Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology for Pharmacy > GI 5: Regulation of Motility > Flashcards

GI 5: Regulation of Motility Flashcards

1
Q

____cells of the ___ are the electrical pacemakers of the GI tract

A

interstitial; cajal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

interstitial cells of the cajal are modified smooth muscle cells that don’t contract, but undergo _____

A

slow wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

do slow waves always reach threshold?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are slow waves?

A

undulating changes in resting membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

slow waves do not cause ______ by themselves, but set the _____

A

muscle contractions; maximal contraction frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what 4 things determine if slow wave threshold is met?

A
  1. stretch
  2. presence of food (chemo)
  3. parasympathetic stimulation
  4. hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

can you have more thresholds than slow waves?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

with decreased ap frequency, there is less influx of __ ions and decreased tone

A

ca

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

when slow waves are combined with excitatory signals , a __ is reached

A

threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

are ca channels slow or fast to open/close, means their ap last ___

A

slow; longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

slow waves w/o ap can only let ___ ions in, so contraction ___happen

A

na; can’t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are. the 3 contractile patterns

A
  1. peristalsis
  2. segmentation
  3. tonic contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is peristalsis and where does it occur?

A

smooth muscle activity where there is relaxation before the food blows and contraction behind it. Occurs along the entire GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

peristalsis results in the ___ of the bolus

A

forward movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is segmentation and where does it occur?

A

stationary contraction and relaxation of intestinal segments. occurs in the small and large intestines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

in segmentation, there is ___ net movement and results of ___ of the food bolus

A

no; mixing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is tonic contraction? where does it occur?

A

separation of structures and functions along the digestive tract. occurs at GI spinsters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

t/f there is very little forward movement in segmentation

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

t/f peristalsis is a polarized process

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

there is contraction ____cm behind the food bolus

A

2-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

ahead of the food bolus the is ___ relaxation

A

receptive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

when excited, the myenteric plexus increases what 4 things?

A
  1. tone of gut wall
  2. contraction intensity
  3. contraction frequency
  4. velocity of contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

cholecystokinin (CCk) secretion is stimulated by ____ , ___ and ___and is secreted from the ____ which moderately ____ stomach contractions

A

protein, fat, and acids; I cells of the duodenum, jejunum and ileum; inhibits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

glucose-dependent insulinotropic peptide is stimulated by ___, ___ and ___ and is secreted from the ___ cells of the ___ and ___ parts of the small intestine

A

fat, amino acids, carbohydrates; K; duodenum and jejunum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

the action of the glucose dependent insulinotropic peptide moderately ____ stomach contractions

A

inhibits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

motion secretion is stimulated by cyclic release during ____. It is secreted by the ____ cells of the ___ part of the small intestine

A

fasting; M ; duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

where does the voluntary stage of swallowing occur? what allows this area to act voluntarily?

A

mouth to pharnyx (made of skeletal muscle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what stage of swallowing is initiated by receptors in the pharynx, leading to soft palate and uvula elevation, epiglottis closing and relaxation of the esophageal spinster

A

pharyngeal (involuntary)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what are the 3 stages of swallowing

and are they voluntary / involuntary?

A
  1. voluntary (mouth to pharynx)
  2. pharyngeal (involuntary)
  3. esophageal (involuntary )
30
Q

the elevation of the soft palate during swallowing prevents ___

A

food getting into the nasal passageway

31
Q

what are the 3 types of motility involved in the esophageal stage of swallowing?

A
  1. primary peristalsis
  2. secondary peristalsis
  3. tonic contractions
32
Q

t/f peristaltic waves in the esophagus go the length of the esophagus

A

true

33
Q

primary peristalsis is a continuation of peristalsis waves form the ___

A

pharynx

34
Q

what happens in primary peristalsis?

A

food pushed down the esophagus

35
Q

how long does one wave take in primary peristalsis?

A

9 sec

36
Q

what is the stimuli for primary peristalsis?

A

pharynx distention

37
Q

secondary peristalsis is initiated by ___

A

esophagus distention

38
Q

secondary peristalsis only occurs if

A

primary wasn’t enough to get food to the stomach

39
Q

what are the 2 sphincters does the esophagus have?

A

upper and lower esophageal sphincters

40
Q

contraction of the upper esophageal sphincter reduces ___

A

air intake

41
Q

contraction of the lower esophageal sphincter reduces

A

acid reflux

42
Q

what is dysphagia?

A

difficulty swallowing

43
Q

dysphagia is often due to pathophysiology of the ___

A

esophagus

44
Q

dysphagia can be caused by ____, which is the loss of peristalsis in the lower esophagus and/or failure of the LES to relax and let bolus into the stomach

A

achalasia

45
Q

what is GERD?

A

increased frequency of LES opening, even w/o food bolus

46
Q

achalasia may be caused by the degeneration of neurons in the ____ plexus of the esophageal wall, especially the ___ neurons that induce relaxation of the LES

A

myenteric; inhibitory

47
Q

what are the 3 functions of the stomach?

A
  1. storage of large quantity of food
  2. mixing of food bolus with gastric juice
  3. slow, regulated emptying of chyme into the SM Int to improve digestion and absorption
48
Q

chyme

A

food mixed with GI secretions

49
Q

receptive relaxation allows the stomach volume to reach ___L is needed

A

1.5

50
Q

receptive relaxation occurs by the ___ reflex pathway, which is stimulated by the ___ of the stomach

A

vasovagal; distention

51
Q

what are the 3 parts of the stomach?

A

fundum, body, antrum

52
Q

regulated emptying in the stomach is caused by

A

peristalsis contractions in the antrum push chyme into the duodenum, but most of it is blocked by the pyloric sphincter so it is repulsed and mixed further

53
Q

gastric emptying requires what 2 things?

A
  1. increased peristalsis strength in the stomach

2. relaxation of the pyloric sphincter

54
Q

increased peristalsis strength in the stomach occurs mainly via inhibitory signals from the duodenum : (5)

A
  1. distention
  2. irritation
  3. chyme acidity
  4. chyme osmolarity
  5. protein breakdown products
55
Q

what are the 4 pathways for inhibitory signals of the duodenum to increase peristaltic strength in the stomach?

A
  1. enteric NS
  2. inhibitory SNS
  3. vagus nerve (PNS)
  4. hormones: CCK and GIP
56
Q

the max frequency of slow waves in segmentation if ___waves / per

A

12

57
Q

what are the 3 ways segmentation increases digestion and absorption??

A
  1. mixing of chyme
  2. minimal forward movement
  3. increase contact with the walls f the small intestine
58
Q

in the fed state, peristalsis in the small intestine is ___, having short and slow contractions

A

weak

59
Q

in the fed state, it takes ___hr(s) for chyme to pass from the pylorus to the ileocecal valve

A

3-5

60
Q

motility of the small intestine id stimulated by the distention of the ___ and __ and by the hormones ___, __ and __

A

small intestine and stomach; gastrin, CCK, motilin

61
Q

motility of the small intestine is inhibited by the hormones __

A

secretin

62
Q

what type of peristalsis occurs in the fasted state in the small intestine?

A

migrating motility complex (MMC), where undigested food is moved into the large intestine

63
Q

what is the function of migrating motility complex in the fasted state>

A

transport and cleaning

64
Q

what are the 2 types of movements in the large intestine?

A
  1. haustrations

2. mass movements

65
Q

what are haustrations and their function?

A

slow (2hr) large circular and longitudinal contractions to increase absorption of water and electrolytes (e.g. Na)

66
Q

where do haustrations occur in the large intestine/

A

ascending and transverse colon

67
Q

what are mass movements and their function?

A

sustained (10-30 min) peristaltic contractions that transport ,material from the transverse colon towards to rectum

68
Q

food in the stomach (____) and food in the duodenum (____) can lead to bowel movements

A

gastrocolic reflex; duodenocolic reflex

69
Q

give an example of an irritative colon disease

A

ulcerative colitis

70
Q

what are the pouches of the large intestine called?

A

haustrums

Physiology for Pharmacy (39 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions