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Flashcards in Physiology Deck (45)
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1
Q

upper GI function

A

intake source and receptacle

initial digestion occurs

2
Q

middle GI function

A

site where most of digestion and absorption occurs

3
Q

lower GI tract function

A

storage channel for elimination of waste

4
Q

4 layers of of GI wall +fxn

A

inner mucosal

submucosal (support)

muscularis (peristalsis, circular layer, longitudinal layer)

outer serosa

5
Q

types of muscle contractions

A
mass movements 
tonic contractile 
phasic contractile 
segementing
haustral
6
Q

peristalsis contractile activity

A

serves to propel forward food

7
Q

mass movements

A

propulsive movement of unit within large intestine

8
Q

tonic contractile activity

A

found between two organs, stable contraction

occludes lumen

typically in LES, UES, other sphincter

9
Q

phasic contractile activity

A

periodic contraction

lasts few seconds and followed by relaxation

10
Q

segmenting contractions

A

mix chyme with secretions and bring contents into contact with mucosa for digestion and absorption

11
Q

haustral contractions

A

segmenting contraction with longer duration

12
Q

components of enteric nervous system

A

myenteric plexus

submucosal plexus

13
Q

myenteric plexus

A

aka Auerbach

between circular and longitudinal calls

concerned with motility

14
Q

submucosal plexus

A

AKA Meissner

controlling function of ea. segment of intestinal tract

15
Q

SNS effect on GI tract

A

via thoracocolumbar spinal cord

stimulation cause decrease in activity + decreased motility and secretions

16
Q

PNS effect on GI tract

A

via vagus nerve

cause increase in activity including increased motility and secretions

17
Q

areas of striated muscle in GI

A

pharynx, upper third of esophagus, external anal sphincter

18
Q

increased smooth muscle ocontraciotn when

A

PNS stimulation

stretching smooth muscle (gas or constipation)

19
Q

decreased excitability of smooth muscle contraction

A

SNS stimulation

20
Q

achalasia and neuromuscular

A

LES does not rely

21
Q

Hirschsprung dz and neuromuscular

A

lack of inhibitory enteric n. in colon

22
Q

ileus and neuromuscular

A

caused by trauma or infection + disruption of normal neuro hormonal regulation

23
Q

IBS and neuromuscular

A

altered sensory nerve fxn or altered motility

24
Q

involuntary motor impulses for oral and pharyngeal phases carried in: 4

A
  1. trigeminal (V)
  2. Glossopharyngeal (IX)
  3. Vagus (X)
  4. hypoglossal (XII)
25
Q

impulses for esophageal phase are carried in

A

vagus (X)

26
Q

rectosphinteric reflex

A

responsible for defecation

contents cause relaxation of internal anal sphincter and urge to defecate occurs

27
Q

functions of saliva

A
  1. protection and lubrication
  2. protective antimicrobial action
  3. initiate digestion of starches
28
Q

salvia produced and secreted by

A

parotid, submaxillary, sublingual and buccal glands

29
Q

gastric secretion (cells) (4)

A

mucous secreting cells
parietal cells
cheif cells
G sells

30
Q

mucous secreting cells

A

barrier of protection

31
Q

parietal cells

A

HCl and IF (b12)

32
Q

chief cells

A

pepsinogen (converted to Pepsi when exposed to low pH)

33
Q

G cells

A

secrete gastrin

stimulates gastric acid and pepsinogen, increased gastric blood flow, stimulate scontraction, growth of gastric and intestinal mucosal cells

34
Q

functions fo secretory glands

A

mucous production (lubricate, protect)

secrete fluids and enzymes (digestion of nutrients)

35
Q

GI hormones

A

cholecystokinin
gastrin
secretin

36
Q

cholecystokinin

A

stim cox of GB

secretion of enzymes, slows gastric emptying, decreases food intake

37
Q

gastrin

A

stimulates secretion of gastric acid and pepsinogen

increases gastric blood flow, simulates gastric smooth muscle and stimulates growth of gastric and intestinal cells

38
Q

secretin

A

stimulates secretion of bicarbonate

contains fluids by pancreatic and liver

39
Q

secretions of small intstine

A

bruners glands (alkaline mucous)

secretion 2

secretion 3 (enzymes peptidases and disaccharidases)

40
Q

functions of gut flora

A

metabolic activity (fermentation of indigestible)

trophic effects /grooming

protection

colonization

41
Q

when does colonization take place?

A

begins shortly after birth

influenced by passage thru birth canal and others

42
Q

digestion

A

dismantling food into constituent parts

43
Q

processes of digestion

A

hydrolysis
enzyme cleavage
fat emulsification

44
Q

absorption

A

process of moving food into the internal environment

active transport and diffusion

45
Q

fxn of intestinal brush border

A

aid in digestion of carbs and proteins

adhere to border of villous structure