Brainscape's Knowledge GenomeTM

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


See full index

physiology > spinal reflexes > Flashcards

spinal reflexes Flashcards

1
Q

name the three types of movement classifications

A
  1. simple reflexes
  2. rhythmic motor patterns
  3. voluntary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are examples of simple reflex types (generalised)

A

involuntary
rapid
stereotyped

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

what are examples of rhythmic motor patterns

A

combines voluntary + reflexive acts - walking, running, chewing
once initiated they are reflexive

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

what are examples of voluntary actions

A

complex- reading, writing
learned + purposeful

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

what three horns make up the grey matter of the spinal cord

A

dorsal horn
lateral horn
ventral horn

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

is the dorsal horn or ventral horn on the anterior side

A

ventral horn

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

does the dorsal root have a ganglion?

A

yes

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

which is responsible for flexion - the dorsal nerves or ventral nerves

A

dorsal

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

which is responsible for extension - the dorsal nerves or ventral nerves

A

ventral

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

what are Renshaw cells

A

interneurons involved in recurrent or feedback inhibition
-suppress weakly firing motor neurons
-dampens strongly firing ones to produce economical movement

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

what is the muscle spindle involved in (what is its role)

A

it identifies stretch
doesnt allow muscle to overstretch

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

what happens if a muscle stretches too far

A

gets damaged

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

how is the muscle spindle involved in proprioception

A

muscle spindle understands length of muscle and sends it to CNS so you know where limbs are at all times

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

what do afferent axons do

A

identify length and rate of stretch

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

what do gamma motor neurons do

A

modify set point of muscle spindle - change length not force!

sends it to spinal cord

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

what type of reflex is a myotatic (knee jerk) reflex

A

monosynaptic stretch reflex

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

what is a myotatic reflex

A

knee jerk reflex

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

what is the name of the afferent neuron involved in myotatic reflex (reflex)

A

la afferent

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

describe the pathway of a myotatic reflex (knee jerk) - there are 4 steps

A
  • tap of patellar tendon stretches quadriceps muscle
  • stimulates dynamic nuclear bag receptors of muscle spindle
  • increases rate of firing of la afferent leads to contraction of quadriceps muscle
  • la fibers also stimulate inhibitory interneurons which inhibits antagonistic (flexor) muscles of knee joint
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

the knee jerk reflex is lost if ______ are damaged

A

lower lumbar dorsal roots of spinal cord are damaged

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

what direction do reflexes travel through the spinal cord

A

in through the ganglion into the dorsal root, through into the ventral root

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

what are the two phases in the gait cycle?

A

right stance phase
right swing phase

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

what happens during the stance phase

A

foot touches the ground, flexion of knee and ankle
finishes with extension of all joints ready for forward movement

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

what happens during the swing phase

A

flexion of hip, knee + ankle
then knee and ankle extend

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

what is the definition of a central pattern generator

A

use lots of reflexes together to run in a repetitive motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how are central pattern generators modulated

A

via proprioceptive input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

is the central pattern generator capable of autonomous signals

A

yes

28
Q

where is the central pattern generator initated

A

in the mesencephalic locomotor region

29
Q

what does the output leave the central pattern generator through

A

reticular nuclei
reticulospinal tracts

30
Q

as a muscle extends, what does the muscle spindle inhibit

A

flexor muscles

31
Q

in the central pattern generator describe the pathway how flexor muscles are activated, starting from la afferent nerve

A

la afferent brings information from dorsal column to central pattern generator
activates the flexor MN pool
then the la inhibitory interneuron inhibits the extensor MN pool (crosses the ventral spinocerebellar tract)
.. also renshaw cells provide negative feedback, inhibit the flexor MN pool and extensor MN pool
then impulse travels to flexor muscles via dorsal column

32
Q

in the central pattern generator describe the pathway how extensor muscles are activated, starting from la afferent nerve

A

la afferent brings information from dorsal column to central pattern generator
activates the extensor MN pool
then the la inhibitory interneuron inhibits the flexor MN pool (crosses the ventral spinocerebellar tract)
.. also renshaw cells provide negative feedback, inhibit the extensor MN pool and flexor MN pool
then impulse travels to extensor muscles via dorsal column

33
Q

does the primary motor cortex (M1) supply muscles from the same side, opposite side, or both sides of the body

A

opposite side of the body

34
Q

what are the names of the 4 premotor cortical areas

A
  • supplementary motor area (SMA)
  • cingulate gyrus
  • ventral premotor cortex
  • dorsal premotor cortex
35
Q

does the supplementary motor area (one of the 4 premotor cortical areas) supply muscles from one or both sides of the body

A

both

36
Q

where does the basal ganglia receive excitatory input from

A

cerebral cortex

37
Q

where does the basal ganglia outputs go to

A

thalamus
spinal cord
cerebral cortex

38
Q

name the 5 parts of the basal ganglia

A

caudate
globus pallidus
subthalamic nucleus
substantia nigra
putamen

39
Q

what is the hyperdirect pathway - there are 4 steps

A

initial planned info from motor cortex → subthalamic nuclei → globus pallidus → inhibits thalamus to allow initiation of movement to occur

40
Q

describe the direct pathway

A

the striatum inhibits 1) the INTERNAL segment of globus pallidus 2) pars reticulata of substantia nigra
substantia nigra inhibits thalamus
thalamus stimulates motor cortex
!!! OVERALL input is EXCITATORY

41
Q

describe the indirect pathway

A

striatum inhibits the EXTERNAL segment of globus pallidus + subthalamic nucleus
subthalamic nucleus projects excitatory input to internal segment of globus pallidus, pars reticulata of substantia nigra -> the thalamus is inhibited
thalamus gives excitatory input to motor cortex
!!! OVERALL input is INHIBITORY

42
Q

what does the cerebellum do - what is its role

A

adjusts motor responses by comparing the intended output with sensory signals and to update movement commands if they deviate from the intended trajectory

43
Q

where does the cerebrocerebellum get its info from and what does it control

A

receives input from cerebral cortex, movement planning and initiation of movement

44
Q

where does the spinocerebellum get its info from and what does it control

A

receives input from the spinal cord about limb position, touch and pressure

45
Q

what does the vestibulocerebellum control

A

balance and eye movements

46
Q

what are the 3 peduncles names

A

superior
middle
inferior
—- peduncles

47
Q

the superior peduncle connects the ________ to the ________

A

the superior peduncle connects the CEREBELLUM to the MIDBRAIN

48
Q

what do the cerebellar peduncles all contain

A

efferent and afferent axons between cerebellum and CNS

49
Q

the middle peduncle connects the ________ to the ________

A

the middle peduncle connects the CEREBELLUM to the PONS

50
Q

the inferior peduncle connects the ________ to the ________

A

the inferior peduncle connects the CEREBELLUM to the MEDULLA

51
Q

the majority of afferent signals use which two peduncles for passage

A

middle and inferior peduncles

52
Q

the majority of efferent signals use which peduncles for passage

A

superior peduncle

53
Q

what is an afferent neuron

A

bring sensory info from the outside world to the brain

54
Q

what is an efferent neuron

A

carries signals from the brain to the PNS to initiate an action

55
Q

where do all descending motor pathways originate (except the corticospinal tract)

A

brain stem

56
Q

what are the 3 types of nuclei for postural control and locomotion

A
  • vestibular nuclei
  • red nucleus
  • reticular nuclei
57
Q

what are the names of the 5 brain areas that give rise to descending tracts

A

cerebral cortex
brainstem + medulla
— reticular formation
— vestibular nuclei
— red nucleus
— tectum

58
Q

what descending tract does the cerebral cortex give rise to

A

the corticospinal tract

59
Q

in the brainstem + medulla, what descending tracts do:
— reticular formation
— vestibular nuclei
— red nucleus
— tectum
give rise to. (there is 1 for each bullet point)

A
  1. reticular formation
    reticulospinal
  2. vestibular nuclei
    vestibulospinal
  3. red nucleus
    rubrospinal
  4. tectum
    tectospinal
60
Q

muscle motor pathway lesion what is it involved in and what change occurs if it goes wrong

A
  • normal reflexes
  • weakness/wasting
    eg - myositis, muscular dystrophy
61
Q

neuromuscular junction (motor pathway lesion) what is it involved in and what change occurs if it goes wrong

A
  • normal reflexes
  • normal muscle bulk
  • fatigable weakness
    eg - myasthenia gravis
62
Q

how are upper motor neurons most likely to be damaged

A

cerebral vascular accident, spinal cord trauma

63
Q

how are lower motor neurons most likely to be damaged

A

motor neurone disease, neuropathy

64
Q

cerebellum (motor pathway lesion) what is it involved in and what change occurs if it goes wrong

A

normal reflexes, strength,
- slight decrease in tone
-incoordination, multiple sclerosis

65
Q

basal ganglia (motor pathway lesion) what is it involved in and what change occurs if it goes wrong

A

movement changes
- parkinson’s, huntington’s

physiology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions