neuro lab reflexes

Question 1

where are muscle spindles located

Answer 1

located deep w/in the muscle belly

Question 2

what do muscle spindles detect

Answer 2

sensitive to stretch or change in muscle length

Question 3

what is the significance of muscle spindles in the jerk response

Answer 3

when muscle is stretched the muscles spindles are also stretched hence activating Ia fibers in the spindle

these fibers synapse directly with the efferent motor neuron in SC there by eliciting a contraction in response to stretch stimulus

stretch in muscle spindle = contraction of same muscle

Question 4

what do GTO detect

Answer 4

degree of tension or the contraction of a muscle

Question 5

what is the significance of GTO

Answer 5

if tension is too high it will trigger Ib fibers of the GTO to send signal received by the inhibitory interneuron in the SC which synapses c efferent motor neuron causing the muscle to relax

tension in muscle = relaxation of muscle

Question 6

what is the structure of an intrafusal m fiber

Answer 6

central (dilated) - non contractile portion

polar ends - contractile portion

Question 7

what is the structure of the central portion

Answer 7

has 2 large myelinated afferent nerve fibers

Ia - annulospiral
II - flowerspray

Question 8

what does the Ia fibers detect

Answer 8

static and dynamic stretch bcs present in both nuclear bag and nuclear chain

Question 9

what does the II fibers detect

Answer 9

static stretch only bcs connected lang sha c nuclear chain

Question 10

what is the significance of nuclear bag and chain

Answer 10

NB - for dynamic response

NC - static response

Question 11

what is the structure of the polar ends

Answer 11

may gamma motor efferent fibers

Question 12

in what fiber is dynamic stretch present

Answer 12

Ia only bcs NB

Question 13

in what fiber is static stretch present

Answer 13

Ia and II bcs NC

Question 14

compare intra and extra fusal m fibers in terms of nuerons present

Answer 14

intra - gamma

extra - alpha

Question 15

examples of dynamic stretch

Answer 15

DTR and sudden stretch

Question 16

stretching used if there are contractures

Answer 16

positional stretching

Question 16

examples of static stretch

Answer 16

usual na stretching; slow

Question 17

explain the process of stretch reflex

Answer 17

lengthened muscle = excites NB and NC - type Ia and II to signal SC

signal goes to SC and synapse c DRG = coactivation of gamma and alpha motor neuron

gamma - gives efferent signal to polar end if IMF
alpha - stimulate EMF

= muscle contracts

Question 18

explain the process of inverse stretch reflex

Answer 18

when muscle contracts = tension = GTO stretch on both sides = Ib fibers stimulated

Ib fibers synapse c DRG = alpha motor neuron will be inhibited = no signal to extrafusal

= muscle does not contract = relax

Question 19

explain autogenic inhibition

Answer 19

GTO - relax of agonist; contraction of antagonist

Question 20

explain reciprocal inhibition

Answer 20

muscle spindle - contraction of agonist; relax antagonist

Question 21

what is monoreflex and give an example

Answer 21

one pathway lng daan gang spinal cord lang - knee jerk

Question 22

what is polyreflex and give an example

Answer 22

aakyat pa reflex sa brain ma pprocess gannun may multiple pathways - withdrawal reflex

Question 23

what is arreflexia

Answer 23

pure absence of DTR - cut both efferent and afferent pathways

Question 24

what is hyporeflexia

Answer 24

diminished reflex - may blockage lng sa conduction

Question 25

what is hyperreflexia

Answer 25

very brisk or conus reflex - UMN lesion maaffect corticospinal tract so ma sstop conductio of renshaw cells that will inhibit or control the reflex

Question 26

explain conus reflex

Answer 26

rhythmic involuntary contraction - spasticity usually seen in stroke patients

Question 27

significance of jendrassik maneuver

Answer 27

will elicit true reflex kase mappunta renshaw sa upper half ng body

Question 28

what are primitive reflexes

Answer 28

survival reflex and can be seen sa bata or sa stroke pt

Question 29

what are physiological reflex

Answer 29

survival reflex of adults

Question 30

what is palmomental reflex

Answer 30

primitive reflex - twitch yung chin when stroked thenar eminence of palm