Locomotion and posture

Question 1

What is meant by having a secure synapse?

Answer 1

Only one signal is required to active the post synaptic cell

Question 1

What is the pattern of loss of innervation in UMN lesions of the face?

Answer 1

Loss of innervation to the bottom quadrant on the contralateral side

Question 1

What is the difference between UM and LM lesion signs?

Answer 1

UMNL

Spastic weakness

Increased tone

Increased reflexes

Babinski sign positive

LMN

Flaccid weakness

Atropy

Decreased tone

Decreased reflexes

Negative babinski sign

Signs of deinnervation - fasciculations and fibrillations

Question 2

Most of the input from the brain to local spinal cord motor neurons is via what?

Answer 2

Local interneurons

Question 4

What is scanning speech due to?

Answer 4

Problems in the cerebellum

Question 4

What are fasciculations?

Answer 4

Groups of muscles fibres activating spontaneously, probably due to signs for dying MNs/axons

Question 5

Which tract has direct connections from the cortex to local motor neurons in the spinal cord?

Answer 5

The lateral corticospinal tract

Question 6

What are some signs of faulty motor control?

Answer 6

• paralysis weakness
• stiffness
• increased reactivity
• ticks, twitches and jerks
• fibrillation and fasciculations
• loss of coordination and smoothness
• loss of the effectiveness of movements.
• speech problems.

Question 7

What is Henneman’s size principle?

Answer 7

In the recruitment of motor units for a movement, the smallest, least fatigable are recruited first while the biggest are recruited last

Question 8

What is expressive aphasia?

Answer 8

Inability to formulate words despite being able to comprehend them, due to disconnection between the language and motor areas required for speech

Question 9

The colliculospinal tract is for what?

Answer 9

Orientating reflexes

Visual looming - eg falling

Question 9

Why are there different patterns of innervation loss between upper and lower motor neuron injuries of the facial nerve?

Answer 9

Because the upper half of the face receives innervation from both sides of the face

Question 10

T/F Lateral motor tracts control more lateral motor neurons

Answer 10

True

Question 12

In which part of muscular control do you find very secure synapses?

Answer 12

Peripheral muscle synapses

Question 13

What is the receptor at the neuromuscular cleft?

Answer 13

Nicotinic receptor

Question 14

Motor control from the lateral vestibular nuclei is important for what?

Answer 14

Maintenance of posture

Question 15

When does the motor cortex come into locomotor?

Answer 15

Initiating locomotion

Modulating pattern generation in response to obstacles

Question 16

What controls the initiation of swing in locomotion?

Answer 16

Feedback from receptors in extensor muscles

eg extension is still maintained while there is feedback from golgi tendon organs that a load is present

Question 18

What is the purpose of post junctional folds at the neuromusclar cleft?

Answer 18

Increase the SA for ACh and nicotinic receptors

Question 19

What is anticipation?

Answer 19

Learned movement that compensates for reflexes

eg When catching a ball, the muscle involved will contract in preparation and help with the reflexes to together control movement required for catching

Question 20

What are UMNs?

Answer 20

Neuronal systems that influence the lower motor neuron

Question 22

What are signs of de-activation of muscle?

Answer 22

Fibrillations

Fasciculations

Atropy and degeneration

Question 22

What are fibrillations?

Answer 22

Tiny contraction of sinlge muscle fibres due to hyperreactivity or increased AChr expression

Question 23

Gait abnormalities are good clinical signs because?

Answer 23

They correspond to specific CNS disorders

Question 24

What does a change from decorticate to decerebrate sign tell you?

Answer 24

The lesion is spreading downwards towards to the reticular formation

Question 25

What is the difference between decorticate and decerebrate signs?

Answer 25

In decerebrate the lesion has spread down to disrupt the rubrospinal tract of the red nucleus (that causes flexion) therefore you get extension of both limbs

Question 26

Why do babies exhibit positive Babinski sign before they’ve learnt to walk?

Answer 26

The brain is yet to exert influence on the spinal cord

Question 27

What does a decerebrate sign looks like?

Answer 27

Upper and lower limbs extended

Question 28

What does a decorticate sign look like?

Answer 28

Extension of lower limb and flexion of upper limb

Question 30

Where are the locomotion pattern generators?

Answer 30

In the spinal cord

Question 31

As a rule, the ventromedial tracts are for much?

Answer 31

Control of posture

Question 32

What is an example of preparatory control of postural stability?

Answer 32

Activation of hip and shoulder on the contralateral side of a abducting leg to compensate for increased weight

Question 33

What is the pattern of loss of innervation in LMN lesions of the face?

Answer 33

Loss of innervation of the whole ipsilateral side of the face

Question 34

What is the neurotransmitter at the neuron muscular cleft?

Answer 34

ACh

Question 35

What does scanning speech sound like?

Answer 35

Slow, forceful, lacks intonation

Question 36

The lateral corticospinal tract is for what type of movement?

Answer 36

It innervates lateral muscles - therefore mainly voluntary skilled movement