Block 5 - Categories of movement

Question 1

What is a reflex?

Answer 1

Involuntary motor response in response to a stimulus in the peripheral

Question 2

What is the afferent neuron carrying sensory info to the spine in a stretch reflex?

Answer 2

1a afferent

Question 3

How many neurons form a monosynaptic loop

Answer 3

2

Question 4

What neuron suppresses contraction of antagonist muscles?

Answer 4

1a inhibitory interneuron

Question 5

What happens when we want to co-contract muscles, e.g. to catch a ball?

Answer 5

Requires higher information from brain

Question 6

What is Klippel-Feil syndrome?

Answer 6

Bifurcation of pre-motor neurons leading to mirror movement in the other side of the body

Question 7

What is hyperreflexia and what causes it?

Answer 7

Unregulated gain from a reflex
Injury and stroke

Question 8

Name a treatment for hyperreflexia.

Answer 8

Intrathecal baclofen

Question 9

Describe a flexion withdrawal response

Answer 9

Painful stimulus
Type 3 fibre
Flexion of ipsilateral
Extension of contralateral

Question 10

Describe the swing phase of walking? What muscles are involved and what are there action?

Answer 10

Flexion - hip flexors, tibialis anterior, hamstrings
Concentric contraction for acceleration

Question 11

Describe the stance phase of walking? What muscles are involved and what are their action?

Answer 11

Extension - glutes, triceps surae, quads
Eccentric contraction for deceleration

Question 12

What muscle is controlled by a large area of the brain in walking?

Answer 12

Tibialis anterior

Question 13

What condition prevents dorsi-flexion? And what treatment can be provided?

Answer 13

Foot drop/dorsiflexor paralysis
Switch on the heal - heal lifted = stimulates muscle to contract

Question 14

What is the preferred method of running and what is its benefits?

Answer 14

Fore-foot
Produces less transient force, therefore less shock and injury

Question 15

What formation initiates locomotion?

Answer 15

MLR in the brainstem

Question 16

Can the spine initiate locomotion?

Answer 16

Yes, independent from higher or sensory input
Via central pattern generators

Question 17

Why does it take humans longer to run a bend than a dog?

Answer 17

Propulsion muscles and extensor muscles coupled

Question 18

Why do the eyes move?

Answer 18

To accommodate image onto fovea

Question 19

Name the fast eye movement

Answer 19

Saccades - reset the eyes

Question 20

Name the 4 different types of slow eye movement

Answer 20

VOR
OKR
Smooth pursuit
Vergence

Question 21

Why is it hard to differentiate between VOR and OKR? How can we test them independently of each other?

Answer 21

Both stabilise image onto fovea
VOR in the dark

Question 22

What is a nystagmus?

Answer 22

Alternating fast and slow eye movement

Question 23

Do saccades find image of interest first time?

Answer 23

No - undershoots, then requires corrective saccade

Question 24

How many neurons for the VOR?

Answer 24

3

Question 25

What happens if the vestibular signal decays whilst rotating?

Answer 25

Eye gaze prolonged by the velocity storage mechanism
Once VOR fails, OKR takes over

Question 26

What happens in smoot pursuit?

Answer 26

Tracking of object
Eye predicts movement after object stops moving