BRS Spinal Cord Flashcards
the spinal cord extends to the level of L___ in newborns but will be at the level of L____ inadults
L3 in newborns
L1 in adults
what are the borders of the spinomedullary junctions
foramen magnum
pyramidal decussation
emergence of first cervical nerve rootlets
the first cervical nerve and the coccygeal nerve are unique in that
they contain no dorsal root (no sensory)
meningeal ramus of the SC innervates
meninges and vertebral column
the gray communicating rami contains what type of fibers
unmyelinated postganglionic sympathetic fibrers
the ventral median fissure underlies what artery?
anterior spinal a
lamina 1 is associated with what innevation
light touch
pain
temp
what is lamina 2 known as
substantia gelatinosa
homologous to spinal trigeminal nucleus
light touch, pain, temp
myotatic reflex
monosynaptic
afferent - muscle spindle and DRG of its 1a fiber
efferent - ventral horn motor neuron
ascending pathways include
posterior column-medial lemniscus pathway anterolateral system lateral spinothalamic tract dorsal spinocerebellar tract ventral spinocerebellar tract cuneocerebellar tract
the posterior column-medial lemniscus pathway conveys what information to the thalamus
tactile discrimination, vibration, proprioception
the PCML pathway receives input from what type of receptors
pacini meissner corpuscles joint recpetors muscle spindles golgi tendon organs
the cell bodies for the first order neurons of the PCML pathway can be found where
dorsal root ganglia at all levels
the first order neurons of the PCML pathway give rise to the fasciculus gracilis, originating from the _____ extremity and the fasciculus cuneatus, arising from the ______ extremity
gracilis = lower extremity cuneatus = upper extremity
the cell bodies of the second order neurons in the PCML pathway are located within
the gracilis or cuneatus nuclei in the medulla
after synapsing in the nuclei in the medulla, the PCML pathway continues on the _____ ______ fibers before decussating to form the _______ lemniscus
gracile and cuneate nuclei –> internal arcuate fibers –> decussate –> medial lemniscus
the medial lemniscus carries proprioceptive input to the contralateral brainstem, terminating in the ____ of the thalamus
ventral posteriolateral nuclei
third order neurons in the PCML pathway transverse the ______ _______ of the internal capsule to project to the somatosensory cortex
posterior limb of the internal capsule
where do PCML fibers decussate
2nd order neurons from the gracile and cuneate nuclei cross the midline in the medulla
the anterolateral system carries what kind of information
light touch from free nerve endings and merkel tactile discs
the anterolateral system makes up what two tracts
ventral and lateral spinothalamic systems
the spinothalamic system crosses the midline at the _____ ______ commissure to ascend to the contralateral ventral funiculus
anterior white commissure
third order neurons of the spinothalamic system are found where in the thalamus
VPL nucleus of hte thalamus
the lateral spinothalamic tract carries what type of sensory information
pain, itch, temperature
what kind of receptors does the spinothalamic tract utilize
free nerve endings and thermal recpetors
what type of fibers does the lateral spinothalamic tract utilize
alpha-gamma nad C fibers (fast and slow)
first order neurons of the spinothalamic tract ascend in what tract
dorsolateral tract of lissauer –> ascend/descend 1-2 levels and synapse
second order neuron cell bodies in the lateral spinothalamic tract are found where
in the dorsal horn
they go on to decussate in the anterior white commissure and ascend
