ENS Flashcards
What parts of the nervous system does tobacco perturb? What does atropine do?
Tob: both parts of ANS and voluntary motor
At: blocks mAChR
From where do preganglionic neurons get input?
PFC, amygdala, hypothalamus, brainstem
In what parts of the gut are myenteric and submucosal plexuses found?
M: entire length
S: intestine to rectum
Where do myenteric and submucosal plexuses project to?
M: external muscles and submucosal plexus
S: myenteric plexus, mucosa, etc.
What are the functions of myenteric and submucosal plexuses?
M: motility, peristalsis
S: most mucosal fxn, secretomotor, sensory, immune
What is cause and symptoms of Hirschsprung’s disease?
Distal absence myenteric and submucosal plexuses, obstruction distal colon, distention
What types of NTs are in ENS, and why is this important?
ACh, monoamines, peptide (VIP), endocannabinoids, gases (NO). Rx’s affect: dec motility, increase risk impaction
How does the SNS affect the gut?
Decreased sphincter motility, blood flow, acid secretion. Affects immunity.
What is postoperative ileus?
Decreased motility following surgery causing nausea/vomiting, distention, linked to increased SNS, meds
How does stress affect the gut?
Decreases gastric motility, increases colon motility (not SNS)
Where does PSNS innervate gut?
Focused on myenteric plexus
What are command neurons?
Receive input from PSNS, project to “local preprogrammed circuits”
How is defecation affected by SCI?
Sacral cord: loss
Above S2,3,4: reflex intact, but difficulty sensing bowel fullness and defecating
What is the vago-vagal reflex?
Dietary carbs, lipids, proteins fire vagal viscerosensory fibers -> NTSol -> DMNX -> vagal pregang PS -> decrease gastric emptying
What are DRG viscerosensory fibers important for?
Bowel/bladder sensory input to cord
