B7-021 Spinal Cord Injury Flashcards
responsible for bladder/bowel retention
SNS
responsible for bladder/bowel emptying
PNS
what is the effect of SNS on the bladder walls and sphincter?
relaxation of bladder walls
constriction of sphincter
what is the effect of PNS the bladder walls and sphincter?
contraction of bladder walls
relaxation of sphincter
where do the PNS preganglionic neurons that control bowel/bladder function reside?
sacral cord (S2-S4)
where do the SNS preganglionic neurons that control bowel/bladder function reside?
thoracic and upper lumbar cord
sensory afferents to the bowel and bladder enter at the […] cord
sacral
controls the detrusor muscles in the bladder
frontal micturition inhibiting area
(in cortex)
controls the activity of sphincters
sensorimotor sphincter control area
(in cortex)
region in the pons that organizes functional activity of the bowel/bladder
pontine micturition center
allows changes to bowel/bladder function under voluntary control from the cortex
pontine micturition center
the parasympathetic preganglionic neurons that control emptying the bladder are located in the […] cord
sacral
the sympathetic preganglionic neurons that control bladder retention are located in the […] cord
lower thoracic/upper lumbar
smooth muscle bladder structures under the control of the autonomic nervous system [2]
detrusor muscle
internal sphincter
the external sphincter is under […] muscle control
voluntary
in order for the parasympathetic nervous system to allow for bladder emptying, the detrusor must [….] and the internal sphincter must […]
detrusor must contract
internal sphincter must relax
in order for the sympathetic nervous system to allow for retention, the detrusor must [….] and the internal sphincter must […]
detrusor must relax
internal sphincter must contract
send information about the state/stretch of the bladder to higher centers
sensory neurons
the origin of the sympathetic innervation to the bladder
IMLC synapses at inferior mesenteric ganglion
the origin of the parasympathetic innervation to the bladder
pons –> sacral cord
innervates the external sphincter
pudendal nerve
the origin of voluntary motor innervation to the bladder
pons –> ventral horn of sacral cord –> pudendal nerve —> external sphincter
a reflex loop in the spinal cord allows for [….] of the bladder
reflex emptying
(like in a baby, before these pathways are well developed)
lesions between the pons and sacral cord will cause symptoms similar to
UMN lesions
flaccid, acontractile bladder
overflow incontinence due to laughing, sneezing, coughing, etc
acute central lesion or peripheral lesion
(catheterization can help prevent overflow)
hyperreflexic bladder
low urine volume
chronic central lesions
carries touch, vibration, and sensory information from the skin to the primary somatosensory cortex
DC/ML
carries voluntary motor signals from the motor cortex to the peripheral neurons
corticospinal tract
carries pain and temperature information from the skin to the primary somatosensory cortex
spinothalamic tract
things to consider when localizing lesions [4]
- what side of the body is affected?
- what region (level) of the body is affected?
- what sensory is affected?
- what motor is affected?
lesions in the spinal cord of the spinothalamic pathway will produce […] deficits
contralateral
lesions in the spinal cord of the corticospinal and DC/ML pathways will produce […] deficits
ipsilateral
spastic paralysis
hyperactive reflexes
little atrophy
indicates damage in
UMN
flaccid paralysis
hypoactive reflexes
atrophy
indicates damage in
LMN
constellation of symptoms ocurring after spinal cord hemisection is called [….]
Brown-Sequard syndrome
(can be transection or caused by tumor)
hemisection of the corticospinal tract will cause
ipsilateral spastic paralysis that begins at the level of transection and affects every level below that
hemisection of the DC/ML tract will cause
ipsilateral deficit of touch, proprioception, and sensation
that begins at the level of transection and affects every level below that
hemisection of the spinothalamic tract will cause
contralateral deficit of pain and temperature sensation
that begins a couple levels below transection and affects every level below that
damage to the ventral horn of the spinal cord will damage what pathway?
damage the alpha motor neurons (LMN) for the corticospinal pathway
(would see ipsilateral flaccid paralysis following a myotome)
gray matter
damage to the dorsal horn of the spinal cord will damage what pathway?
damage to both DC/ML and spinothalamic pathways
(dermatomal ipsilateral loss of both touch and pain/temperature information)
gray matter
damage to the fasciulus gracillis would result in
ipsilateral loss of touch and vibration sensation in the legs
white matter damage to the cord would result in […] pain and temperature loss
contralateral
damage to the […] produces deficits confined to a dermatomal level
gray matter
damage to the […] impedes information that is ascending/descending the cord and results in deficits at the level of damage and below
white matter
carry somatosensory information about ipsilateral touch and proprioception
dorsal columns
carries the axons of UMNs
corticospinal tract
(damage to the white matter will always result in spastic paralysis)
the first order neuron of the spinothalamic tract lies in the
dorsal root ganglion
the cell bodies that give rise to the axons in the spinothalamic tract reside in the
contralateral dorsal horn of the spinal cord
the cell bodes that give rise to the lateral corticospinal tract are located in the
contralateral motor cortex
the cell body of the UMN lives in the
contralateral motor cortex
damage to the DC/ML will result in […] deficit
ipsilateral
damage to the spinothalamic tract will result in […] deficit
contralateral
why is the sensory deficit level for pain and temperature loss lower than the affected level?
sensory neurons initially ascend ipsilaterally for a couple of levels, then dessucate and ascend contralaterally
how would a mid-thoracic lesion affect bladder function?
loss of UMN pathway of voluntary control
SNS and PSNS still intact, but loss of voluntary control would cause a hyperreflexic, spastic bladder with urge frequency and incontinence
pain and temperature afferents ascend […] for one to two levels (in Lissauers tract), then synapse in the […] dorsal horn (substantia gelantinosa)
ipsilateral
ipsilateral
(then second order neuron dessucates and ascends in contralateral ALS)
damage to the […] would produce ipsilateral flaccid paralysis in a dermatomal pattern
anterior horn
the spinothalamic tract dessucated in the […]
anterior white commissure
syrinx can cause
central cord syndrome
damage to […] results in hyperreflexive spastic bladder
axons descending from pons micturition centers
overflow incontinence results from damage to […] in the sacral cord
parasympathetic preganglionic neurons
