chapter 7 Flashcards
(27 cards)
-motor
-pyramidal decussation (cervicomedullary junction)
lateral corticospinal tract
-sensory (vibration, joint position, fine touch)
-internal arcuate fibers (lower medulla)
posterior column medial lemniscal pathway
-sensory (pain, temp, crude touch)
-anterior commissure (spinal cord)
anterolateral pathway
somatosensory pathway refers to?
touch, pain, vibration, proprioception (understand joint and limb position)
superficial sensory information is considered?
touch, pain and temp
muscoskeletal sensory information refers to?
pain and proprioception (body static joint position)
-fast conduction
-first order neuron synapses with 2nd order neuron in dorsal horn, 2nd order neuron crosses midline (1-5 spinal segments) above or below. then axons extend contralaterally then make it way to VPL, axons third order neuron to sensory cortex
-sharp back pain trying to lift something
neospinothalmis
slower conduction and divergent (go in different directions)
-dural thrombing after sharp pain that follows
paleospinothalamic
____ and ___ are parrallel tracts through anterolateral pathway
neospinothalamic and paleospinothalamic
explain difference between A delta fiber and C fibers
- A delta fibers: info about cooling and fast
- C fibers info about heat, slower, sharp pain followed by dull pain
Lesion in the VPL causes?
interrupts the ability to localize the pain stimulus
explain DCML vs Neospinothalamic
- DCML: primary axons send ipsalaterally and crossing happens at medulla
- neospinothalamic: ascending axons are secondary axons and send contrallaterally and crossing happens in spinal cord
____travel from the trigeminal nerve down to the medulla then to the upper cervical cord before it synapses. 2nd order neuron crosses midline then to VPM. 3rd order neuron goes out to cortex.
fast pain from the face
explain fast pain vs slow pain
- fast: can localize, small mylinated a delta fibers carrying pain info, axons enter through dorsal lateral tract, terminate in lamina 1,2 or 5 of dorsal horn and this secretes glutamate. 2nd order neuron will be in lamina 1,2 or 5 then axon crosses midline at anterior commisioner then go up to the thalamus in the neospinothalamic tract. 3rd order neuron goes from VPL into the somatosensory cortex
- slow: can not localize, can not define exactly where you feel pain. first order neurons go to lamina 1,2 or 5 and release substance P. then interneurons synapse on ascending neurons in lamina 5 and 8, substance P modulate pain perception into ascending neurons. Ascending axons reach midbrain (reticular formation-sends thru brainstem, medulla, pons, midbrain and thalamus)
region around cerebral aquaduct
periaqueductal gray
-visual reflex
-makes us turn our eyes to pain
superior colliculus
-goes on to the reticular formation this increase enital arousal and attention. continuous stimulation drives the arousal to anger or sexual arousal
-general stimulation is arousal and awareness
spinoreticular tract
what makes up the posterior column
nucleus gracillis and nucleus cutaneus
what makes up the nucleus gracillis in the posterior column
leg and lower trunk
what makes up the nucleus cutaneus in medulla in the posterior column
upper trunk, arm, neck and occiput
where does the fasculus cuneatus originate?
above T6
where does the fasciculus gracilis originate?
below T6
-originate from posterior throacic nucleus of clarke (lamina 7)
-present in region T1-L2 (lower half)
-ipsalateral project to cerebellum and gets info from inferior cerebellum penuncle
dorsal spinocerebellar tract
-rostospinocerebellar tract and ventral work together to provide feedback to cerebellum about the descending motor tracts. do not provide any info on peripheral receptors
-enter cerebellum from superior penuncle
-get info from both sides of body specifically lower limb
ventral spinocerebellar tract
