Karius

Question 1

ACh, NE, VIP, Enkephalins (opiates) are all what?Be careful of which bc results in what SE when used for pain management?

Answer 1

• all GI NT

Enkephalins - constipation

Question 2

Gastrin

• stimulus for secretion
• site of secretion
• actions

Answer 2

• distention of stomach, Vagus
• secreted from G cells in stomach
• action - increase gastric acid

Question 3

Cholecystokinin (CCK)-

• stimulus for secretion
• site of secretion
• ACTIONS(5)**

Answer 3

-aa, peptides, FA
-I cells of duodenum and jejunum
- Fat absorption
1) **GB cxn
2) **Increase pancreatic enzyme secretion
3) Increase pancreatic bicarb secretion
4) growth of exocrine pancreas an dGB
5)decreases GASTRIC EMPTYING/inc emptying time
(also acts on brain/liver to cause satiety)

Question 4

Secretin:

• stimulus for secretion
• site of secretion
• actions

Answer 4

• Acid or FA in duodenum
• S cells of duodenum
• increase pancreatic bicarb, increased biliary bicarb, dec. gastric acid secretion

Question 5

Glucose-dependent Insulinotropic Peptide (GIP):

• stimulus for secretion
• site of secretion
• actions

Answer 5

• FA, aa, oral glucose
• duod/jejunum
• inc insulin from pancreatic B cells, dec gastric acid secretion

Question 6

Pancreatic enzymes:

Answer 6

• somatostatin (D cells) –> when luminal pH decreased to dec. acid
• histamine - stimulate acid

Question 7

Where is the satiety center located?

Answer 7

VPN - ventromedial nucleus of the hypoth

Question 8

Where is the feeding center located? Where does the incoming info come from?

Answer 8

LHA - lateral hypothalamic area.

Info comes from the Arcuate Nucleus of the hypothalmus

Question 9

What is released from the arcuate nucleus to DECREASE appetite. What substances act on arcuate nucleus to cause this.

Answer 9

Anorexigenic Neurons release POMC to dec appetite.
-Release stimulated by LEPTIN, insulin, GLP-1

CCK also acts on brain/liver to cause satiety

Question 10

What is released from the arcuate nucleus to INCREASE appetite. What substances act on arcuate nucleus to cause this.

Answer 10

Orexgenic Neurons release neuropeptide Y to inc appetite.

-Release of GHRELIN by gastrin cells.

Question 11

Where is the vomiting center? Afferent info comes from what 4 locations?

Answer 11

Medulla –> NUCLEUS TRACTUS SOLITARIUS (also pharyngeal swallow coordination center)
Info comes from: vstibular system, back of throat, GI, and CTZ

Question 12

The sequence of the vomiting reflex:

Answer 12

VOMITING:

1. Rerverse peristalsis
2. relaxation of the stomach and pylorus
3. forced inspiration to inc abd pressure
4. mvmt of larynx upward and forward and RELAXATION of LES
5. glottis closure
6. forceful expulsion of gastric –> UES OPEN

RETCHING - UES CLOSED, LES open (gastric contents stay in stomach

Question 13

GI secretions from the saliva.

• Names
• Factors that increases secretion
• Factors that decrease secretion

Answer 13

• bicarb, potassium, amylase, lipase
• PSNS(major), SNS
• sleep, dehydration, atropine

Question 14

GI secretions from the Stomach (2)

• Names
• Factors that increases secretion
• Factors that decrease secretion

Answer 14

• HCl (stim by GASTRIN, ACh, HISTAMINE; dec. by acid, chyme in duod, somatostatin, atropine, cimetidine, omeprazole)
• Pepsinogen factor (stim by PSNS)

Question 15

GI secretions from the Pancrease (2).

• Names
• Factors that increases secretion

Answer 15

• Bicarb (inc by secretin, CCK, PSNS)

- Pancreatic lipase/amylase/proteases (inc. by CCK and PSNS)

Question 16

GI secretions from the Stomach (4)

• Names
• Factors that increases secretion (same for all 4)
• Factors that decrease secretion (same for all 4)

Answer 16

• Bile salts, Bilirubin, Phospholipids, cholesterol
• inc. by CCK (GB cxn, Oddi relaxation), PSNS
• dec. by ileal resection

Question 17

Mechanism of HCl secretion by parietal cells: basolateral membrane exchangers and apical membrane channels.
-omeprazole affects what?

Answer 17

• Basolateral exchangers: Na/K ATPase, HCO3/Cl exchangers

- Apical channels - H/K ATPase and Cl channels

Question 18

Digestion and absorption of carbohydrates

Answer 18

Location of absorption: SI

Digestion: Salivary and Pancreatic amylase, SI sucr/malt/lact/trehalASE

Question 19

Digestion and absorption of proteins

Answer 19

Location of absorption: SI

Digestion: Stomach pepsin, pancreatic typsin, chymotryp, carboxypeptidase, elastase, SI dipeptidase/enterokinase

Question 20

Digestion and absorption of lipids

Answer 20

Location - SI

Digestion - lingual lipase. pancreatic lipase-colipase, PLA2, cholesterol ester hydrolase

Question 21

Diarrhea due to increased motility - 2 ways

Answer 21

1. Peristaltic rush - SI irritation, clears irritant. SUBSTANCE P binds to NK-1 receptor
2. Ultrapropulsive event - irritation in LI, clears irritant. NEUROKININ B binds to NK3 receptor

Question 22

What triggers production of bile salts/acids?

Answer 22

Return of bile salts/acids to liver.

Question 23

Relaxation of hepatopancreatic sphincter of Oddi is produced by?

Answer 23

Wave of relaxation that precedes a peristaltic wave in duodenum

Question 24

Widened, flattened villi on biopsy associated with what type of diarrhea?

Answer 24

Osmotic

Question 25

Pharyngeal phase of swallow is coordinated by…?

What 2 other things does this center do?

Answer 25

Nucleus of the solitary Tract (NTS) (also vomiting center)

- Also vomiting center and terminates inspiration

Question 26

What is the major inhibitory NT of enteric NS? Necessary for what?

Answer 26

Nitric Oxide, necessary for relaxation - absent in hirschsprung and achalasia

Question 27

Gastric acid secretion REDUCTION and INCREASE in gastric mucus?

Answer 27

PGE2 (i.e. aspirin disrupts)

Question 28

Analong of what can be administered to decrease acid secretion?

Answer 28

somatostatin

Question 29

What cells release intrinsic factor?

Answer 29

G cells (stomach)