Regulstion of gut Flashcards
What is the enteric nervous system?
Intrinsic nervous system
- wall of the GI tract contains millions of neurons
- independently controls GI
- integrates motor and secretory activities of GI
What might arise as a result of enteric dysfunction?
What might cause it?
Inflammation
Irritable bowel syndrome
Post-operative injury
Ageing
What does the enteric nervous system regulate?
Motility
Blood flow
Water and electrolyte transport
Secretion
Absorption
Which neurons are used?
Standard
- Sensory
- Motor
- Interneurons
- Decides magnitude of stimulus - not just a refluex
Where are the main nerve plexuses located?
Cuts through layers
- Myenteric plexus
- between longitudinal and circular muscle
- for gut motor function
- between longitudinal and circular muscle
- Submucosal plexus
- underneath epithelia
- for epithelial, blood flow and endocrine function
- underneath epithelia
- Deep muscular plexus
- in the circular muscle
What does the autonomic nervous system regulate?
Smooth muscle, cardiac muscle and glands
How are the foregut and midgut sympathetically innervated?
Thoracic splanchnic nerves
How is the hindgut sympathetically innervated?
Lumbar splanchnic nerves
What is the point of sympathetic nerve activation?
Inhibit GI system activity
How are the foregut and midgut parasympathetically innervated?
Cranial nerves
How is the hindgut sympathetically innervated?
Pelvic nerves
What are the main autonomic neurotransmitters?
NA - symp
ACh - para
How does the autonomic nervous system interact with the GI?
Synapses to myenteric plexuses via enteric system
What is the point of parasympathetic nerve activation?
Stimulate GI activity
WHat is intramural plexus?
Intramural plexus
- plexus found in ENS
