Download Neuro Objectives 19

Neuro Objectives 19

1.
Note: Clarke’s nucleus takes leg mechanoreceptors into the
spinocerebellar tract
Posterior horn: area where sensory afferents synapse
Intermediolateral horn: area of sympathetic pre-ganglionic cell bodies
(thoracolumbar outflow)
Anterior horn: area where motor efferents receive stimuli
Posterior funiculi: area where large fibers (touch/position) travel
Lateral funiculi: area where corticospinal tract and most of spinothalamic tract
travel
Anterior funiculi: area where some spinothalamic tract travels
Anterior white commisure: area where fibers cross the midline at each spinal
cord level
Lissauer’s tract: area where small myelinated/unmyelinated (pain/temperature)
fibers enter the spinal cord
Substantia gelatinosa: area where small myelinated/unmyelinated
(pain/temperature) fibers synapse before crossing the midline to join the
spinothalamic tract
Dorsal rootlet: area where sensory afferents enter the spinal cord
Ventral rootlet: area where motor efferents leave the spinal cord
2.
Big (lots of white matter)
C1 nerve
C1 vertebra
C2 nerve
C2 vertebra
C7 nerve
C7 vertebra
C8 nerve
T1 vertebra
T1 nerve
Conus medullaris (L1, L2)
Cauda equina
Dural sac (S2)
Small (not much white matter)
3.
Upper cervical: small anterior horns, large cross-sectional area, lots of white
matter, fasciculi gracilis and cuneatus (big)
Lower cervical: large anterior horns, large cross-sectional area, lots of white
matter, fasciculi gracilis and cuneatus (small)
Thoracic: intermediolateral cell column, medium cross-sectional area, medium
amount of white matter, fasciculus gracilis only
Lumbar/sacral: large anterior horns, small cross-sectional area, small amounts
of white matter, fasciculus gracilis only
4.
Locations of:
a.
Alpha motor neurons: anterior horn (big movements)
b.
Gamma motor neurons: anterior horn (sensitivity of movement)
c.
Preganglionic sympathetic neurons: thoracolumbar intermediolateral
column (sympathetic output)
5.
Terminations in the dorsal horn of:
a.
Small myelinated/unmyelinated: Lissauer’s tract → Substantia
gelatinosa → spinothalamic tract → thalamus (VPL)
b.
Large myelinated: Posterior funiculus → posterior column nuclei →
medial lemniscus → thalamus (VPL)
 Note: gracilis – long tracts (i.e. legs); cuneatus – short tracts (i.e. arms)
6.
Stretch reflex (one level):
Flexor reflex (multiple levels):
7.
Arterial blood supply:
 Note: The anterior spinal arteries join to form one, single anterior spinal
artery
8.
Touch/position:
Ipsilateral
9.
Contralateral
Pain/temperature:
Ipsilateral
Contralateral
Cortex
Cortex
Thalamus
Thalamus
Medial lemniscus
Spinothalamic tract
Posterior column nuclei
Substantia gelatinosa
Posterior funiculus
Lissauer’s tract
Dorsal root
Dorsal root
Afferent
Afferent
10.
Voluntary movement:
Ipsilateral
Contralateral
Cortex
Internal capsule
Cerebral peduncle
Basal pons
Pyramid
Decussation of the pyramids
Corticospinal tract
Lower motor neuron
Ventral root
Efferent
11.
Fasciculis gracilis: ipsilateral proprioception from lower extremities
Fasciculus cuneatus: ipsilateral proprioception from upper extremities
Spinothalamic tract: contralateral nociception
Corticospinal tract: contralateral upper motor neuron tract
12.
Upper motor neuron damage: ventral root/spinal nerve; weakness, areflexia,
muscle atrophy
Lower motor neuron damage: corticospinal tract; weakness, hyperreflexia,
increased tone