CNS Classes 7 & 8 Flashcards
a ______ _____; is a set of neurons involved in enacting the reflex response in the basic spinal cord type
reflex arc
T/F there are 3 neurons involved in a reflex arc
true
_______; a first order neuron, communicating about nociception, temperature, stretch etc
afferent
the purpose of a ______ reflex is to protect the muscle belly from an overstretch injury
stretch
a stretch reflex arc begins with a _____ ________ neuron going directly to an alpha motor neuron and is monosynaptic
1A Sensory
during a stretch reflex, 1A ________ firing as the muscle belly elongates, especially if the stretch happens quickly or is nearing the end range
increases
as the muscle firing escalates, it increases ______ chemistry in the synapse, causing alpha activation the muscle tightens to counteract the stretch
excitation
1A neurons release __________
acetylcholine
the purpose of a ______ reflex is to protect the tendon from overstretch injury
GTO
GTO reflexes synapse in the _____ horn
dorsal
GTO reflexes use _____ sensory neurons
1B
1B is ________ but the reflex response needs to reduce stress on the tendon, requiring inhibition of alpha motor neurons
excitatory
T/F 1B decreases firing as the tendon elongates especially if the stretch happens quickly
false, 1B increases firing etc
1B releases ________ towards the interneuron which activates the interneuron; the interneuron releases ______ which is inhibitory alpha motor neurons
acetylcholine, GABA
in relation to reciprocal inhibition, 1A transmits back through the _______ horn and synapses with _______ motor neurons in the anterior horn
dorsal, alpha
when the quad 1A is activated by stretch, in addition to initiating a quad stretch reflex response it also activates a _______ ______
relaxation response
in relation to the GTO reflex. 1A transmits from the ______ and 1B from the _____, into the spinal cord through the dorsal horn
muscle belly, tendon
T/F each reflex arc can create a protective response
true
T/F HMC’s have no influence on the basic protective reflexes
false
______ is muscle hypertonia as a result of exaggerated dysregulated reflex response
spasticity
T/F spasticity does not occur as a result of damage to one HMC
true
spasticity typically results from ______ _____ lesions
white matter
______ ______, an infarction causes fatal axonal injuries to a group of neurons supplied by the affected artery
stroke pattern
______ ______; accumulation of a large number of plaques throughout the UMN’s even though they are small, they add up to disconnecting transmission from reaching the anterior horn cells in an effective way
MS pattern
traumatic _______ injuries can occur in numerous presentations - in the brainstem or in the spinal cord
traumatic brain injuries
T/F reflexes are autonomous - they do not require CNS involvement to perform their basic response
true
______ is velocity dependent, meaning it is more noticeable with fast movements/ stronger involuntary contractions due to rapid movement triggers
spasticity
T/F rigidity will have the same resistance in all directions affecting all muscles surrounding a particular joint equally
true
more tone in the initial parts of the movement is aka _____ _____ spasticity
clasp knife spasticity
T/F spasticity is usually accompanied by increased tendon reflexes and a Babinski response
true
with _____ muscle tone is increased even at rest and usually present during PROM
rigidity
_______; the primacy of the basic excitatory protective reflexes which are operating with poor or absent HMC modulation, exaggerated response to both normal and noxious stimuli
hyperreflexia
_____ cascade reaction: one stimulus results in the activation of a sequence of reflex responses that spread in either or both directions from the original activation
reflex
_____ dominance; the spasticity causing lesion causes the motor system to revert where flexion is the normal comfortable resting positions for the affected joints
flexion
______ sign; normal reflex in young infants and part of the basic full-body withdrawal reflex pattern
babinski’s
T/F the term Babinski’s sign is used when Babinski’s reflex is present abnormally
true
_______ alternating activation of agonist and antagonist stretch reflex responses acting on a joint causing reverberation
clonus
______ co- contractions: abnormal antagonist contractions that occur during voluntary agonist effort when observing it clinically it looks like rigidity
spastic
in muscle tone abnormalities, resting tone may be too _____ or too ______/ can fluctuate
high or low
T/F tone can drastically change with emotion, pain etc
true
patients with spasticity may have _____ motor control
diminished
patients with spasticity may have reduced _____, early activation of protective reflexes and _____
ROM, ischemia
1A neuronal _______; phenomenon in which 1a neurons add axon terminal branches increasing their number of synapses on their partner alpha motor neuron in the stretch reflex
sprouting
T/F neuronal sprouting intensifies spasticity because it is hyperreflexic
true
reduced spinal cord availability of _____; reduces the strength and reaction of the GTO reflex because the GTO response while still present is weaker and shorter in duration
GABA
______ increases spasticity due to lack of circulation
ischemia
T/F compensatory postures and movements may also overstress muscles and result in spastic reactions
true
______ compromises tissue circulation and joint health, therefore increasing spasticity by reducing the amount of tolerable movement
contracture
