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Flashcards in GI 1 Deck (109)
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1
Q

inhibitory hormones for small bowel peristalsis

A

secretin and glucagon

1
Q

caused by intense irritation of intestinal mucosa; involves ANS, brainstem, myenteric plexus (long distances of small bowel covered in minutes)

A

peristaltic rush

2
Q

stimulates gastric acid secretion and gastric mucosal growth

A

gastrin

2
Q

mediates feedback control of ileocecal sphincter (intensifies when cecum is distended)

A

myenteric plexus and prevertebral symp ganglia

2
Q

what pyrloic glands secrete

A

mucous and gastrin

2
Q

colonoileal reflex is important for this

A

inhibits ileal release

3
Q

what Ach stimulates secretion of

A

pepsinogen, HCl, mucous

3
Q

how much bile salts produced per day

A

6 gm

3
Q

sympathetic inhibits or activates mucous protection/secretion?

A

inhibits

4
Q

frequency of normal small bowel contractions (less than this number typically)

A

12/min

4
Q

intensifies peristalsis in ileum (immediately after meal), empties ileal contents into cecum

A

gastroileal reflex

5
Q

where most bile salts are reabsorbed

A

terminal ileum

5
Q

where secretin is produced

A

S cells duodenum

5
Q

occurs during distension of small bowel, acid in upper small bowel, protein breakdown products, or irritation of mucosa (inhibits gastric secretion)

A

reverse enterogastric reflex

5
Q

actually excite the muscle contraction; complex interactions among SMC and interstitial cells of Cajal

A

spike wave

6
Q

in proximal duodenum…part of small bowel secretion

A

Brunner’s glands

6
Q

pits in small intestine (line surface area)

A

crypts of lieberkuhn

7
Q

works to neutralize the HCl emptied into the duodenum from the stomach

A

HCO3

9
Q

amount of bile produced per day

A

600-1000 mL

11
Q

ions present in saliva

A

K, bicarbonate, Na, Cl

11
Q

responsible for bile acid secretion

A

secretin

12
Q

GI glands release this for vasodilation

A

kallidin and bradykinin

12
Q

small bowel digestive enzymes (6)

A

peptidase, sucrase, maltase, isomaltase, lactase, intestinal lipase

13
Q

absorbed at terminal ileum

A

bile acids and folate

14
Q

released by parasym…excites secretion of pepsinogen, HCl, and mucous

A

acetylcholine

16
Q

where cholecystokinen is produced

A

I cells duodenum/jejunum

16
Q

enteric NS plexus located between longitudinal and circular muscle layers

A

myenteric/Auerbach’s plexus

17
Q

cranial nerves that transmit information from reticular substance medulla/pons for swallowing

A

V, IX, X, XII

18
Q

three stages of swallowing

A

voluntary, pharyngeal, esophageal

18
Q

enzyme that splits fatty acid from phospholipids (pancreatic secretion)

A

phospholipase

18
Q

what temporarily stores 1/2 to 3/4 of nutrients

A

liver sinusoids

19
Q

what makes up most gallstones

A

cholesterol

20
Q

branch of NS that promotes propulsion

A

parasym

21
Q

hormones that act as vasodilator substances to increase splanchnic blood flow (4)

A

CCK

vasoactive intestinal peptide

gastrin

secretin

22
Q

where enterochromaffin like cells located

A

in the recesses of oxyntic glands

(or fundic/gastric glands)

23
Q

inhibits gastric acid secretion in duodenum; promote pancreatic secretion of bicarbonate (to neutralize acid)

A

secretin

25
Q

what intrinsic factor is necessary for (activated by HCl)

A

absorption B12

26
Q

how much HCl per L of gastric juice

A

160 mmol

26
Q

final secretion from canaliculus includes these substances

A

water, HCl, KCl, NaCl

27
Q

what ptyalin digests

A

starch

27
Q

what tubular glands secrete (in stomach and upper duodenum)

A

pepsinogen and acid

28
Q

how long mass movements usually persist

A

10-30 min

29
Q

where gastrin is released

A

G cells

31
Q

where tubular glands are located

A

stomach and upper duodenum

33
Q

amount of chyme that empties into cecum per day

A

1500-2000 mL

34
Q

transmits wave of relaxation preceding peristalsis

A

myenteric inhibitory neurons

36
Q

from stomach and colon..inhibits gastric motility and secretion

A

enterogastric reflex

37
Q

remove bacteria and harmful matter from splanchnic circulation

A

reticuloendothelial cells

38
Q

promotes UGI motility

A

motilin

39
Q

inhibits increased stomach motility caused by gastrin

A

CCK

39
Q

principal glands for salivation

A

parotid, submandibular, sublingual, buccal

40
Q

micelles of bile salts aid in absorption of these

A

fatty acids, monoglycerides, cholesterol, other lipids

41
Q

calories consumer per liter of gastric juice produced

A

1500

43
Q

cells that make up oxyntic gastric glands

A

mucous neck cells, peptic/chief cells, parietal/oxyntic cells

45
Q

what oxyntic glands secrete

A

HCl, pepsinogen, intrinsic factor, mucus

46
Q

stimulate pancreatic digestive enzymes

A

Ach and CCK

48
Q

stimulates gallbladder emptying; inhibits gastric contraction; and possibly inhibits hunger (respond to fats, FA, monoglycerides)

A

CCK

49
Q

factors in the saliva that destroy bacteria

A

thiocyanate ions, proteolytic enzymes/lysozyme

50
Q

reflex involved in gastric phase of gastric secretion

A

vasovagal

52
Q

function of proximal colon

A

absorption of water and electrolytes

53
Q

drug that will weaken segmented contractions (by blocking excitatory activity of enteric NS)

A

atropine

54
Q

located between the intestinal vili; contain goblet cells and enterocytes

A

Crypts of Lieberkuhn

55
Q

where H. pylori is typically located

A

antrum

56
Q

what goblet cells secret in Crypts of Lieberkuhn

A

mucus

58
Q

small bowel digestive enzyme important for splitting neutral fats into glycerol and FA

A

lipase

58
Q

enteric NS plexus that controls GI movements; increased tone, intensity of contraction, rate of rhythm, velocity of conduction

A

myenteric

60
Q

slow closing/opening channels in GI muscle fibers responsible for action potentials

A

Ca/Na channel

62
Q

important in “mass movements”; 20 cm distal to this point lose haustrations and contract as one unit, propelling feces (lasts 30 sec…relax for 2-3 min)

A

constrictive ring

63
Q

what produces gastrin?

A

G cells

(in antrum of stomach)

64
Q

intraluminal pressure of lower esophagus

A

30 mmHg

66
Q

inhibits gastric motility; stimulates secretion of insulin by the pancreas

A

GIP

67
Q

enteric NS plexus located in submucosa; receives signals about what should be done

A

submucosal/Meissner’s

68
Q

hormones that inhibit gastric secretion

A

secretin, gastric inhibitory factor, vasoactive intestinal polypeptide, somatostatin

70
Q

3 routs that food in duodenum increases pyloric sphincter tone

A

enteric NS, extrinsic n to prevertebral ganglia, vagus/brainstem

71
Q

where sensory nerve endings in GI epithelium send their afferent fibers

A

enteric plexuses, prevertebral ganglia sympathetic, spinal cord, vagus nerves

72
Q

direct release of HCl is directly dependent on the amount of this secreted

A

histamine

73
Q

enteric NS plexus that controls GI secretion and local blood flow; intestinal secretion, absorption, contraction that causes infolding of mucosa

A

submucosal

75
Q

length of primary peristalsis

A

6-10 sec

76
Q

splits small peptides into amino acids (small bowel digestive enzyme)

A

peptidase

78
Q

performs hydrolysis of cholesterol esters (pancreatic secretion)

A

cholesterol esterase

79
Q

hormone that reduces blood flow to splanchnic system

A

somatostatin

80
Q

GI hormone that is important in small bowel secretion

A

secretin

81
Q

function of distal colon

A

storage fecal matter

82
Q

strongly stimulate secretion of acid by parietal cells

A

gastrin and histamine

84
Q

activates trypsin; secreted by intestinal mucosa when exposed to chyme

A

enterokinase

85
Q

NS responsible for reverse enterogastric reflex

A

myenteric NS, extrinsic sym and vagus

86
Q

cells that secrete histamine

A

enterochromaffin-like cells

87
Q

most potent emptying of gallbladder

A

CCK

88
Q

protein present in mucus secretion (lubricates and protects surface)

A

mucin

89
Q

enzyme that catalyzes conversion of OH- to form CO2

A

carbonic anhydrase

90
Q

reflexes that facilitate mass movements

A

gastrocolic and duodenocolic

91
Q

what parietal cells secrete

A

HCl

92
Q

pH of stomach due to HCl acid secretion

A

0.8

94
Q

rate of movement for small bowel peristalsis (3-5 hours transit)

A

1 cm/min

95
Q

fluid and dissolved substances are absorbed until this amount of feces are expelled (important for diagnosis diarrhea)

A

80-200 mL

96
Q

usual stimulus for intestinal peristalis

A

distension of gut

97
Q

threshold for spike wave

A

-40

98
Q

length of GI spike (time)…10-40x longer than nerve fiber; 1-10 spikes per second

A

10-20 msec

99
Q

more abundant form of gastrin

A

G17

100
Q

enzyme that hydrolyzes neutral fat into fatty acids and monoglycerides (pancreatic secretion)

A

pancreatic lipase

101
Q

sensory cranial nerves involved in initiating pharyngeal stage of swallowing

A

V and IX

102
Q

stimulates secretion of histamine

A

gastrin

103
Q

stimulates gastric HCl secretion

A

gastrin

104
Q

reflex for evacuation

A

gastrocolic reflex

105
Q

alpha-amylase that is present in serous secretion

A

ptyalin

106
Q

cells in crypts of Lieberkuhn that secrete water and electrolytes; also absorb water, electrolytes, nutrients

A

enterocytes

107
Q

where motilin is secreted (during fasting)

A

stomach and duodenum

108
Q

regulates small intestine secretion (NS)

A

local enteric nervous reflexes

109
Q

what pancreatic amylase breaks down

A

starch, glycogen, CHO