Motor

Question 1

What are the two MODULATORS of the sensorimotor system?

Answer 1

Cerebellum

Basal ganglia

Question 2

Sensory information feeds back into…

Answer 2

Cerebellum

Basal ganglia

Question 3

Motor command originates in which cells?

Answer 3

Motor cortex pyramidal cells

Question 4

The descending projection from pyramidal cells –> spinal corn/lower motor neurons is known as

Answer 4

Pyramidal tract

Question 5

Cerebellum is ______, whereas basal ganglia are _______

Answer 5

Excitatory

Inhibitory

Question 6

Motor cortex is mapped as a ________

Answer 6

Homunculus

Question 7

Motor is delivered through

Answer 7

Motor units (small number of muscle fibres associated)

Question 8

2 main tracts descending from the motor cortex…

Answer 8

Dorsolateral

Ventromedial

Question 9

Both the dorsolateral and ventromedial tracts contain an indirect route via

Answer 9

Brainstem nuclei

Question 10

Basal ganglia dysfunction is implicated in many disorders, e.g.

Answer 10

Parkinson’s

Question 11

Basal ganglia nuclei inhibit the _______

Answer 11

Thalamus

Question 12

Basal Ganglia

Strong inhibitory (____) output goes back to cortex via thalamus

Answer 12

GABA

Question 13

Neural signals are conducted from the PMC to the neurons of the spinal cord in 4 different ways…

Answer 13

2 pathways in the dorsolateral region

2 pathways in the ventromedial region

Question 14

A notable neuron in the Dorsolateral corticospinal tract is…

Answer 14

Bet cells

Question 15

Is the dorsolateral corticospinal tract direct or indirect?

Answer 15

Direct

Question 16

The dorsolateral corticospinal tract is a group of axons that….

Answer 16

Depends from the PMC (through the medullary pyramids ) into spinal white matter

Question 17

dorsolateral corticospinal tract

Many of the axons synapse for the main neurons going to…

Answer 17

Wrist/hand/fingers/toes

Question 18

The dorsolateral corticospinal tract is found in all mammals who are…

Answer 18

Capable of moving fingers and toes

Question 19

dorsolateral corticospinal tract

Route?

Answer 19

PMC –> Medulla (Betz cells) –> interneurons in spinal cord

Question 20

Out of the dorsolateral tracts, which is the indirect route?

Answer 20

Dorsolateral cortico-rubro-spinal

Question 21

Dorsolateral cortico-rubro-spinal

group of axons which descend from the PMC synapse in….

Answer 21

The red nucleus of midbrain

Question 22

Dorsolateral cortico-rubro-spinal

Route?

Answer 22

PMC –> red nucleus –> interneurons in dorsolateral region (arms and legs)

Question 23

What are motor units?

Answer 23

Smallest unit of motor activity

Comprised of a single neuron and all the fibres it innervates

Question 24

Motor units

When the neuron fires, the muscle fibres…

Answer 24

That the neuron innervates contracts

Question 25

Motor units The less fibres attached to the neuron...

Answer 25

The more control there is over the muscle

Question 26

A skeletal muscle contains thousands of fibres bound together by a tough membrane called

Answer 26

Tendon (also holds it to the bone)

Question 27

Acetycholine, released at motor junctions, activates the

Answer 27

Motor end plate on each fibre

Question 28

"The only way for a muscle to generate force"

Answer 28

Contraction

Question 29

Fast muscle fibres (2)

Answer 29

Contract quickly | Great force

Question 30

Why do fast muscle fibres fatigue quickly?

Answer 30

Poorly vascularised

Question 31

Slow muscle fibres (1)

Answer 31

Capable of sustained activity

Question 32

Each muscle has both ____ and ____ fibres

Answer 32

Fast | Slow

Question 33

Which neurotransmitter is released at motor junctions?

Answer 33

Acetylcholine

Question 34

Flexors

Answer 34

Bend/flex a joint

Question 35

Extensors

Answer 35

Act to strengthen out/extend

Question 36

The bicep is a

Answer 36

Flexor

Question 37

The tricep is a

Answer 37

Extensor

Question 38

Synergistic muscles

Answer 38

2 muscles whose contraction produces the same movement

Question 39

Antagonistic muscles

Answer 39

2 muscles who's contraction produces opposite movements (biceps + triceps)

Question 40

TENSION in a muscle can be created by (3)

Answer 40

Increasing number of motor neurons in pool Increasing firing rate of neurons in pool Combination

Question 41

Golgi tendon organs respond to increases in

Answer 41

Muscle tension

Question 42

Golgi tendon organs DON'T respond to increases in

Answer 42

Length

Question 43

Muscle spindles respond to changes in

Answer 43

Length

Question 44

Muscle spindles DON'T respond to changes in

Answer 44

Muscle tension

Question 45

The skeletal muscle is a ________ muscle

Answer 45

Extrafusal

Question 46

Without this, the spindles would become slack/unresponsive whenever the extrafusal muscle contracts.

Answer 46

Intrafusal muscle/intrafusal motor neuron

Question 47

"Antagonistic muscles are innervated in a way that permit smooth, unimpeded motor response"

Answer 47

Reciprocal innervation

Question 48

"Each motor neuron branches out to an inhibitory interneuron before it leaves the spinal cord/CNS to give that muscle fibre a break"

Answer 48

Recurrent lateral inhibition