Digestive System

Question 1

Intracellular digestion

Answer 1

Occurs within the cell, often membrane bound vesicles

Question 2

Extracellular digestion

Answer 2

Occurs outside of the cell, within lumen/tract

Question 3

Outline the pathway of food starting from oral cavity.

Answer 3

Oral cavity –> Pharynx –> Esophagus –> Stomach –> Small intestine –> Large intestine – Anus

Question 4

What type of digestion occurs in the mouth?

Answer 4

-Mechanical (mastication) and chemical (salivary amylase)

Question 5

Salivary amylase

Answer 5

-Breaks starch into maltose (disacc)

Question 6

Peristalsis

Answer 6

• Rhythmic waves of involuntary muscular contractions

- Esophagus

Question 7

What separate the stomach and esophagus?

Answer 7

-Lower esophageal (cardiac) sphincter

Question 8

Compare the relative pressure of the thoracic and abdominal cavities

Answer 8

• Thoracic cavity (where body of esophagus is) negatively pressured relative to environment on inhalation
• Abdominal cavity (+) pressure

Question 9

Gastroesphageal reflux disease (GERD)

Answer 9

• Results from pressure gradients

- Reflux of gastric material into esophagus

Question 10

What are chief cells?

Answer 10

• In gastric glands

- Produce pepsinogen

Question 11

What are parietal cells?

Answer 11

• In gastric glands

- Synthesize/release HCl and intrinsic factor (absorb vitamin B12)

Question 12

What is the role of HCl?

Answer 12

• Converts pepsinogen to pepsin

- Kills bacteria

Question 13

What kind of digestion is in stomach?

Answer 13

-Mechanical (churning) and Chemical

Question 14

Where does chyme pass into?

Answer 14

-Duodenum through pyloric sphincter

Question 15

What lines the stomach walls?

Answer 15

-Gastric mucosa secreted by mucous cells

Question 16

Where does chemical digestion finish?

Answer 16

-Small intestine

Question 17

What are the sections of the small intestine?

Answer 17

-Duodenum, Jejunum, Ileum

Question 18

What do villi consist of?

Answer 18

-Capillaries and lacteals

Question 19

Where do large fatty acids and glycerol go from the small intestine?

Answer 19

-Pass to lacteals then moved to liver where they’re converted to tryglycerides

Question 20

Which nutrients are actively absorbed?

Answer 20

-Amino acids and glucose

Question 21

Where does most digestion in small intestines occur?

Answer 21

-Duodenum

Question 22

What does intestinal mucosa secrete?

Answer 22

• Lipases
• Aminopeptidases
• Disaccharidases

Question 23

Where and what is the function of gastrin?

Answer 23

• Produced by G cells in duodenum
• Stimulate histamine and pepsinogen secretion
• Stimulate parietal cells

Question 24

Where and what is the function of intrinsic?

Answer 24

• Secreted by parietal cells

- Facilitate absorption of vitamin B12

Question 25

Cholecystokinin (CCK)

Answer 25

- Produced by I cells of duodenal/jejunal mucosa - Stimulate panreatic snzyme and somatostatin secretion - Stimulate gallbladder contraction - Hunger suppressant

Question 26

Secretin

Answer 26

- Synthesized by S cells of upper intestine - Stimulate secretion of bicarbonate-containing substances from pancreas - Inhibit gastric emptying and gastric acid production

Question 27

Bile

Answer 27

- Produced by liver and stored in gallbladder | - Release to small intestine to emulsify fats

Question 28

What is the purpose of emulsifying fats?

Answer 28

-Increase surface area for lipases

Question 29

What are functions of the liver?

Answer 29

- Store glycogen - Convert ammonia to urea - Protein synthesis - Detoxification - Cholesterol metabolism

Question 30

What does the pancreas produce?

Answer 30

- Amylase, trypsin, lipase | - Secrete bicarbonate containing substances

Question 31

Large intestine

Answer 31

-Absorb salt and any water not absorbed by small intestine

Question 32

Rectum

Answer 32

-Transient storage of feces --> anus