Intro to GI and Esophageal Motility Module (Quiz)

Question 1

GI tract innervated by which nervous system

Answer 1

• autonomic

Question 2

autonomic nervous system divided into

Answer 2

• extrinsic

- enteric

Question 3

extrinsic nervous system divided into

Answer 3

• parasympathetic

- sympathetic

Question 4

the enteric nervous system is connected to the

but can function

Answer 4

• CNS

- can also function autonomously

Question 5

two networks for the enteric nervous system

Answer 5

• myenteric plexus

- submucousal plexus

Question 6

which plexus is located between the outer longitudinal and middle circular muscle layers

Answer 6

• myenteric plexus

Question 7

which plexus is located between the middle circular layer and the mucosa

Answer 7

• submucousal plexus

Question 8

which plexus controls motor function of the longitudinal and circular smooth muscle layers

Answer 8

• myenteric plexus

Question 9

which plexus controls intestinal secretion

Answer 9

• submucous plexus

Question 10

in the ______ plexus, excitatory motor neurons stimulate smooth muscle contraction primarily through release of _________ and inhibitory motor neurons stimulate relaxation primarily though release of _________

Answer 10

• myenteric plexus
• excitatory - acetylcholine
• inhibitory - nitric oxide

Question 11

the __________ plexus innervates the glandular epithelia, intestinal endocrine cells, and submucosal blood vessels to regulate intestinal secretion

Answer 11

• submucousal plexus

Question 12

parasympathetic innervation of the GI tract is supplied primarily by which nerves

Answer 12

• vagus nerve

- pelvic nerves

Question 13

preganglioninc efferent parasympathetic fibers project to the cholinergic neurons within the myenteric and submucous plexuses of the enteric nervous system to cause smooth muscle ___________

Answer 13

• contraction

Question 14

the preganglionic vagal fibers project to enteric neurons where

Answer 14

• esophagus
• stomach
• small intestine
• colon

Question 15

efferent fibers in the pelvic nerves project to enteric neurons where

Answer 15

• colon

- rectum

Question 16

vagal nerve signals are primarily mediated through the release of

Answer 16

• acetylcholine

Question 17

parasympathetic inputs in the esophagus and stomach result in contraction or relaxation?

Answer 17

• both

- controls excitatory or inhibitory motor neurons

Question 18

parasympathetic projections to the small and large intestine result in contraction or relaxation?

Answer 18

• contraction

- controls excitatory motor neurons

Question 19

sympathetic input in the enteric nervous system does what

Answer 19

• shunt blood from splanchnic to systemic circulation

- suppress digestive function

Question 20

sympathetic input mediated primarily through which neurotransmitter

Answer 20

• norepinephrine

Question 21

sympathetic input acts directly on sphincteric muscles to ________ tone, keep the sphincter ________ and ________ GI motility through presynaptic _________ of enteric motor neurons

Answer 21

• increase tone
• keep sphincter closed
• decrease GI motility
• through presynaptic inhibition

Question 22

peristalsis is an organized reflex response initiated when

Answer 22

• gut wall stretched by luminal contents

Question 23

wall stretch initiates ________ of the circular muscle and ________ of the longitudinal muscle in the propulsive segment

Answer 23

• contraction of circular muscle

- relaxation of longitudinal muscle

Question 24

wall stretch initiates ________ of the circular muscle and ________ of the longitudinal muscle in the receiving segment

Answer 24

• relaxation of circular muscle

- contraction of longitudinal muscle

Question 25

wave of perastalsis moves in an _____ to _____ direction

Answer 25

- oral to caudal

Question 26

while peristaltic activity can be increased or decreased by the parasympathetic and sympathetic stimuli its occurrence is ________ of extrinsic innervation

Answer 26

- independent of

Question 27

what is trituration purpose

Answer 27

- crushing and grinding ingested food by the stomach | - decreases particle size and increases surface area to improve efficiency of digestive enzymes in the small intestine

Question 28

what do mixing movements do

Answer 28

- blend secretions with nutrients in the small intestine to promote increased contact with mucosal surface to facilitate nutrient absorption

Question 29

the prototypic mixing pattern is termed

Answer 29

- segmentation

Question 30

prototypic mixing movement involves a repetitive pattern of ___________ propulsion into _______ receiving segments that facilitate stirring and mixing of chyme

Answer 30

- repetitive pattern of bidirectional propulsion into relaxed receiving segments

Question 31

reservoir functions are performed by

Answer 31

- stomach and colon

Question 32

which sphincter is located at the junction of the posterior oropharynx and proximal esophagus

Answer 32

- upper esophageal sphincter

Question 33

function of upper esophageal sphincter

Answer 33

- prevents retrograde flow of GI contents | - prevents passage of air into esophagus

Question 34

which sphincter is located at the junction of the distal esophagus and proximal stomach

Answer 34

- lower esophageal sphincter

Question 35

function of lower esophageal sphincter

Answer 35

- prevents reflux of gastric contents into esophagus

Question 36

in the absence of a hiatal hernia, the lower esophageal sphincter is located in the

Answer 36

- diaphragmatic hiatus

Question 37

what is located at the junction of the distal stomach and duodenal bulb

Answer 37

- pylorus

Question 38

function of pylorus

Answer 38

- gastric emptying | - prevents reflux of bile acid and pancreatic enzymes into the stomach

Question 39

which sphincter is located at the level of the duodenal ampulla where both the pancreatic and common bile ducts insert in the duodenum

Answer 39

- sphincter of Oddi

Question 40

function of sphincter of Oddi

Answer 40

- prevents reflux of small bowel chyme into bile and pancreatic ducts - participates in maintenance of sterility of pancreatic and biliary trees

Question 41

which sphincter is located at the junction of the terminal ileum and cecum

Answer 41

- ileocecal valve

Question 42

function of ileocecal valve

Answer 42

- prevents reflux of colonic contents into small bowel | - limits small bowel bacterial overgrowth

Question 43

which sphincters are located at the proximal and distal aspects of the anal canal

Answer 43

- internal and external anal sphincters

Question 44

function of internal and external anal sphincters

Answer 44

- maintain fecal continence

Question 45

division of esophagus

Answer 45

- upper esophageal sphincter - esophageal body - lower esophageal sphincter

Question 46

proximal 1/3 of esophagus composed of ________ muscle distal 2/3 of esophagus composed of _______ muscle

Answer 46

- striated | - smooth

Question 47

the upper and lower esophogeal sphincters remain ________ which ________ influx of air and reflux of gastric contents into esophagus while the esophageal body is _________ when not involved in the act of _________

Answer 47

- sphincters remain contracted - prevents influx of air - esophageal body is relaxed - when not involved in swallowing

Question 48

primarily peristalsis is initiated by

Answer 48

- voluntary act of swallowing

Question 49

secondary peristalsis occurs when

Answer 49

- primary peristaltic event fails to clear bolus from body of esophagus

Question 50

secondary peristalsis initiated by action of

Answer 50

- mechanoreceptors

Question 51

at the onset of the swallow, the lower esophageal sphincter ________ which corresponds to a ________ in pressure across the sphincter which lasts until what is this also called

Answer 51

- relaxes - fall in pressure - lasts until esophagus empties its contents into the stomach - deglutitive relaxation of the LES

Question 52

coordination of the peristaltic wave and relaxation of the lower esophageal sphincter is mediated by ______ nerve signals

Answer 52

- mediated by vagal nerve signals