Chapter 4: Human Digestion & Absorption

Question 1

What is the role of the digestive system?

Answer 1

break down and digest food

Question 2

GI tract flow:

Answer 2

mouth -> esophagus -> stomach -> small intestine -> large intestine -> rectum -> anus

Question 3

List the accessory organs:

Answer 3

liver, pancreas, gallbladder

Question 4

Nutrients must pass through the wall of what tube to be absorbed in the body?

Answer 4

Alimentary canal

Question 5

What is a sphincter, where are they located, and what is their function? List the sphincters in
order from mouth to anus.

Answer 5

ring-like muscles that control the flow of contents

lower esophageal, pyloric, sphincter of Oddi, ileocecal valve, anal sphincter

Question 6

Segmentation vs. peristalsis

Answer 6

segmentation = back & forth movement
peristalsis = moves food down

Question 7

What are digestive enzymes and where are they produced?

Answer 7

speed up reactions to cause digestion, produced by mouth, stomach, small intestine, & pancreas

Question 8

Hydrolysis reactions are needed to break down _________.

Answer 8

large molecules

Question 9

Where does digestion begin? What enzyme is present?

Answer 9

the mouth, saliva

Question 10

Describe the process of swallowing. What is the epiglottis?

Answer 10

bolus -> esophagus, prevents food from entering trachea

Question 11

The food enters the _____ next through the ______ located between the _______.

Answer 11

stomach, esophageal sphincter, esophagus & stomahch

Question 12

What is chyme? How does it aid in digestion?

Answer 12

mixes stomach contents w/ secretions

Question 13

What is the role of mucus in the stomach and what cells secrete it?

Answer 13

the stomach secretes mucus to protect the stomach from digestion by HCl & pepsin, secreted by mucus cells

Question 14

Small intestine is the major site of _____.

Answer 14

absorption

Question 15

Describe the surface of the small intestine. How does it move chyme?

Answer 15

increases surface area, mixed chyme with digestive juices & brings nutrients into contact with villi

Question 16

Villi are lined with ________, which___________.

Answer 16

enterocytes, secrete enzymes & absorb nutients

Question 17

Digestion in the small intestine depends on secretions from _______.

Answer 17

brush border

Question 18

Where are the secretions from the liver, gallbladder, and pancreas delivered?

Answer 18

the duodenum (top section of SI)

Question 19

What does the liver produce to help with digestion? How does it help? Where is it stored?

Answer 19

bile, aids in fat digestion, stored in gallbladder

Question 20

What does the pancreas produce? What does the secretion do?

Answer 20

sodium bicarbonate = neutralize chyme
amylase = digest starch
lipase = digest fat
proteases = digest protein

Question 21

How do fat-soluble vitamins enter circulation? Water-soluble?

Answer 21

fat-soluble = lymphatic system

water soluble = cardiovascular system

Question 22

The _______ empties into the ______ through the _______ sphincter between the
________.

Answer 22

the small intestine, large intestine, ileocecal valve, small & large intestine

Question 23

What reduces the number of beneficial bacteria?

Answer 23

antibiotics

Question 24

What are probiotics? Prebiotics? How do they help?

Answer 24

probiotics = bacteria & yeast
prebiotics = food for probiotics

control bacteria, synthesise vitamin K, aid in lactose digestion

Question 25

Describe what flatulence is. What causes it? How to help prevent it?

Answer 25

mixture of gases, fermentation of undigested bacteria in SI, prevented by increasing veg, lactose, fructose, sorbitol, fiber, or enzyme prep (Beano)

Question 26

Describe Inflammatory Bowel Diseases. What are the 2 disorders?

Answer 26

ulcerative colitis = inflammation & ulceration of innermost layer of LI
crohn’s disease = inflammation & ulceration of all layers & any part of the GI tract

Question 27

Describe Irritable Bowel Disease.

Answer 27

irregular bowel function & abdominal pain caused by abnormal intestinal motility