L9 make things happen

Question 1

What do efferent nerves do?

Answer 1

Carry impulses away from the central nervous system

Question 2

Where do efferent nerves end?

Answer 2

Either on muscles or on glands

Question 3

What are the 3 types of muscles?

Answer 3

Smooth
Cardiac
Skeletal

Question 4

Skeletal muscles are under what’s direct control?

Answer 4

CNS

Question 5

How many skeletal muscles are there in a human body?

Answer 5

Around 640

Question 6

Where does muscle sit in a complex motor system?

Answer 6

At the end

Question 7

What kind of connections do skeletal muscles have with the motor system?

Answer 7

Feed-forward and feed-back connections

Question 8

What are skeletal muscles made of?

Answer 8

Muscle fibres

Question 9

Each muscle fibre receives input from how many spinal motor neurons?

Answer 9

One

Question 10

Where do spinal motor neuron cell bodies live?

Answer 10

In the ventral horn of the spinal cord

Question 11

How many fibres do one spinal neuron contact?

Answer 11

Several

Question 12

What is a motor unit?

Answer 12

All muscle fibres supplied by one motor neuron

Question 13

When will fibres perform a short contraction?

Answer 13

Each time the motor neuron fires an action potential

Question 14

Why skeletal muscles are called striate?

Answer 14

It contains alternating stripes of actin and myosin filaments

Question 15

Consequence of nerve fibre activation.

Answer 15

Firing action potentials along the muscle fibre membrane and trigger Ca++ release

Question 16

What does firing action potentials allow?

Answer 16

Allows myosin proteins to latch on to actin fibres, leading to contraction

Question 17

What will happen if there is no further inputs from nerve fibre activation?

Answer 17

Ca++ is reabsorbed, myosin let go of the actin and the muscle relaxes

Question 18

What does myofibrils made of?

Answer 18

Protein filaments

Question 19

What does sarcoplasmic reticulum contain?

Answer 19

Ca++ ions and voltage gated Ca++ channels

Question 20

When the muscle is at rest, what happens to the myosin binding site?

Answer 20

It will be covered up by tropomyosin (protein)

Question 21

What happens when actin and myosin are not attached when the muscle is at rest?

Answer 21

Actin and myosin will slide past each other and the muscle will become longer

Question 22

What makes tropomyosin leave?

Answer 22

Ca++

Question 23

When myosin head bends backwards, what does it release and what does it do?

Answer 23

ADP and myosin head pulls itself forward

Question 24

What causes a release from actin?

Answer 24

ATP binding to myosin

Question 25

Before myosin ready to undergo new binding cycle and pulling cycle, what does it do?

Answer 25

Myosin uses energy from ATP hydrolysis to stretch itself

Question 26

What do skeletal muscles contain?

Answer 26

Muscle fibres and spindles which incorporate stretch receptors

Question 27

How does stretch receptors send signals back to the spinal cord?

Answer 27

Through fast conducting A-beta fibres

Question 28

Gamma motor neurons control what kind of contractions?

Answer 28

Muscle spindle contractions

Question 29

What does alpha motor neurons control?

Answer 29

Ordinary muscle fibres

Question 30

How can muscle spindle afferents form monosynaptic reflex arcs in the spinal cord?

Answer 30

Muscle spindle afferents connect straight to alpha motor neurons

Question 31

What are muscle spindles?

Answer 31

Receptors for muscle stretch in the two-neuron stretch reflex (stretch receptors within the body of a skeletal muscle that primarily detect changes in the length of the muscle)

Question 32

Other than simple, direct connection, what are the other connections that allow reflex to serve postural control function?

Answer 32

Synergistic and inhibitory

Question 33

Muscles can only ____ (pull, push, contract)

Answer 33

Pull & contract

Question 34

Muscle contracted, stretched

Answer 34

Agonist, extensor

Question 35

Muscle relaxed, bending a limb

Answer 35

Antagonist, flexor

Question 36

Other than stretch receptors, reflexes can also be triggered by? Name 2 sample reflex

Answer 36

Sensory afferents | nociceptive withdrawal reflex, pupillary light reflex

Question 37

With the 'reflex' theory of nervous system we mean that

Answer 37

The nervous system is entirely reactive to external stimuli

Question 38

Simple spinal motor circuits can sometimes exhibit ______ patterned activity. Give an example.

Answer 38

spontaneous; central pattern generators

Question 39

What is often predictive rather than reactive to external stimuli? and what does it depend?

Answer 39

Motor control; context (the 'cognitive state' of the subject)

Question 40

What can isolated spinal cords able to do?

Answer 40

Orchestrating complex movements

Question 41

Can spinal cord orchestrating complex and intricate movement patterns?

Answer 41

Yes

Question 42

Primary motor cortex (M1) connects directly to ___________ via the _________

Answer 42

Spinal motor neurons; cortico-spinal tract

Question 43

Name the motor related areas of cortex. (6)

Answer 43

``` Frontal eye fields Supplementary motor area Primary motor cortex Somatosensory cortex Broca's area Premotor area ```

Question 44

What is Penfield's Homunculi? (recognise)

Answer 44

A distorted representation of the human body, based on a neurological "map" of the areas and proportions of the human brain

Question 45

Which 3 cortex have a somatotopic organisation?

Answer 45

Primary, supplementary and premotor cortex

Question 46

How are the primary, supplementary and premotor cortex tuned?

Answer 46

Movement direction tuned

Question 47

What do primary, supplementary and premotor cortex collaborate with to compute movement intentions?

Answer 47

Basal ganglia and the spinal cord

Question 48

How are overall movement direction is specified?

Answer 48

By a 'population vector' which weights preferred direction of each neuron by how strongly it is activated

Question 49

How can population vectors can be 'read out' in real time?

Answer 49

With multi-electrode arrays

Question 50

Reading out population encoding of motor intention makes what possible?

Answer 50

Brain-machine interfaces

Question 51

Where does the cortico-spinal tract originate?

Answer 51

The deep layers of M1

Question 52

Instead of specifying which motor unit to contract, how do neurons encode movement?

Answer 52

Encode the direction to move a limb in

Question 53

Which areas specify co-ordinated movements involving more than one muscle or limb?

Answer 53

Supplementary and pre-motor areas

Question 54

Which cortex contains mirror neurons?

Answer 54

Pre-frontal cortex

Question 55

What do the mirror neurons do?

Answer 55

Encode 'actions' irrespective of who the action is performed by

Question 56

Which side does the Broca's area lateralise?

Answer 56

To the left

Question 57

What does the Broca's area do?

Answer 57

Produce grammatical speech

Question 58

Damage to Broca's leads to __________ while leaving the ability to _______ intact.

Answer 58

motor aphasia; understand speech

Question 59

Wernicke's area is not well defined, but which part does it involve?

Answer 59

Boundary of the superior temporal and parietal area on the left hemisphere

Question 60

Which area is more responsible for speech understanding?

Answer 60

Wernicke's area

Question 61

Broca's aphasia is usually associated with lesion to the __________

Answer 61

left frontal cortex

Question 62

What is the name of the big fibre bundle that connects Broca's and Wernicke's area?

Answer 62

Arcuate Fasciculus

Question 63

The further up you go the motor hierarchy, the _____ activity will precede the _______

Answer 63

more; actual movement initiation

Question 64

Already in the ________ you can get electrical activity as much as half a second prior to a spontaneous, self-timed movement. (bereitschaftspotential/ _____)

Answer 64

supplementary motor area; readiness potential

Question 65

If electrically stimulate M1, people will_______.

Answer 65

feel their limbs are being moved

Question 66

If stimulate _______, they feel they want to move

Answer 66

supplementary motor areas