CHAPTER 14 – DIGESTION

Question 1

What is the order of structures food passes through in the digestive tract?

Answer 1

Mouth → pharynx → esophagus → stomach → small intestine → large intestine → rectum → anus
Explanation: These organs form the GI tract, which breaks food down and absorbs nutrients.

Question 2

What is peristalsis?

Answer 2

Wave-like muscular contractions that move food forward through the digestive tract.
Explanation: It occurs in the esophagus, stomach, small intestine, and large intestine.

Question 3

Where does carbohydrate digestion begin?

Answer 3

In the mouth, by salivary amylase.
Explanation: This enzyme starts breaking starch into sugars.

Question 4

Where does protein digestion begin?

Answer 4

In the stomach, using pepsin and acid.
Explanation: Acid denatures proteins; pepsin cuts them into peptides.

Question 5

Where does lipid (fat) digestion begin?

Answer 5

Small intestine, with bile + pancreatic lipase.
Explanation: Lipids require emulsification before breakdown.

Question 6

What are 3 functions of the stomach?

Answer 6

1. Stores food
   
   2. Begins protein digestion
   3. Mixes food with acid → becomes chyme
      Explanation: The stomach prepares food for the small intestine.

Question 7

Does the esophagus aid in digestion?

Answer 7

No.
Explanation: It only uses peristalsis to move food to the stomach.

Question 8

Where does most digestion and absorption occur?

Answer 8

Small intestine.
Explanation: Villi and microvilli massively increase nutrient absorption.

Question 9

What structures increase surface area in the small intestine?

Answer 9

Villi + microvilli (“brush border”).
Explanation: More surface area = more absorption.

Question 10

What are the two main digestive functions of the pancreas?

Answer 10

1. Makes digestive enzymes (protease, amylase, lipase)
   
   2. Makes bicarbonate to neutralize stomach acid
      Explanation: The small intestine cannot function in high acidity.

Question 11

What is a NON-digestive function of the pancreas?

Answer 11

Makes insulin and glucagon to regulate blood sugar.

Question 12

What does the liver do in digestion?

Answer 12

Makes bile to help digest fats.
Explanation: It also detoxifies blood and stores nutrients.

Question 13

What does the gallbladder do?

Answer 13

Stores and releases bile.

Question 14

How does the absorption of lipids differ from proteins?

Answer 14

• Proteins/carbs → blood
• Lipids → lymphatic system first
Explanation: Fats are packaged into chylomicrons too large to enter blood capillaries initially.

Question 15

What is emulsification?

Answer 15

Breaking large fat droplets into smaller ones (by bile).
Explanation: This increases surface area for lipase to digest fats.

Question 16

What happens in the large intestine?

Answer 16

• Water absorption
• Vitamin production by bacteria
• Feces formation
Explanation: The microbiome plays a huge role here.

Question 17

What is the most common cause of stomach/intestinal ulcers?

Answer 17

Helicobacter pylori (H. pylori) bacteria.
Explanation: Antibiotics are used to treat most ulcers now.

Question 18

Where is the largest amount of bacteria in the digestive tract?

Answer 18

Large intestine.
Explanation: These bacteria influence immunity, mood, weight, and inflammation.

Question 19

List a few ways the microbiome affects the body.

Answer 19

• Mental health (serotonin production)
• Immune system function
• Brain development
• Digestion efficiency
• Inflammation levels
• Metabolism and weight
• Allergies and autoimmune risks

Question 20

What can you do to build a healthy gut microbiome?

Answer 20

• Eat fiber
• Eat fermented foods (kimchi, yogurt)
• Avoid unnecessary antibiotics
• Reduce sugar intake
• Exercise
• Sleep well
• Reduce stress
Explanation: The microbiome responds strongly to daily habits.

Question 21

A person has trouble digesting fats and their stool looks oily. Which digestive organ is likely malfunctioning?

Answer 21

The gallbladder or liver (not releasing bile).
Explanation: Without bile, fats cannot be emulsified.

Question 22

A patient’s blood sugar stays dangerously high after meals. Which organ may not be functioning properly?

Answer 22

The pancreas (not making insulin).

Question 23

A person can digest carbs and proteins normally but has trouble absorbing fats. Where is the malfunction?

Answer 23

Lymphatic system or bile production.
Explanation: Lipids must enter lymph first.

Question 24

A person takes an antibiotic and then experiences digestive issues and depression-like symptoms. Why?

Answer 24

Antibiotics disrupted their gut microbiome, affecting digestion and neurotransmitter regulation.

Question 25

A patient complains of stomach burning. Antibiotics fix the issue. What caused it?

Answer 25

H. pylori infection causing ulcers.