chemical bonds in food molecules.

Question 2

A patient has a blockage at the hepatopancreatic sphincter. Which of the following is the most likely consequence?

Accepted Answer

Bile will accumulate in the gall bladder, and pancreatic enzymes will not enter the duodenum.

Question 3

Which of the following correctly lists the layers of the digestive tract from innermost to outermost?

Accepted Answer

Mucosa, submucosa, muscularis externa, serosa

Question 4

Which enzyme is present in saliva, and what is its primary function?

Accepted Answer

Amylase; begins carbohydrate digestion

Question 5

A person is unable to produce sufficient bicarbonate ions in their pancreatic juice. What is the most likely effect on digestion?

Accepted Answer

The pH of the small intestine will decrease, impairing enzyme activity and nutrient absorption.

Question 6

Which of the following best describes the role of villi in the small intestine?

Accepted Answer

They increase the surface area for absorption of nutrients.

Question 7

During the absorptive state, which hormone is primarily responsible for regulating nutrient storage, and what is its main effect?

Accepted Answer

Insulin; promotes glucose uptake and storage as glycogen

Question 8

Which of the following statements about the citric acid cycle (Krebs cycle) is correct?

Accepted Answer

It occurs in the mitochondria and produces carbon dioxide as a waste product.

Question 9

Which of the following best explains why LDL and HDL levels are important for heart health?

Accepted Answer

High LDL and low HDL levels are associated with increased risk of atherosclerosis.

Question 10

Which of the following is a correct sequence of events during the three phases of swallowing?

Accepted Answer

Buccal phase (voluntary), pharyngeal phase (involuntary), esophageal phase (involuntary)

Question 11

A patient is unable to absorb fats efficiently due to a lack of bile. Which process is most directly impaired?

Accepted Answer

Emulsification of lipids in the small intestine

Question 12

Which of the following best describes the process of gluconeogenesis?

Accepted Answer

The synthesis of glucose from non-carbohydrate sources such as amino acids

Question 13

Which hormone stimulates the release of pancreatic enzymes and bile into the small intestine in response to fatty acids and amino acids?

Accepted Answer

Cholecystokinin (CCK)

Question 14

Which of the following is a function of the mesentery in the digestive system?

Accepted Answer

It supports and stabilizes the position of the intestines and provides a route for blood vessels and nerves.

Question 15

Which of the following best describes the difference between intraperitoneal and retroperitoneal organs?

Accepted Answer

Intraperitoneal organs are completely surrounded by the visceral peritoneum, while retroperitoneal organs are only partially covered.

Question 16

Which of the following equations correctly represents the net ATP yield from aerobic cellular respiration of one molecule of glucose?

Accepted Answer

$$	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6	ext{O}_2 ightarrow 6	ext{CO}_2 + 6	ext{H}_2	ext{O} + 36	ext{ATP}$$

Question 17

Which of the following best explains why added sugars are now reported on nutrition labels?

Accepted Answer

High intake of added sugars is linked to increased risk of metabolic diseases such as obesity and type 2 diabetes.

Question 18

Which of the following is a correct pairing of a pancreatic enzyme and its substrate?

Accepted Answer

Lipase – triglycerides

Question 19

A patient is experiencing frequent heartburn due to improper closure of the lower esophageal sphincter. Which process is most directly affected?

Accepted Answer

Prevention of gastric acid reflux into the esophagus

Question 20

Which of the following best describes the difference between the short and long reflexes in the regulation of digestion?

Accepted Answer

Short reflexes are mediated by the enteric nervous system within the gut wall, while long reflexes involve the central nervous system.

Digestive System and Metabolism Study Guide – Step-by-Step Guidance

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