Nerves Flashcards
What spinal levels do the sympathetic nerves innervating the gut arise from?
T5 - L3
Where do the sympathetic pre-ganglionic nerve fibres innervating the gut travel?
Travel through the sympathetic chain without synapsing
What do the sympathetic pre-ganglionic nerve fibres do after travelling through the sympathetic chain?
Bundle together to form larger nerve fibres
What larger nerve fibres do the sympathetic pre-ganglionic nerve fibres join together to form?
Greater splanchnic nerve
Lesser splanchnic nerve
Least splanchnic nerve
Which pre-sympathetic nerve fibres join together to form the greater splanchnic nerve?
T5 - T9
Which pre-sympathetic nerve fibres join together to form the lesser splanchnic nerve?
T10 - T11
Which pre-sympathetic nerve fibres join together to form the least splanchnic nerve?
T12 on its own!
Where does the greater splanchnic nerve travel to?
Travels to the coeliac ganglion
Where does the lesser splanchnic nerve travel to?
Travels to the superior mesentetic ganglion
Where does the least splanchnic nerve travel to?
Travels to the inferior mesenteric ganglion
Where do the greater, lesser and least splanchnic nerves synapse with sympathetic post-ganglionic nerve fibres?
At their corresponding ganglion
What do the post-ganglionic sympathetic nerve fibres from the coeliac ganglion innervate?
Foregut structures
mainly smooth muscle in blood vessels
What do the post-ganglionic sympathetic nerve fibres from the superior mesenteric ganglion innervate?
Midgut structures
mainly smooth muscle in blood vessels
What do post-ganglionic sympathetic nerve fibres from the inferior mesenteric ganglion innervate?
Hindgut structures
mainly smooth muscle in blood vessels
What runs with sympahetic nerve fibres between the spinal cord and the gut?
Visceral afferent nerve fibres
What information do visceral afferent nerve fibres carry?
Sensory information
- pain
- reflexes
What carries parasympathetic innervation to the gut?
Vagus nerve
Pelvic splanchnic nerves
What part of the gut does the vagus nerve innervate?
Foregut and midgut structures
What part of the gut do the parasympahetic pelvic splanchnic nerves innervate?
Hindgut
Where do the pelvic splanchnic nerves arise from?
They are parasympathetic pre-ganglionic nerve fibres
so they arise from the spinal cord
What spinal levels do the parasympathetic pre-ganglionic pelvic splanchnic nerves arise from?
S2 - S4
Where do the parasympathetic pre-ganglionic nerve fibres synapse with the post-ganglionic nerve fibres?
In the walls of the viscera
What parts of the hindgut do the parasympathetic post-ganglionic nerve fibres innervate?
Smooth muscle in walls of gut
Glands
Where are the right and left vagus nerves located in relation to the oesophagus and stomach?
Right vagus nerve is posterior
Left vagus nerve is anterior
What is the explanation for the location of the right anf left vagus nerves in relation to the stomach?
Foregut rotates 90degrees clockwise during development
