Spinal level reflexes

Question 1

Stretch (myotatic) reflexes - Stimulus =

Answer 1

muscle stretch

Question 2

Stretch (myotatic) reflexes - Reflex arc =

Answer 2

afferent 1a fiber from muscle spindle to alpha motor neurons projecting back to muscle of origin (monosynaptic)

Question 3

Stretch (myotatic) reflexes - Functions for…

Answer 3

maintenance of muscle tone, support agonist muscle contraction, and provide feedback about muscle length

Question 4

Stretch (myotatic) reflexes - clinically tested how

Answer 4

applying stretch to deep tendons

Question 5

Stretch (myotatic) reflexes - recirprocal inhibition =

Answer 5

via inhibitory interneurons, the same stretch stimulus inhibits the antagonist muscle

Question 6

Stretch (myotatic) reflexes - reciprocal innervation describes

Answer 6

the effects of a stretch stimulus on agonist (autogenic facilitation), antagonist (reciprocal inhibition), and synergistic muscles (facilitation)

Question 7

Inverse stretch (myotatic) reflex - Stimulus =

Answer 7

muscle contraction

Question 8

Inverse stretch (myotatic) reflex - reflex arc =

Answer 8

afferent 1b fibers from GTO via inhibitory interneuron to muscle of origin (polysynaptic)

Question 9

Inverse stretch (myotatic) reflex - Functions to..

Answer 9

provide agonisr inhibition, dimiution of force of agonist contraction, stretch-protection reflex

Question 10

Gamma reflex loop - what forms part of this loop

Answer 10

stretch reflex

Question 11

Gamma reflex loop - does what

Answer 11

allows muscle tension to come under control of descending pathways
Descending pathways excite gamma motor neurons causing contraction of mm spindle and in turn inc stretch sensitiviity and inc rate of firing from spindle afferents
impulses are then conveyed to alpha motor neurons

Question 12

Flexor (withdrawal) reflex - stimulus =

Answer 12

cutaneous sensory stimuli

Question 13

Flexor (withdrawal) reflex - reflex arc

Answer 13

cutaneous receptors via interneurons to largely flexor muscles
multisegmental response involving groups of muscles (polysynaptic)

Question 14

Flexor (withdrawal) reflex - Functions as

Answer 14

protective withdrawal mechanism to remove body part from harmful stimuli

Question 15

Crossed extension reflex - stimuli

Answer 15

noxious stimuli and reciprocal action of antagonists

flexors on one side are excited, causing extensors on same side to be inhibited - opposite responses in opposite limb

Question 16

Crossed extension reflex - reflex arc

Answer 16

cutaneous and muscle receptors diverging to many spinal cord motor neuron on same and opp side (polysynaptic)

Question 17

Crossed extension reflex - function to

Answer 17

coordinate reciprocal limb activities like gait