Psl300 - Motor, Ans & Muscle Questions And Correct Answers

PSL300 - MOTOR, ANS & MUSCLE
QUESTIONS AND CORRECT ANSWERS
SimpleA2reflexesA2-A2Ans--
SensoryA2neuronsA2makeA2synapsesA2withA2spinalA2cordA2motoneuronsA2toA2mediateA2si
mpleA2reflexes.A2ThisA2isA2theA2simplestA2formA2ofA2motorA2control

CentralA2PatternA2GeneratorsA2(CPGs)A2-A2Ans--
NetworksA2ofA2interneuronsA2inA2theA2spinalA2cordA2andA2brainstemA2coordinateA2theA2inte
ractionA2ofA2manyA2differentA2motorA2groupsA2(locomotion,A2respiration)

Complex/VolitionalA2MovementA2-A2Ans--
MotorA2outputA2thatA2isA2plannedA2andA2refinedA2byA2theA2motorA2cortex,A2basalA2gangliaA2
andA2cerebellum

MonosynapticA2reflexA2-A2Ans---
A2HasA2aA2singleA2synapseA2betweenA2theA2afferentA2andA2efferentA2neurons
-
A2StimulusA2toA2receptorA2toA2sensoryA2neuronA2toA2CNSA2toA2efferentA2neuronA2toA2target
A2cellA2toA2response


PolysynapticA2reflexesA2-A2Ans---
A2HaveA2twoA2orA2moreA2synapses.A2ThisA2somaticA2motorA2reflexA2hasA2bothA2synapsesA2
inA2theA2CNS.
-
A2StimulusA2toA2receptorA2toA2sensoryA2neuronA2toA2interneuronA2inA2CNSA2toA2efferentA2n
euronA2toA2targetA2cellA2toA2response

StretchA2ReflexA2-A2Ans---A2YouA2stretchA2it,A2itA2willA2contract"
-A2operatesA2atA2subconsciousA2level
-
A2stimulus:A2passiveA2stretchA2ofA2aA2muscleA2byA2appliedA2loadA2orA2contractionA2ofA2anta
gonistA2muscle
-A2response:A2activeA2contractionA2ofA2muscle;A2e.g.A2patellarA2tendonA2reflex
-
A2veryA2sensitiveA2andA2fastA2dueA2toA2muscleA2spindleA2afferents,A2andA2monosynapticA2c
onnectionA2toA2motoneurons

StretchA2ReflexA2PropertiesA2-A2Ans---A2essentialA2forA2stabilizingA2posture
-A2reflexA2strongestA2inA2posturalA2muscles
-A2latenciesA2ofA2aboutA225msA2forA2forearmA2muscles,A237msA2forA2ankleA2extensors
-
A2parallelA2multisynapticA2pathsA2throughA2spinalA2cordA2(branchesA2upA2toA2somatosenso
ryA2cortexA2asA2well)

,-
A2stretchA2reflexA2andA2allA2otherA2reflexesA2areA2designedA2forA2aA2specificA2functionA2(e.g
.A2stabilizingA2aA2joint)
-A2duringA2movement,A2reflexA2suppressed

GolgiA2TendonA2ReflexA2-A2Ans---A2"YouA2contractA2it,A2itA2willA2relax"
-
A2GTOA2(GolgiA2tendonA2organ)A2afferentsA2synapseA2onA2interneuronsA2inA2intermediateA
2zoneA2ofA2spinalA2cord
-A2interneuronsA2inhibitA2motoneuronsA2ofA2sameA2muscle
-A2stimulus:A2activeA2tensionA2inA2muscle
-A2response:A2relaxationA2orA2reductionA2ofA2tension
-A2itA2regulatesA2theA2levelA2ofA2activityA2byA2inhibitionA2-
A2complementaryA2toA2stretchA2reflex
-A2overA2exertionA2ofA2theA2muscleA2=>A2activatesA2GTOA2=>A2activatesA2interneurons
-
A2interneuronsA2=>A2inhibitA2motoneuronsA2(reduceA2contraction):A2toA2regulateA2theA2amo
untA2ofA2force
-A2excessiveA2loadA2=>A2muscleA2relaxesA2=>A2loadA2isA2droppedA2butA2muscleA2isA2saved

GolgiA2TendonA2ReflexA2PropertiesA2-A2Ans---A2PreventsA2movement
-A2ActsA2inA2concertA2withA2stretchA2reflexA2toA2stabilizeA2posture
-A2SuppressedA2whenA2netA2motionA2isA2desired

StretchA2andA2GolgiA2TendonA2ReflexesA2-A2Ans---
A2ifA2thereA2isA2overactivationA2ofA2biceps
-A2GTRA2willA2reduceA2activityA2inA2biceps

-A2ifA2thereA2isA2overactivationA2ofA2biceps
-A2tricepsA2(antagonisticA2muscle)A2stretches
-A2stretchA2reflex
-A2contractionA2ofA2triceps

FlexionA2WithdrawalA2ReflexA2-A2Ans---A2"YouA2touchA2hotA2stove,A2flexA2yourA2arm"
-A2stimulus:A2noxiousA2injuryA2ofA2limb
-A2response:A2flexionA2ofA2jointsA2proximalA2toA2stimulusA2(extensionA2distalA2toA2stimulus)
-A2nociceptorA2afferentsA2synapseA2onA2interneuronsA2inA2superficialA2dorsalA2hornA2-
A2slowlyA2conductionA2afferents
-A2multi-synapticA2pathA2toA2motoneurons
-
A2activateA2painA2receptorsA2inA2forearmA2=>A2flexionA2ofA2theA2proximalA2jointA2andA2exte
nsionA2ofA2theA2distalA2joint

ReciprocalA2inhibitionA2-A2Ans---
A2activationA2ofA2oneA2motorA2nucleusA2isA2coupledA2toA2inhibitoinA2ofA2antagonisticA2moto
rA2nucleus

, -A2e.g.A2activationA2ofA2flexorA2motoneuronsA2elicitsA2inhibitionA2ofA2antagonistA2extensors
-A2whenA2co-
contractionA2ofA2antagonistsA2desiredA2(forA2jointA2stiffness)A2thisA2circuitA2isA2suppressed

PatellarA2tendonA2reflexA2-A2Ans---A2"YouA2bangA2yourA2knee,A2youA2kick"
-A2tapA2onA2patellarA2tendonA2=>A2stretchA2quadsA2=>A2contractionA2ofA2quads
-A2simultaneouslyA2inhibitA2hamstringsA2contraction

CrossA2ExtensionA2ReflexA2-A2Ans---
A2"YouA2stepA2onA2somethingA2sharp,A2flexA2yourA2legA2whereA2thereA2isA2painA2andA2exte
ndA2theA2otherA2leg"
-
A2fullA2expressionA2ofA2theA2flexionA2withdrawalA2reflexA2involvesA2contralateralA2extension
A2forA2increasedA2posturalA2supportA2=>A2mainlyA2seenA2inA2legs
-A2commissuralA2interneuronsA2carryA2signalA2toA2contralateralA2spinalA2cord

ExtensorA2ThrustA2ReflexA2-A2Ans---
A2stimulus:A2pressureA2onA2soleA2ofA2footA2(innocuous)
-A2response:A2activationA2ofA2legA2extensors
-
A2mechanoreceptorsA2projectA2toA2intermediateA2zoneA2interneuronsA2=>A2extensorA2moto
neurons
-A2reflexA2operatesA2onlyA2duringA2stance

BabinskiA2signA2-A2Ans---
A2extensorA2thrustA2reflexA2isA2influencedA2byA2corticospinalA2tract
-A2canA2beA2elicitedA2atA2restA2(inA2theA2toes)A2byA2vigorousA2strokingA2ofA2soleA2ofA2foot
-
A2ifA2corticospinalA2tractA2isA2damagedA2(stroke,A2spinalA2injury),A2theA2reflexA2patternA2isA2
switchedA2toA2flexionA2withdrawal

Vestibulo-SpinalA2ReflexA2-A2Ans---
A2stimulus:A2downwardA2deviationA2ofA2headA2onA2oneA2sideA2=>A2activatesA2otolithA2affer
ents
-A2response:A2'downhill'A2limbsA2extend
-A2otolithA2afferentsA2activateA2lateralA2vestibulo-
spinalA2tract:A2ipsilateralA2projectionA2toA2extensorA2(antigravity)A2motorA2nuclei
-A2posturalA2reflexA2-A2reflexA2latencyA2inA2legsA2aboutA280ms

CPGA2-A2Ans--centralA2patternA2generators

CentralA2PatternA2GeneratorA2-A2Ans---
A2reflexesA2canA2performA2simpleA2elementsA2ofA2movements,A2butA2notA2complexA2patter
ns