what is responsible for difficulty in localizing visceral pain?
receptor # and receptor field
-refer to somatic body structure
where do primary visceral afferent fibers synapse?
solitary nucleus in medulla
location of osmoreceptors and internal thermal receptors
parasympathetic nerve fibers**
carry info. originating from physiologic receptors (innocuous input)
sympathetic nerve fibers**
carry input from nociceptors
what makes up the anterolateral system?
spinoreticular fibers and spinothalamic fibers
which region of the brain do you perceive visceral pain?
insula and parietal operculum
what are the 2 ways visceral nociceptive stimuli can reach the cortex?
- direct - anterolateral system
2. indirect - ascending reticular formation system (involved in consciousness)
visceral afferent and somatic afferent fibers enter the same posterior root
-visceral afferent fibers have collaterals that synapse on somatosensory afferent fibers causing referred pain
sympathetic vs. parasympathetic levels
SNS - thoracolumbar (T1-L2/3)
PNS - craniosacral (S2-S4)
CN 9 and 10**
contain sensory ganglion (collection of cell bodies)
- both carotid sinus and carotid body afferent fibers carried to CNS via CN9 (glossopharyngeal)
- aortic baroreceptors and chemoreceptors afferent fibers carried to CNS by CN10 (vagus)
- fibers merge together when entering CNS at solitary nucleus (medulla)
what nerve is the info. from the carotid body and sinus carried by?
what nerve is the baroreceptor and chemoreceptor of aortic arch and body carried by?
projections from solitary nucleus**
- brainstem and hypothalamus
- dorsal vagal nucleus - preganglionic parasympathetic fibers; vagal trigone associated –> thoracic and abdominal viscera
- nucleus ambiguous - fibers to RALM (parasympathetic) –> larynx, pharynx, and esophagus muscles
- rostral anterolateral medulla (RALM) –> intermediolateral cell column (sympathetic fibers)
dorsal vagal nucleus and nucleus ambiguous
parasympathetic fibers that bring about a vasodepressor response (decrease HR, BP)
-decrease when dealing with orthostatic hypotension
rostral anterolateral medulla
sympathetic fibers that bring about a vasopressor response (increase HR, BP)
-decrease when dealing with HTN, increase with orthostatic hypotension
what occurs with lesion in thalamoperforating artery?
damage to ARAS in thalamus leading to coma
what are the 4 sympathetic ganglion?
celiac, aorticorenal, superior, and inferior mesenteric
what comprises a nerve plexus?
sympathetic ganglion and preganglionic parasympathetic nerve fibers
grey vs. white rami communicantes
white and grey - found from T1-L2
grey - found above T1 or below L2
superior cervical ganglion
largest paravertebral ganglion
-give rise to internal carotid and external carotid nerves
damage of superior cervical ganglion
-miosis, ptosis, flushing, anhidrosis
what is the ENS normally regulated by?
- PNS - enhancing
- SNS - inhibitory
brainstem structure coordinating autonomic functions - many connections with CAN
- dorsal vagal nucleus and nucleus ambiguous –> parasympathetic
- intermediolateral cell column and RALM –> sympathetic