Digestive System

Question 1

Digestion

Answer 1

The degradation of large molecules into smaller molecules that can be absorbed into the bloodstream and used directly by cells

Question 2

Oral cavity

Answer 2

The mouth where mechanical and chemical digestion begins

Question 3

Mechanical disgestion

Answer 3

Breakdown of large food particles into smaller particles through physical actions or churning motion of the stomach

Question 4

Chemical digestion

Answer 4

The enzymatic breakdown of macromolecules into smaller molecules

Question 5

Saliva

Answer 5

Lubricates food to facilitate swallowing
Provides solvent for food
Contains amylase (ptyalin) which hydrolyzes starch to maltose

Question 6

Bolus

Answer 6

Food that has been moistened and chew enough to be swallowed

Question 7

Esophagus

Answer 7

The muscular tube leading from the mouth to the stomach

Question 8

Peristalsis

Answer 8

Involuntary muscular contractions that move food down the esophagus

Question 9

Lower esophageal (cardiac) sphincter

Answer 9

Muscular structure that contracts to close off the esophagus from the stomach

Question 10

Gastroesophageal reflux

Answer 10

The positive pressure of the abdominal cavity favours continual reflux of gastric materials into the negatively pressured esophagus
Reflux after spontaneous transient lower esophageal sphincter relaxations
Decreased lower esophageal sphincter pressure

Question 11

Stomach

Answer 11

A large, muscular organ located in the upper abdomen

Stores and partially digests food

Question 12

Gastric mucosa

Answer 12

A mucous membrane lining the stomach walls
Contain gastric glands
Muscous cells secrete mucus to protect the stomach lining from HCl

Question 13

Chief cells

Answer 13

Within the gastric glands

Synthesize pepsinogen, with HCl converts to pepsin and breaks down proteins

Question 14

Parietal cells

Answer 14

In gastric glands
Synthesize and release HCl
Kills bacteria
Release intrinsic factor for absorption of vitamin B12

Question 15

Chyme

Answer 15

Acidic, semifluid mixture of partially digested food produced by the mechanical and chemical digestion in the stomach

Question 16

Duodenum

Answer 16

First segment of the small intestine

Question 17

Small intestine

Answer 17

Duodenum, jejunum, ileum
Highly adapted to absorption
Extremely long (>6 meters) and highly coiled

Question 18

Villi

Answer 18

Finger-like projections extended out of the intestinal wall

Contain capillaries and lacteals

Question 19

Lipases

Answer 19

Digests fat

Question 20

Aminopeptidases

Answer 20

Digestion polypeptides

Question 21

Disaccharidases

Answer 21

Digest maltose, lactose, sucrose

Question 22

Gastrin

Answer 22

Produced in the G cells of the duodenum
Stimulate histamine and pepsinogen secretion
Increase gastric blood flow
Stimulate parietal cells to produce HCl

Question 23

Intrinsic factor

Answer 23

Secreted by parietal cells

Facilitate absorption of vitamin B12 across the intestinal lining

Question 24

Cholecystokinin (CCK)

Answer 24

Produced and stored in the I cells of the duodenal and jejunal mucosa
Stimulate pancreatic enzyme and somatostatin secretion
Stimulate gallbladder contraction
Hunger suppressant

Question 25

Secretin

Answer 25

Synthesized and stored in S cells of the upper intestine Stimulates secretion of bicarbonate-containing substances from the pancreas Inhibits gastric emptying and gastric acid production

Question 26

Liver

Answer 26

``` Produces bile Storages glycogen Converts ammonia to urea Protein synthesis Detoxification Cholesterol metabolism ```

Question 27

Bile

Answer 27

Produced in the liver Stored in the gallbladder Emulsifies fats from large globules into small droplets increasing surface area for pancreatic lipase

Question 28

Pancreas

Answer 28

Produces amylase, trypsin and lipase Releases chymotrypsin and enterokinase. Enterokinase cleaves trypsinogen to trypsin. Trypsin cleaves and actives other zymogens Secretes bicarbonate-rich juice to neutralize acidic chyme

Question 29

Zymogens

Answer 29

Enzyme precursors

Question 30

Large intestine

Answer 30

1.5 m long | Absorbs salts and water not already absorbed by the small intestine

Question 31

Rectum

Answer 31

Transient storage of feces before elimination through the anus