viscerosensory Flashcards
viscerosensory definition
send signals about organ function to brain
spinal vs cranial
viscerosensory
cranial: functions of organs - drive ANS (vagus nerve)
spinal: what we perceive (dorsal horn)
where does viscerosensory information combine?
for spinal afferents
dorsal root ganglia
why is visceral pain generalised?
tissue innervation is sparse
we know this from dying the dorsal root ganglia
spinal afferent physiology
visceral non-painful sensations, visceral discomfort & pain, referred pain, local organ feedback, shaping emotional state
termination of spinal vs cranial afferents?
spinal - dorsal horn
cranial - NTS
how does info about nutrients in GI tract get sent to brain?
nutrients -> afferents -> vagus nerve -> nodose ganglia -> brain
stretch in stomach detected by mechanoreceptors
cranial afferent physiology
visceral non-painful sensations (e.g. feeling full), shaping emotional state, interoception (internal state of body), organ regulation, organ reflexes, neuroendocrine regulation
cell bodies for cranial afferents
nodose - inferior of vagus nerve
jugular - superior of vagus
petrosal ganglion
baroreflex
force blood in -> distension (detected by AAR & CSR) -> sent to brain (via. CSN & VN)
what happens when CSN and VN cut off?
wide range of b.p. = not maintained
describe phasic response of baroreceptor reflex
at peak systole, there is extra activation of aortic depressor nerve = increased firing
myelinated vs unmyelinated baroreceptor
mye: high fidelity, high sensitivity, more freq firing, a fibres, resting bp
unmye: low fidelity, low sensitivity, less frequent firing, c fibres, elevated bp
cranial viscerosensory pathway
periphery (cardiovascular, respiratory, hepatic, GI) -> vagus nerve -> 10th cranial nerve (& 9th and 7th) -> solitary tract -> NTS
visceral signals to ST-NTS synapse, release what NT?
result in glutamate release
