Spinal Cord 3 Flashcards
When do you only get lower motor neuron symptoms?
what are lower motor neuron symptoms?
where you have lower motor neuron damage
fasciculations, paralysis, atrophy
Motor tracts originate where?
in the cortex and brainstem
what is the only tract that originates in the cortex?
costicospinal tract
all other UMN tracts except the corticospinal originate where?
these tracts are called?
in the brainstem (infratentorial)
extrapyramidal UMN tracts
What are the descending tracts?
corticospinal
extrapyramidal UMN tracts
what are the extrapyramidal UMN tracts?
- Reticulospinal
- Tectospinal
- Rubrospinal
- Vestibulospinal
- Olivospinal
What does the Reticulospinal tract do?
voluntary and reflex movements via modulation of motor neurons in anterior horn.
(there are two reticulospinal, lateral and medial)
What does the Tectospinal tract do?
Reflex postural movements in respinse to visual stimuli
(like when there is a flash of light and you look at where it came from)
What does the Rubrospinal tract do?
inhibits extensors muscles,
stimualtes flexor muscles
what is the olivospinal do?
involved in movement of muscles
what is the Vestibulospinal?
- stimulates extensors
- inhibits flexors
- involved in postural control and balance
(there are two vestibulospinal, lateral and medial, see vestibulospinal slide).
where does the lateral corticospinal descend through?
What about the anterior corticospinal?
Lateral: descends through brain ipsilaterally, then crosses and descends contralaterally in cord.
Anterior: descends ipsilaterally all the way to the cord, then innervates bilaterally.
what does the corticospinal tract do?
Voluntary, discrete (FINE!), skilled motor movements.
(gives you the ability to make movements voluntarily specific)
(There are two corticospinal, lateral and anterior, see later).
where does the corticospinal tract come from?
Where does the corticospinal tract descend through?
is derived from precentral gyrus, postcentral gyrus, and premotor cortex.
descends through the posterior limb of the internal
capsule.
What will the Lateral Corticospinal Tract activate?
the contralateral distal musculature.
The corticospinal tract is actually composed of axons
from what parts of the brain?
precentral, postcentral, and premotor cortex
what are the Corticospinal Tract lesion symptoms?
- Paresis (hemiparesis)
- Babinski sign ‘present’
- Hoffman’s sign present: you flick 1 finger, the others close to it also flinch (not normal)
- Abdominal reflex absent
- Cremasteric reflex absent
- Spasticity, which is hyper-
- Reflexia of DTR’s, clonus, and
- Increased muscle tone (rigidity)
A stroke/lesion above the brainstem only affects which tract?
corticospinal tract
when there is damage to the corticospinal tract in the spinal cord, the symptoms are on which side?
ipsilateral
The extrapyramidal tracts take care of what?
gross voluntary body movement
The reticulospinal tract has 2 parts, what are they?
how does each descend and what is its target?
Medial (pontine): it descends ipsilateral and innervates the extensors
Lateral (medullary): it descends ipsilateral and innervates the flexors
when do you use the Bing test and what is it?
bing test is another way of testing babinski sign by tapping on top of the foot in ppl who have big calluses on the foot