27 JUNE 2019 Flashcards
mostly all chapter 13? no theres a lot of chapter 14
list five types of involuntary muscle movements:
- muscle cramps
- tremors
- fasciculations
- myoclonus
- fibrillations
what are fasciculations:
spontaneous oscillations of muscle fibers
a fasciculations can be two things:
benign or pathologic
when is there a benign fasciculation?
when there is no cormorbidity w/ s/s of damage
when is there a pathologic fasciculation?
when there is cormorbidity w/ s/s of damage
what is myoclonus?
the whole boyd ocntracts doesn’t know what caues it
- what happens when you’re on the verge of falling asleep
what are tremors?
involvuntary muscle contractions:
what are the two types of tremors?
resting
action
resting tremors are: def + ie:
oscillating back and forth type movement of a limb
ie: parkinson’s dx
action termors that we are concerned about are
name + def + ie:
intention
its a tremor whenever you move
ie: cerebellar dysfx
fibrillations are
always pathologic
spontaneous depolarization of a 1 muscle fiber
how do you detect fibrillations?
w/ a needle = end of need goes into your fiber and will feel a tiny electrode that make it vibrate
= NEEDLE EMG
name the five potential sources of damage to nerves:
- trauma
- blunt / sharp - infection
- neurogedenerative
- vascular dx
- tumors
what are the two types of trauma:
blunt: compression of proximal end of nerve (squish it) s
sharp: cut peripheral motor neuron
infection def and ie:
infections attack cell bodies ie: polio
neurodegenerative ie;
ALS
vascular dx def:
nerves need rich supply of oxygen so this happens when they do not get enough blood
tumors:
bunt trauma
grow and press on nerve then leak gluatamate = excitotoxictiy
name three signs of LMN lesions:
- denervation
- decrease or loss of reflex
- paresis or paralysis
difference between sp nerve and peripheral nerve damage:
spinal nerve = weakness (paresis)
peripheral nerve = paralysis / no sensory info
when there is a loss of reflex that means:
the spinal level N is cut = decrease b/c stretch going into the spinal cord can’t come back and form a response
denervation means:
wallerian denervation: where the distal axon dies and the muscle fiber loses its axon
where can LMN lesions happen?
ventral root
peripheral root
spinal nerve
***all look differently depending
what neuron does LMN lesions affect?
a-alpha
name the two types of atrophy:
disuse
denervation
disuse atrophy def:
muscle gets smaller than normal still has bulk though
denervation atrophy def:
muscle will wither away from nothing
“flaccid paralysis” def:
- loss of muscle tone
- inability to contract
- due to injury of alpha motor neuron
hypotonia def:
losses some of alpha motor neurons
flaccidity def:
it if losses all muscle tone
completely resistive to passive stretch
where does motor planning take place?
the basal ganglia
what two places does UMN start?
the cerebral cortex and brainstem
where does the cerebral cortex send messages to ?
the LMN (and the brainstem)
where does the brainstem send messages to ?
the spinal cord
the cerebral cortex is made of what and called what?
grey UMN hemisphere
cortical origin
the brainstem is called
subcortical orgin
what has greater voluntary control?
the cerebral cortex
what does the cortex control do?
DIRECTLY controls LMN and then muscles
what doe the brain stem do?
provides direction for the muscle (from info from the cortex)
sends messages that go down to the spinal cord
the medial group controls the
proximal muscles
sub cortical origin:
supports voluntary movements
guided by medially lateral cortical pathway
cortical origin:
has direct voluntary control of movement
the lateral group controls the
distal muscles
where does the reticulospinal (medial group) start
starts in the brainstem in the reticular formation
where does the reticulospinal project:
broadly out to the upper and lower extremities
what does the reticulospinal produce?
gross limb movement
lower degree of direct voluntary control
of postuarl muscles
the medial vestibulospinal projects to
the core axial
- upper bakc/ postural Mm
- head and neck
what does the medial vesibulospinal do?
maintains upright against gravity
lower degree of direct voluntary control
the lateral vestibulospinal
overall still controls core/proximal Mm
- axial & LE mm
lower degree of direct voluntary control
the lateral vestibulospinal is mostly:
unilateral
the three medial groups according to what they do:
- reiculospinal - picks stuff up against gravity
- medial vestibulospinal - upright against pull of gravity
- lateral vesitbulopsinal - keeps you upright against gravity
the fourth medial group is
medial corticospinal
medial corticospinal projects to
projects to the medial motor neuron pools bilaterally
medial corticospinal controls
neck shoulder trunk Mm
why is the medial cortico-spinal group different
it has direct control of the voluntary movement: because it comes from the cerebral cortex
what are the lateral group pathways?
- rubrospinal
2. lateral corticospinal
rubrospinal:
minor control of distal extensor extermity of UE
lateral corticospinal:
directly activates distal Mm
provides “fractinated” movement:
what does fractinated mean
any Mm in any combination I want = full voluntary control
lateral corticospinal does two things?
- direct control of LMN
2. guiding control to brainstem group
which pathway is the MOST IMPORTANT PATHWAY FOR VOLUNTARY MOVEMENT?
the lateral corticospinal
where is home for all the lateral corticospinal cell bodies?
home of the pre-central gyrus
what are the percentages of the medulla?
90% cross
10% stay
