spinal nerves - number
31 pairs
spinal nerves - number and type
31 pais 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
spinal nerves - names
C1 - C7 exit above the corresponding vertebra
C8 spinal nerve exit below
C3 exits….(area)
L2 exits….(area)
C3: above the 3rd cervical vertebra
L2: below the 2nd lumbar vertebra
vertebra disc hernitation?
nucleus polposus (soft central disc) herniates through annulus fibrosus (outer ring)
vertebra disc hernitation - direction
usually posterolaterally
vertebra disc hernitation - area
MC at L4-L5 or L5-S1
in adults, spinal cords extent to …
lower border of L1-L2
subarachnoid space (spinal cord) extends to
lower border of S2
lumbar puncture is usually performed between
L3-L4
L4-L5
caudal equina level
L3-L5
goal of lumbar puncture
obtain sample of CSF without damaging spinal cord
spinal cord tracts?
- dorsal column
- lateral spinothalamic
- anterior spinothalamic
- lateral corticospinal tract
- anterior corticospinal tract
spinal cord ascending tracts
- dorsal column
- lateral spinothalamic
- anterior spinothalamic
spinal cord descending tracts
- lateral corticospinal tract
2. anterior corticospinal tract
spinal cord - dorsal column transfers
- pressure
- vibration
- fine touch
- propioception
spinal cord axon fibers in dorsal column are divided to (and location)
- fasciculus gracilis –> medial
2. fasciculus cuneatus –> lateral
spinal cord - dorsal column - fasciculus gracilis vs fasciculus cuneatus according function
- fasciculus gracilis –> lower body, legs
2. fasciculus cuneatus –> upper body, arms
spinal cord - dorsal column - distribution of spinal cord segments - medial to lateral
fasciculus gracilis: sacral lumbar to middle thoracic
fasciculus cuneatus: thoracic cervical to cervical
spinal cord - lateral spinothalamic tract transfers
pain
temperature
spinal cord - lateral corticospinal tract - distribution of spinal cord segments - medial to lateral
cervical to sacral
spinal cord - anterior spinothalamic tract transfers
crude touch (απροσδιόριστη) pressure
distribution of spinal cord segments - medial to lateral - lateral corticospinal tract vs dorsal column
lateral corticospinal tract –> cervical to sacral
dorsal column –> sacral to cervical
spinal cord descending tracts
- lateral corticospinal tract
2. anterior corticospinal tract
spinal cord - lateral corticospinal tract - function
voluntary motor
spinal cord - anterior corticospinal tract - function
voluntary motor
spinal cord - lateral corticospinal tract - distribution of spinal cord segments - medial to lateral
cervical - sacral
spinal cord - ascending tracts - correlation between cross and synapse
ascending tracts synapse and then cross
spinal cord - dorsal column transfers
- pressure
- vibration
- fine touch
- propioception
spinal cord - dorsal column direction
1st neuron: sensory ending –> cell body in dorsal root ganglion –> enter spinal cord, ascend ipsilaterally in dorsal column –> 1st synapse to ipsilateral nucleus cuneatus or gracilis (medulla) –>2nd neuron: decussates in medulla –> ascends contralaterally in medial lemniscus –> 2nd synpase on VPL of thalamus
–> 3rd neuron: sensory cortex
spinal cord - dorsal column - 1st neuron
sensory nerve endings
spinal cord - dorsal column - 1st neuron synapse to
ipsilateral nucleus cuneatus or gracilis (medulla)
spinal cord - dorsal column - 2nd neuron direction
decussates in medulla –> ascends contralaterally in medial lemniscus
spinal cord - dorsal column - synapse on thalamus - nulceus
Ventral posterolateral nucleus (VPL)
spinal cord - spinothalamic tract transfers
lateral: pain, temperature
anterior: crude touch, pressure
spinal cord - spinothalamic tract - direction
1st neuron: sensory nerve ending (Αδ and C fibers) –> cell body in dorsal root ganglion –> enters spinal cord –> synapse 1: ipsilateral gray matter (posterior horn) –> 2nd neuron: decussates at anterior white commissure –> ascends contralaterally –> synapse 2 on ventral posterolateral nucleus (VPL) of thalamus –> 3rs neron to sensory cortex
spinal cord - descending tracts? and function
- lateral corticospinal tract
- anterior corticospinal tract
VOLUNTARY MOTOR
spinal cord - lateral corticospinal tract - direction
upper motor neuron: cell body in 1ry motor cortex –> descends ipsilaterally, through internal capsule, most fibers decussate at caudal medulla (pyramidal decussation) –> descents contralaterally –> synapse at cell body of anterior horn –> lower motor neuron: leaves spinal cord and synapse (2) at NMJ
dorsal column synapses on thalamus - nucleus?
Ventral posterolateral nucleus (VPL)
spinoathalamic tract synapse on thalamus - nucleus?
Ventral posterolateral nucleus (VPL)
lateral corticospinal tract - decussation?
most fibers decussate at caudal medulla (pyramidal decussation)
dorsal column tract - decussation?
in medulla
motor neuron - weakness - UMN vs LMN lesion?
both
motor neuron - atrophy - UMN vs LMN lesion?
LMN
motor neuron - fasciculations - UMN vs LMN lesion?
LMN
motor neuron - reflexes - UMN vs LMN lesion?
increase in UMN lesion
decrease in LMN lesion
motor neuron - tone - UMN vs LMN lesion?
increase in UMN lesion
decrease in LMN lesion
motor neuron - Babinski - UMN vs LMN lesion?
UMN (+)
LMN (-)
motor neuron - spastic paralysis - UMN vs LMN lesion?
UMN
motor neuron - flaccid paralysis - UMN vs LMN lesion?
LMN
motor neuron - clasp knife spasticity - UMN vs LMN lesion?
UMN
fasciculations?
muscle twitching
postitive Babinski is normal in
infants
muscle tone?
muscle’s resistance to passive stretch during resting state
clasp knife spasticity
the resistance of an affected muscle is not the same throughout the range of movement, but tends to be most marked when passive movement is initiated and then diminishes as the movement continues (ΣΟΥΓΙΑΣ)
spasticity?
increase in tone
flaccidity
hypotonia
types of hypertonia
- spasticity
2. rigitity
rigitity?
consists of increased resistance to passive movement that is independent of the direction of the movement