Flashcards in Somatosensory Pathways Deck (19)
Where is the C1 dermatome?
C1 does not have a dermatome
Thalamus to cortex: ipsilateral or contralateral?
What tract contains fibers for fine touch, vibration, and proprioceptive sensation?
medial lemniscal tract
What tract contains fibers for pain and temperature?
The spinothalamic tracts carries what kind of signals?
pain and temperature
Where do fibers carrying pain and temperature information synapse?
dorsal gray horn onto secondary afferent fibers
Where do secondary afferent spinothalamic fibers run?
from dorsal gray horn across white commissure to contralateral spinothalamic tract
Where are the spinothalamic tracts located?
anterolateral portion of cord cross section
Where do fibers of the spinothalamic tract terminate?
ventral posterior lateral thalamus
What are the two divisions of the medial lemniscus?
What fibers are carried in the fasciculus gracilis?
afferent from lower body
What fibers are carried in the fasciculus cuneatus?
afferent from upper body
Where do the second order neurons from the spinothalamic tract synapse?
postereoventral lateral (PVL) thalamus
Where do the third order neurons from the spinothalamic tract synapse?
PVL thalamus --> cortex
What is a somatotropic map?
spacial neuronal relative relationships are preserved throughout somatosensory system
What is convergence?
second order neurons receive synapses from 2+ first order afferent neurons --> second order neurons have larger receptive fields
Describe a cordotomy
palliative treatment, creating lesion on anterolateral funiculus (spinothalamic tract)
Describe a syringomyelia
cyst in center of cord, first causes loss of pain and temperature sensation in upper extremities