Unit 3: Pain and Pathways Flashcards
Fast pain
Spinothalamic, initial and immediate sharp sensation
Slow pain
Spinolimbic, dull throbbing ache following fast pain that is not well localized
Fast pain pathway
neurons bring info to dorsal horn, cross midline go to thalamus, thalamus to cerebral cortex via VPL
Facial pain pathway
fast pain travels to trigeminal, to pons down to spinal nucleus, crosses and ascends trigeminal lemniscus to thalamus, to cortex
Arrangement of facial pain pathway can lead to?
crossed analgesia
Lesion cerebrum, midbrain and pons causes
Contralateral paralysis
Medial pain system
divergent ascending network of neurons, uses several pathways, not like fast pain
Activity of medial pain system elicits?
affective, motivational, witdrawal, arousal, and autonomic responses
Spinolimbic tract perceives
Pain
Which tracts are involved with arousal, motivation, reflexes, control of sensory?
Spinoreticular, spinomesecephalic
Spinomesencephalic tract
Involved with visual auditory reflex, carries pain info to superior colliculus and periaqueductal gray matter
Periaqueducatl gray matter is part of?
Descending pain control system
Periaqueducatl gray matter is part of?
Descending pain control system
Spinoreticular tract
synapse in reticular formation, modulates attention, arousal, can disturb sleep cycle
Spinolimbic tract
Transmit slow pain info, emotional response to pain and reflexive movement
Cerebellar pathways
Posterior spinocerebellar, and cuneocerebellar
Cuneocerebellar pathway
Transmits info from upper r half of body and arms, 2nd synapse with lateral cuneate nucleus, entirely ipsilateral ascending
Posterior spinocerebellar pathway
Transmits info from lower half of body and legs, 2nd synapses with nucleus dorsalis, entirelly ipsilateral
Basal ganglia
receives input from motor and sensory parts of brain to aid in control of movement
Motor loop of basal ganglia
excites putamen, inhibits globus pallidus, thus activating thalamus, intiates movement commands, stopping cortical activation inhibits thalamus again
Globulus pallidus
always actively inhibiting the thalamus
Parkinson’s
Substantia nigra degenerates reducing inhibition of GP, VL nucleus in thalamus cannot depolarize as readily
Hungtington’s
Loss of inhibitory neurons results in VL firing without restraint
Cerebellum function
Maintain posture, coordinate contraction sequence, provides error correction in slow movement
Vermis contributes to
ventromedial pathways
Pontine nuclei
axons from layer V pyramidal cells in the sensorimotor cortex form massive projections to pons
Corticopontocerebellar projections
20 times larger than puramidal tract, pons supplies input to CB outputs flow through the deep nuclei and to thalamus, thalamic projections terminate on primary motor cortex to coordinate movement
Corticopontocerebellar projections
20 times larger than puramidal tract, pons supplies input to CB outputs flow through the deep nuclei and to thalamus, thalamic projections terminate on primary motor cortex to coordinate movement
Pyramindal tract
Direct order to make a muscle move, 2 motor neurons
Corticospinal tract
voluntary control of torso including limbs, sequence of two motor neurons, crossover at the brain stem
Corticobulbar tract
motor control of head via cranial nerves, crossover and stay in brainstem at cranial nerve nuclei
Internal capsule
Large confluence of the descending axons
Ventromedial pathway
indirect cortical control-proximal musculature, uses sense info about balance, vision, body position; can activate LMN
Lateral pathways
Direct cortical control-distal musculature
Vestibulospinal tract
posture and balance
Tectospinal tract
Orienting response
Pontine
Enhances antigravity reflexes
Medullary
Liberates antigravity muscles from reflex during voluntary movements
Motor cortex
Intitiates voluntary movement instruction along laeral paths
