GI 3 Post midterm

Question 1

3 Functions of Stomach

Answer 1

Storage: Stores food and regulates its passage into the small intestine
Digestion: Chemical and Mechanical digestion into Chyme
Defense: Destroys bacteria and other pathogens in food and pathogens trapped in airway mucus

Question 2

Where is motility and secretion initiated

Answer 2

Cephalic Stage

Question 3

What occurs upon swallowing food

Answer 3

Parasympathetic neurons to the ENS cause the funded of the stomach to relax: Receptive Relaxation

Makes room for food coming in

Question 4

Distention of stomach enhances _________

Answer 4

Motility

Question 5

Propulsion

Answer 5

Propels food toward the pylorus

Question 6

Retropulsioon

Answer 6

Larger particles are moved back to the body

Question 7

G cells

Answer 7

Secretes gastrin in response to amino acids, peptides and distension (Short reflex - GRP)

Question 8

When is gastrin stimulated

Answer 8

By ENS during cephalic phase (Parasympathetic input)

Question 9

Role of gastrin

Answer 9

Acid secretion DIRECTLY from parietal cells

Question 10

Indirect role on gastrin

Answer 10

Stimulates histamine release and that stimulates parietal cells

Question 11

Parital cells

Answer 11

Secrete gastric acid
Stimulated from Fastrin
Histamine from ECL
Ash from ENS neurons via long reflex functions

Question 12

Gastric acid functions

Answer 12

• Stimulates release of pepsinogen from chief cells, cleaves pepsinogen to pepsin (Digests proteins)
• Denatures proteins make it easier for pepsin to function
• Kills bacteria and other ingested microorganisms
• Inactivates amylase from saliva
• Stimulated D cells to release somatostatin (Break in Acid Secretion)