Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BMB Test 1 > B7-017 Spinal Cord Reflexes > Flashcards

B7-017 Spinal Cord Reflexes Flashcards

1
Q

predominant stretch receptors in muscle

A

muscle spindles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

composed of intrafusal fibers

A

muscle spindles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

muscle spindles lie in […] with extrafusal fibers

A

parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the rapidly adapting (dynamic) component of muscles spindles provides info about

A

velocity of stretch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the slowly adapting (static) component of muscles spindles provides info about

A

length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

muscle spindle innervation contributes to muscle […]

A

tone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

monitor stresses and forces at the tendon

A

golgi tendon organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

GTOs lie in […] with extrafusal fibers

A

series

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

innervated by Ib afferents only

A

GTOs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

conscious proprioception goes through the […] pathway

A

DC/ML

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

unconscious proprioception goes through the […] pathway

A

spinal cord and cerebellar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

pathway the regulates balance and smoothing movements of unconscious proprioception

A

spinocerebellar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

motor units contract the muscle […] a motor neuron fires

A

every time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

have characteristic innervation ratio

A

motor units

fine control requires lower ratio than coarse control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

a lesion in one segment of the ventral horn will result in motor deficits to

A

several muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

2 mechanism to increase force to motor neuron

A

increase firing rate
increase number of motor units firing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

order of recruitment

A

small motor units recruited first, follwed by larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

small slow motor units

A

type 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

endurance motor units

A

type 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

large fast motor units

A

type II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

motor units that convey large forces for a short time {sprint}

A

type 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

oxidative motor unit
lots of mitochondria

A

type 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

glycolytic motor unit
few mitochondria

A

type 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

red motor unit

A

type 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

white motor unit

A

type 2

26
Q

afferent coming from one muscle
efferent going into same muscle

A

homonymous

27
Q

afferent coming from one muscle
efferent goes to opposing muscle

A

heteronymous

28
Q

describe the sequence of events in the stretch reflex

A
  1. tendon tapped, muscle is stretched
  2. muscle spindle is stretched
  3. Ia and II nerve ending are deformed
  4. sensory nerve endings depolarized
  5. increased firing of Ia and II efferents
  6. excitation of alpha motor neurons
  7. increased firing of alpha motor neurons
  8. contraction of the muscle
29
Q

Ia afferent detects change in velocity/length of muscle and sends quick activation signal to the Ia afferent nerve

A

dynamic “knee jerk” phase of stretch reflex

30
Q

[…] phase of reflex is important to maintain muscle tone

A

tonic

(cutting the Ia afferents would greatly reduce tension)

31
Q

adjust the gain (length) of the muscle spindles to continuously provide information about the length/stretch to the PNS

A

gamma motor neurons

32
Q

activated by stretching a spastic or rigid muscle
contraction, then rigidity “melts away”

A

inverse stretch reflex

33
Q

inverse stretch reflex is mediated by

A

GTO/Ib afferent

34
Q

stretch reflex is mediated by

A

muscle spindles

35
Q

activated by increased stretch
increasing muscle contraction

A

stretch reflex

36
Q

initiated from cutaneous stimuli to remove body from potentially damaging stimuli

A

flexion reflex

37
Q

contralateral component of the flexion reflex that helps to maintain balance

A

crossed extensor reflex (crosses the midline)

38
Q

two stages of reflexes after spinal injury

A
  1. hyporeflexive due to spinal shock (1-2 weeks)
  2. hyperreflexive due to loss of inhibition of LMN
39
Q

how do muscle spindles send signals to the cerebellum to create balanced, smooth movements?

A
  1. muscle spindle afferent synapses at Dorsal Clarke nucleus
  2. second order axons ascend via dorsal spinocerebellar tract to ipsilateral cerebellum
40
Q

striking the tendon with a reflex hammer stretches both […] and […] muscle fibers

A

extrafusal
intrafusal

41
Q

in the stretch reflex, greater force causes greater stretch, which causes greater activation of […] in the muscle spindle

A

Ia afferents

results in greater muscle contraction

42
Q

causes you to extend your contralateral limb after your ipsilateral limb is flexed to try to maintain balance

A

crossed extensor reflex

43
Q

DTR is initiated by

A

stretch

44
Q

cutaneous afferents in the skin that sense somatosensory stimuli and elicit a protective response

A

flexor reflex afferents

example: Babinski’s

45
Q

examples of flexor reflex afferents [3]

A

Babinski’s
flexion (withdrawal) reflex
corneal blink reflex

46
Q

sensory component of the inverse stretch reflex

A

GTOs

47
Q

the flexor withdrawal reflex is initiated by noxious stimuli carried on what fibers?

A

C and A-delta fibers

48
Q

conveys proprioceptive information to the ipsilateral cerebellum to smooth out movements

A

spinocerebellar

49
Q

the dorsal spinocerebellar pathway in the spinal cord conveys proprioceptive information to the […] cerebellum

the cerebellum then communicates with the […] motor cortex to correct motor instructions to affected limb

A

ipsilateral

contralateral

50
Q

carries pain and temperature information

A

spinothalamic tract

51
Q

sudden release of muscle tension when GTOs signal too much stress at the tendon

A

inverse stretch reflex

52
Q

maintaining a contraction is stimulated by […] afferents

A

Ia

53
Q

[…] afferents inhibit the alpha motor neuron to relax the muscle

A

Ib

54
Q

force at the tendon is measured by […] afferents in the GTO

A

Ib

55
Q

responsible for altering the length of the muscle spindle intrafusal motor fibers

A

gamma afferents

56
Q

[…] fibers mediate pain that stimulates the withdrawal reflex

A

A-delta
C fibers

57
Q

number of muscle fibers innervated by a given motor axon

A

innervation ratio

58
Q

for imprecise movements requiring large force the innervation ratio is […]

A

high

(1 motor neuron activates many muscle fibers simultaneously to generate force)

59
Q

for fine, precise movements the innervation ratio is […]

A

low

(small groups of muscle fibers controlled individually for greater control)

60
Q

both firing rate and orderly recruitment by size are mechanisms for

A

increasing force

61
Q

inhibition of […] fibers is useful to provide coordinated movements

A

heteronymous

BMB Test 1 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions