Motor

Question 1

what type of organisation does the sensorimotor system have

Answer 1

hierarchically organised

Question 2

give an example of a voluntary movement

Answer 2

run or walk

Question 3

which is the highest level of the sensorimotor cortex

Answer 3

association cortex

Question 4

where does the lower motor neuron project to

Answer 4

project to muscle

Question 5

what is the motor control system made up of

Answer 5

upper and lower neurons = integrated system

Question 6

where does the upper motor neuron project to

Answer 6

project to lower neurons

Question 7

how does info flow in the sensorimotor system

Answer 7

info flow down in the hierarchy

decend control

Question 8

how does the feedback system flow in the sensorimotor system

Answer 8

ascending system up to highest level of association cortex

Question 9

give an example of an involuntary movement

Answer 9

blinking

Question 10

what is at the lowest level of the sensorimotor system

Answer 10

motor neurons

Question 11

state 3 types of muscle

Answer 11

cardiac
smooth
skeletal

Question 12

what is the biggest muscle in the body

Answer 12

gluteaus maximus

Question 13

what is the smallest muscle in the body

Answer 13

stapedius - inner ear

Question 14

what is the strongest muscle in the body

Answer 14

masseter - jaw

Question 15

how is muscle movement achieved

Answer 15

antagonist arrangement - combined coordinated action of contract and relax

Question 16

what percentage of body weight do muscles compose

Answer 16

40%

Question 17

what is the role of overlapping filaments in muscles fibres

Answer 17

form mechanism which allows contracting and relaxing

Question 18

which chemicals allow transfer at myosin cross bridge cycle

Answer 18

calcium ions
magnesium
atp

Question 19

what processes occur at the myosin cross bridge cycle

Answer 19

the overlapping filaments of the long axis of muscles fibres contract and stretch
chemical exchange

Question 20

what is a motor unit

Answer 20

single alpha motor neuron and all muscle fibres it would activate

Question 21

how do you generate greater movement resolution

Answer 21

use of fewer muscle fibres

Question 22

what does the motor pool contain

Answer 22

contain alpha and gamma neurons

Question 23

what is the shape of the motor pool

Answer 23

rod shaped

ventral horn of spinal cord

Question 24

what is the function of alpha neurons

Answer 24

innervate EXTRAFUSAL MUSCLE fibres of SKELETAL MUSCLE

Question 25

What is the function of gamma neurons

Answer 25

innervate INTRAFUSAL muscle of muscle spindles

Question 26

what is the cell body in the ventral horn activated by

Answer 26

sensory info from muscle and brain

Question 27

what 2 pieces of info must the CNS know to control muscles contracting and relaxing

Answer 27

1. tension of muscle | 2. muscle length

Question 28

where is the Golgi tendon located

Answer 28

tendon

Question 29

what is the function of the Golgi tendon

Answer 29

processes sensory information about tension of muscle | eg. how much force needed for muscle

Question 30

what does the Golgi tendon do in response to extreme tension

Answer 30

Golgi tendon inhibit muscle fibres to prevent damage

Question 31

what is the function of muscle spindles

Answer 31

process info on muscle length/stretch

Question 32

what are extrafusal muscle fibres innervated by

Answer 32

alpha neurons

Question 33

what are intrafusal muscle fibres innervated by

Answer 33

gamma neurons

Question 34

what is the aim of muscles spindles to achieve

Answer 34

set optimum length of muscle stretch

Question 35

what is the role of muscle spindle feedback

Answer 35

info on muscle stretch - form efficient motor system

Question 36

what is coiled in intrafusal muscles

Answer 36

sensory fibres

Question 37

what is the role of sensory fibres in intrafusal muscles

Answer 37

keep intrafusal fibres at ideal length to optimise muscle strength

Question 38

what happens to the action potential when a muscle stretches

Answer 38

action potential rate increases

Question 39

what happens if only alpha motor neurons generate an action potential

Answer 39

extrafusal muscle contracts | muscle becomes slack - no more AP generated

Question 40

what happens during coactivation of alpha and motor neurons

Answer 40

extrafusal and intrafusal muscle fibres contract

Question 41

what is the advantage of acoactivation of alpha and motor neurons

Answer 41

tension maintained in muscle

Question 42

what type of reflex is a withdrawal reflex

Answer 42

complex reflex

Question 43

define recipricoal innervation

Answer 43

antagonistic muscle contracts and another muscle would relax

Question 44

what is the role of the complex reflex system

Answer 44

respond to stretch of muscle fibres

Question 45

what is the number of muscle fibres dependent on

Answer 45

level of control and stretch of muscle

Question 46

what is the advantage of slow muscles fibres

Answer 46

they won't fatigue

Question 47

state 3characteristics of fast muscle fibres

Answer 47

1. can fatigue 2. quick 3. fewer blood vessels

Question 48

what is meant by the size principle in the motor system

Answer 48

muscle recruited in size order

Question 49

why are muscles recruited in size order?

Answer 49

smallest first | fine control of muscles at lower levels

Question 50

where does the motor cortex project to

Answer 50

lower motor neurons

Question 51

which 2 brain components feed back to the cortex

Answer 51

basal ganglia and cerebellum

Question 52

what is the role of the homunculus

Answer 52

contains representations of the complex and overlapping motor commands

Question 53

state the hierachial processes of the motor system

Answer 53

1. association cortex 2. primary motor cortex 3. brain stem motor nuclei 4. spinal motor cortex

Question 54

why is the ancient brain stem motor control sophisticate

Answer 54

evolutionary changes promote survival

Question 55

state the 2 types of ventromedial tracts

Answer 55

1. ventromedial corticospinal tract | 2. ventromedial corticobrain-stem spinal tract

Question 56

what does the ventromedial corticospinal tract project to

Answer 56

trunk and limb muscles

Question 57

state 2 characteristics of the ventromedial cortico brain stem spinal tract

Answer 57

1. one way organisation | 2. bilateral projections

Question 58

what 5 components make up the basal ganglia

Answer 58

1. globus palllidus 2. putamen 3. caudate nucleus 4. thalamus 5. substantia nigra

Question 59

what is the role of the thalamus in the basal ganglia

Answer 59

output information would be relayed back to cortex

Question 60

which basal ganglia component feeds info to the globus pallidus and substantia nigra

Answer 60

subthalamic nucleus

Question 61

which 2 basal ganglia components make up the striatum

Answer 61

putamen and caudate

Question 62

what is the flow of information in the basal ganglia

Answer 62

cerebral cortex - striatum - globus pallidus and substantia nigra - thalamus

Question 63

what happens if the basal ganglia is removed

Answer 63

unable to select motor commands

Question 64

what is the selecting problem in the basal ganglia

Answer 64

mutiple commands processed in parallel | all processed through same motor pathway

Question 65

what is the basal ganglia defined as

Answer 65

central action selector

Question 66

describe the motor actions of the basal ganglia at rest

Answer 66

1. no activity in striatum at rest 2. tonically active in globus pallidus 3. thalamus in inhibited 4. low levels of excitation in motor cortex

Question 67

what happens when the basal ganglia is excited

Answer 67

striatum is excited | thalamus is disinhibted meaning higher excitation in output to lower motor neurons

Question 68

what causes the excitement in the striatum

Answer 68

dopamine input from substantia nigra cause transcient inhibition

Question 69

what is the role of the cerebellum

Answer 69

regulate activity of upper motor neurons

Question 70

what is cerebral angesis

Answer 70

a brain which does not have a cerebellum

Question 71

what is dysarthia

Answer 71

disruption of control of speech

Question 72

how does the cerebellum regulate motor activity

Answer 72

aware of motor commands and project to motor cortex

Question 73

state some symptoms of a damaged cerebellum

Answer 73

1. poor coordination 2. loss of voluntary movement 3. jerky movements

Question 74

what are the 3 regions which regulate input and output of the cerebellum

Answer 74

1. corticol 2. spinal 3. vestibular

Question 75

what is the vestibular region of the cerebellum responsibe for

Answer 75

head movements

Question 76

what is the spinal input and output of the cerebellum

Answer 76

stimuli on limbs and movement | eg. muscle spindles

Question 77

name the 2 types of dorsolateral tracts

Answer 77

1. dorsolateral corticospinal tract | 2. dorsolateral corticorubospinal tract

Question 78

what is the flow of info through in the dorsolateral corticospinal tract to

Answer 78

tract via medullary pyrmaid to contralateral limb muscles

Question 79

state characteristics of the dorsolateral corticorubospinal tract

Answer 79

via red nucleus | tract to cranial nerves of facial muscles

Question 80

what type of projections are both the dorsolateral tracts

Answer 80

contralateral

Question 81

which tract is an indirect route

Answer 81

ventromedial cortico brain stem spinal tract