Control Of Gut Nerves Flashcards
What is a ganglion?
Collection of cell bodies exist in outside of the CNS
How do the lengths of the pre nd post ganglionic neurones differ in the parasympathetic and sympathetic nervous system?
Parasympathetic = long preganglionic and short postganglionic
Sympathetic = short Preganglionic and long postganglionic
What type of outflow is the parasympathetic nervous system?
What does this mean?
Craniosacral outflow
Innervation from cranial nerves and pelvic nerves (S2, S3 and S4)
What is the main nerve of the parasympathetic nervous system involved in Craniosacral outflow?
Vagus nerve
What is the type of outflow called from the sympathetic nervous system?
What nerve levels is this for the whole body?
What nerve level is this for the gut?
Thoracocolumbar
T1 - L2
T5 - L2
How do impulses from the sympathetic nervous system interact with the sympathetic chain?
They just pass through, they DONT synapse
What are the 3 nerves that form from sympathetic nerves coalecesing in the GI system?
Greater splanchnic nerve
Lesser splanchnic
Least splachnic
Following the 3 splanchnic nerves what happens to the impulse?
Synapses with prevertebral ganglia then the post ganglionic neurone synapses to tsupply thee organ
What are the 2 main plexuses of the Enteric Nervous System?
Submucosal/Meissners plexus
Myenteric (Auerbachs plexus)
What is the general action of the thoracolumbar outflow/sympathetic outflow on the GI system?
Reduces blood flow to viscera turning off digestion
Where is the Submucosal/Meissners plexus located?
In the submucosa
Where is the Myenteric/ Auerbachs plexus located?
Between the circular and longitudinal muscle layers
What is the role of the submucosal plexus?
Controls secretion and blood flow in gut
What is the role of the Myenteric/Auerbachs plexus?
Controls gut motility
So coordinates muscle contraction for peristalsis
