week 12A

Question 1

A spinal reflex is a ___ erponse in reaciton to a ____

Answer 1

mtoro repsosne in reaction to sensory stimulus

Question 2

the stimuli in a spianl refelx is from___ and occurs whre>

Answer 2

from peripheral sensory recoptors and occurs entirely within spinal chrod

Question 3

what are the 3 basic components of a loop?

Answer 3

1. sensory neuron
2. internuron
3. motor neuron

Question 4

Which of the following is/are true about
muscle spindles?
A) They sense stretch
B) They sense muscle tension
C) They work to excite the agonist muscle
D) Both A & B
E) Both A & C

Answer 4

A and C

Question 5

spindle-mediated reflex is also referred to as s___

Answer 5

stretch reflex

Question 6

what elicits the response fo the stretch reflex and what is it mediated by?

Answer 6

elicited by muscle fibres being stretched (eg. tendon tap, tendon vibration)

Mediated by: msucle spindle s via 1a afferents - dorsal column medial lemnisacal tract

Question 7

what tract does the strech reflex take

Answer 7

medial lemniscal tract - dorsal column

Question 8

what is the goal of the spindle medited/stretc reflex

Answer 8

maintain muscle length

Question 9

what are the two simultaneous reflexes that comprise the spindle-mediated/stretch reflex

Answer 9

autogenic excitation and reciprocal inhibition

Question 10

in aurogenic excitation ____ afferents ___ onto ___ and ____

Answer 10

1a afferent diverge onto alpha MN of same muscle (agonsit) +
MN of synergists

Question 11

autogenic excitation is a ___synaptic reflex that projects on the ___ and __ msulces via ____

Answer 11

Monosynaptic - very fast

projects onto the motor neurons of agonist and syngergist muscles via i a afferent

Question 12

draw out the autogenic excitation pathway

Question 13

recipricol inhibition is involved in the ___ reflex and is ___ synaptic

Answer 13

strech/spindle reflex and is disynaptic

Question 14

recipricol inhibition is ___ synaptic because ___

Answer 14

disynaptic because it involves the Ia inhibitor interneuron

Question 15

Receipricol inhibiton facilitates ____ by_____

Answer 15

facilates activaion of the agonist. +snergist muscle by inhibiting the antagonist’s muscle

Question 16

draw out the reciprocal inhibition pathway

Question 17

What does recipricol inhibtion dp?

Answer 17

Assist in the spidle/stretch reflex by facilitating the activation of agonist and synergist muscle by inhibiting the antagonist muscles

does this by ia inhibtiory interneuron onto teh alpha MN of the antag musle

Question 18

Draw out both autogenic excitation and recipricol inhibtion. What reflex are these two apthways involved in>

Answer 18

involved in spindle/stretch reflex

Question 19

Which of the following is/are true about
Golgi tendon organs?
A) They sense muscle tension
B) They work to excite the agonist muscle
C) They work to inhibit the agonist muscle
D) Both A & B
E) Both A & C

Answer 19

E - both b and c

Question 20

Spinal refelexes (GTO) are medated by ____ and involve ___ afferents

Answer 20

mediated by GTO - Ib afferents

Question 21

spinal relexes mediated by GTOs are also reffered as the ____

Answer 21

Ib inhibition reflex

Question 22

what are spinal reflexes (GTO) elicited and mediated by/what pathways?

Answer 22

elicite dby active (self-generated_ tension in muscle fibres
Mediated by GTO via Ib afferents, ascend via dorsal colum medial lemniscal tract

Question 23

both spinal (GTO) and stretch refelxes ascned via the ___

Answer 23

dorsal columm of medial lemniscal tract

Question 24

what is the goal of the Ib inhibiton reflex

Answer 24

relax/inhibit muscle

Question 25

what 2 simultaneous reflex is the Ib inhibitory reflex comprised

Answer 25

autogenic inhibition reciprocal excitation

Question 26

IN autogenic inhibition ___ affferent go where, What relex?

Answer 26

Spinal refelx/ib inhibitory reflex - Ib afferents go to ib inhibitor interneuron - to alpha MN of agonist and inhibits agonist

Question 27

autogentic inhibtiion is a ___ reflex whereas autogenic exciation is a ___ reflex

Answer 27

autogenic inhibition is disynaptic and inhibits agonists - it is involved in the GIB inhibitory reflex autogenic excitation is involve in spindle/stretch refelx - it excites the agonist muscle via a nonsynaptic pathway - is faster.

Question 28

draw our autogenic inhibition and reciprocal excitation. What reflex is this involved in?

Question 29

Recipricol inhbition is involved in _____

Answer 29

facilitating relaxation/inihbitoin of agonist by activating the antagonist

Question 30

What happens in reciprocal excitation - what reflex is this involved in?

Answer 30

in recipricol excitation the antagonist is activated when the ib inhiboty interneuron diverges onto a another inhibtory internuron which projects onto the antagonist essential the Ib inhibtory itnernuron is ihibiting the inihbitor so ti activates teh antagonist

Question 31

how does recirpciol exciation happen?

Answer 31

antagonist is excited via inhibtion of inhibitor IB inhibitory interuneruon inhibits ihibtiion of antagonist

Question 32

Daredevil Paige is attending her annual check-up. Dr. Sasha checks her reflexes by tapping her patellar tendon What reflex is being tested What sensory afferent is activated List 2 pathways of this reflex 1) autogenic excitation 2) reciprocal inhibition

Answer 32

stretch refelx ia afferent autogenic excitation + recirpicol ihibiton

Question 33

recirpicol exciation is a ___synaptic pathway becaue ...

Answer 33

a polysynaptic bc it involves ib afferent onto ib inhib interneuron on inhib MN of antagonist

Question 34

Cutaneous mediated spinal reflexes also known as:

Answer 34

polysynaptic refelx pathways

Question 35

what are cutaneois mediated polysnaptic refelxes mediated and elicited y?

Answer 35

elicited by painful stimulus mediated by nocireceptors via A or C fibres, ascned via spinothalmic tract

Question 36

what tract do polysynaptic cutanous mediated reflexe pathways take?

Answer 36

spinothalmic

Question 37

what is the goal of cutaneous-mediated polysynaptic reflex pathways

Answer 37

to withdraw form the apinfuls timulus

Question 38

Polysynatpic, cutaneous mediated reflex pathways involve what 2 simualtenous reflexes?

Answer 38

crossed-extensory reflex flexor withdrawal refelx

Question 39

in the flexor (withdrawal) reflex ____ projexct to ____ whcih___

Answer 39

a fibres project to excitatory interneurons which excites the alpa motor neurons of the flexor A fibre also projects onto inhibitory interneurons which project to Allah MN of the extensor of the extensor Limb flexor - excited limb extensory - inhibited allows lexors to withdraw from pain

Question 40

when u step on a nail expliain how the flexor reflex is activatd

Answer 40

flexor muscle is activated to withdraw for pain - fibres go onto excitatory interneuron and excite the MN of hamstrings extensor muscle is inhibited - A fibres go onto inhib interneuron- inhibits alpa motor neurons of extensor - quads

Question 41

what is the crossed extensor refelx

Answer 41

opposite reaction in the opposite limb of flexor reflex

Question 42

what is the fucntion of the crossed-extensor reflex

Answer 42

stabilize the body so the other limb can move away from the pain

Question 43

how does the crossed extensor reflex work?

Answer 43

a fibres project onto excitatory interneuron which excites the alpha MN of extensors muscle (quads) a fibres project on inhibitory interneuron which inhibits the flexor alpha MN + muscle (hamstring)

Question 44

the flexors and crossed extensory reflex is mediated by ___ recptors and is a __ mechanism

Answer 44

protective mechanism o protect from pain and is mediated by cutaneous nociceptors ( a or c fibres) the flexor - withdraw from pain the crossed-extnsor - stabilzies other limb of bodu to allow withdraw from stimulus

Question 45

draw out the flexor and crossed-extensor reflex