The Enteric Nervous System Flashcards
1
Q
What is innervated by ENS?
A
- GIT (oesophagus to rectum)
- Pancreas and biliary system
2
Q
2 major plexuses of ganglion cells and fibre bundles and where they are found
A
- Submucosal plexus (stomach and intestines)
- Myenteric plexus (full length of GIT)
3
Q
At what layer are the 2 major plexuses found?
A
- Submucosal under circular muscle
- Myenteric under longitudinal muscle
4
Q
Types of neurones in ENS
A
- Afferent neurones (mechanoreceptors and chemoreceptors)
- Interneurones (excitatory and inhibitory)
- Efferent neurones (excitatory and inhibitory)
- Effectors (motor and secretory)
5
Q
What do enteric reflexes do?
A
- Motor reflex
- Secretory reflex
- Blood flow
6
Q
What plexus(es) control(s) motor reflex?
A
Myenteric
7
Q
What plexus(es) control(s) secretory reflex?
A
Submucosal
8
Q
What plexus(es) control(s) blood flow?
A
Myenteric and submucosal
9
Q
ENS-specific diseases/dysfunctions
A
- Chaga’s disease
- Achalasia (oesophagus nerve damage)
- Hirschsprung’s disease
10
Q
What causes Chaga’s?
A
Trypanosome parasite releasing a toxin that leads to neurone death
11
Q
What causes Hirschsprung’s?
A
Congenital absence of ENS neurones
12
Q
Symptoms of Hirschsprung’s and their causes
A
- Abnormal defaecation (no rectoanal reflex)
- Colitis (peristaltic wave halts)
13
Q
General neurological conditions affecting enteric nervous system
A
- Parkinson’s disease
- Peripheral neuropathies
- Myasthenia Gravis
14
Q
What causes irritable bowel syndrome?
A
Dysfunctional interaction between CNS and ENS
