Motor Control

Question 1

What are the two types of major descending tracts?

Answer 1

-Pyramidal tracts
-Extra pyramidal tracts

Question 2

What do the pyramidal tracts pass through?

Answer 2

The pyramids of the medulla

Question 3

What are the two main pyramidal tracts.

Answer 3

-Corticospinal
-Corticobulbar

Question 4

What are the pyramidal tracts involved in.

Answer 4

Voluntary movements of the body and face.

Question 5

What are the 4 main extra pyramidal tracts.

Answer 5

-Vestibulospinal
-Tectospinal
-Reticulospinal
-Rubrospinal

Question 6

What are the extra pyramidal tracts involved in.

Answer 6

involuntary (automatic) movements for balance, posture and locomotion

Question 7

Which tracts do not pass through the pyramids of the medulla.

Answer 7

Extra pyramidal tracts:
-Vestibulospinal
-Tectospinal
-Reticulospinal
-Rubrospinal

Question 8

What is the vestibulospinal tracts involved in.

Answer 8

To maintain head and eye coordination, upright posture and balance.

Question 9

What is the tectospinal tracts involved in. + origin

Answer 9

From superior colliculus of midbrain.
Orientation of the head and neck during eye movements

Question 10

What is the reticulospinal tracts involved in and where does it originate from?

Answer 10

• Most primitive descending tract- from medulla and pons
• Changes in muscle tone associated with voluntary movements
• postural stability

Question 11

What is the rubrospinal tracts involved in and where does it originate from?

Answer 11

• From red nucleus of midbrain
• In humans mainly taken over by corticospinal tract
• Innervate lower motor neurones of flexors of upper limb

Question 12

Where is the primary motor cortex located.

Answer 12

In the precentral gyrus, anterior to the central sulcus.

Question 13

Where is the premotor area located.

Answer 13

Anterior to the primary motor cortex.

Question 14

Where is the supplementary motor area located.

Answer 14

Located anterior and medial to primary motor cortex.

Question 15

Where does the corticospinal tract decussate.

Answer 15

In the medulla.

Question 16

What muscle groups does the lateral corticospinal tract innervate.

Answer 16

Limb muscles

Question 17

What muscles groups does the anterior corticospinal tract innervate.

Answer 17

Trunk muscles.

Question 18

What are three negative signs of an upper motor neuron lesion.

Answer 18

-Loss of voluntary motor function
-Paresis: graded weakness of movements
-Paralysis (plegia): complete loss of voluntary muscle activity

Question 19

What are three positive signs of an upper motor neuron lesion.

Answer 19

-Increased abnormal motor function due to loss of inhibitory descending inputs
-Spasticity: increased muscle tone
-Hyper-reflexia: exaggerated reflexes
-Clonus: abnormal oscillatory muscle contraction
-Babinski’s sign

Question 20

how is apraxia best described?

Answer 20

A disorder of skilled movement.

Question 21

What are the two most common causes of apraxia.

Answer 21

STROKE & DEMENTIA

Question 22

Symptoms of a lower motor neuron lesion.

Answer 22

-Weakness
-Hypotonia (reduced muscle tone)
-Hyporeflexia (reduced reflexes)
-Muscle atrophy
-Fasciculations: damaged motor units produce spontaneous action potentials, resulting in a visible twitch
-Fibrillations: spontaneous twitching of individual muscle fibres; recorded during needle electromyography examination

Question 23

Motor neuron disease is best described as.

Answer 23

A progressive neurodegenerative disorder of the motor system.

Question 24

What is motor neuron disease also known as?

Answer 24

Amyotrophic Lateral Sclerosis (ALS)

Question 25

What is Babinski's sign

Answer 25

Reversed plantar reflex, (extension of toes rather than curling downwards after sole of foot is stimulated).

Question 26

What is Babinski's sign indicative of.

Answer 26

Upper motor neuron disease/ lesion.

Question 27

What is parkinsons?

Answer 27

Degeneration of the dopaminergic neurones that originate in the substantia nigra and project to the striatum

Question 28

What are the symptoms of parkinsons?

Answer 28

- Bradykinesia- Slowness of small movements (doing up buttons, handling a knife) - Akinesia- Difficulty in initiation of movements because can't initiate movements internally - Hypomimic face- Expressionless, mask-like (absence of movements that normally animate the face) - Rigidity- Muscle tone increase, causing resistance to externally imposed joint movements - Pill rolling tremor

Question 29

What is huntington's

Answer 29

Degeneration of inhibitory GABAergic neurones in the striatum → caudate and then putamen

Question 30

Describe the aetiology, (inheritance pattern) of huntingtons

Answer 30

It's genetic- autosomal dominant, chromosome 4 has a CAG repeat

Question 31

What are the symptoms of huntington's

Answer 31

- Choreic movements (chorea is dance)- rapid jerky involuntary movements of body - Hands and face affected first - Then legs - Then rest of body - Speech impairment - Dysphagia - Unsteady gait - Later stages has cognitive decline and dementia

Question 32

What is ballism?

Answer 32

- usually from stroke affecting subthalamic nucleus - generally one sided and causes uncontrolled flinging of extremities - Symptoms occur contralaterally

Question 33

What does the vestibulocerebellum do? And what does a lesion in this area do?

Answer 33

- Regulation of gait, posture and equilibrium - Coordination of head movements with eye movements. Damage (tumour) causes syndrome similar to vestibular disease leading to gait ataxia (unsteady, staggering gait) and tendency to fall (even when patient sitting and eyes open)

Question 34

What does the spinocerebellum do? (3)

Answer 34

- Coordination of speech - Coordination of limb movements - Adjustment of muscle tone

Question 35

What does damage to the spinocerebellum do?

Answer 35

Damage (degeneration and atrophy associated with chronic alcoholism) affects mainly legs, causes abnormal gait and stance (wide-based)

Question 36

What does the cerebrocerebellum do? (5)

Answer 36

- Coordination of skilled movements - Cognitive function - Attention - Processing of language - Emotional control

Question 37

What does damage to this section do? (Cerebrocerebellum)

Answer 37

Damage affects mainly arms/skilled coordinated movements (tremor) and speech

Question 38

A person experiencing these symptoms most likely has what? -Ataxia -Dysmetria -Intention tremor -Dysdiadochokinesia -Scanning speech

Answer 38

cerebellar dysfunction

Question 39

What do alpha motor neurones do?

Answer 39

They are the lower motor neurones of the brainstem and spinal cord They innervate the extrafusal muscle fibres of the skeletal muscle and their activation causes muscle contraction

Question 40

What is the motor neuron pool?

Answer 40

Contains all alpha motor neurones innervating a single muscle

Question 41

Where are alpha motor neurones located?

Answer 41

In the anterior horn of grey matter of spinal cord also located in the brainstem

Question 42

What is the Jendrassik manouevre?

Answer 42

If you clench your teeth, make a fist or pull against locked fingers when your patellar tendon is tapped, the reflex becomes larger

Question 43

What is hyperflexia associated with?

Answer 43

UMN lesion, loss of descending inhibition

Question 44

What is clonus?

Answer 44

- A sign of UMN dysfunction - Involuntary and rhythmic muscle contractions - Loss of descending inhibition

Question 45

What is hypoflexia associated with

Answer 45

LMN diseases

Question 46

What is the most common muscle type change after training?

Answer 46

Type IIB (Fast fatigue able) to type IIA (Fast fatigue resistant)

Question 47

When is type I to type II muscle fibre change common?

Answer 47

After severe deconditioning or spinal cord injury.

Question 48

What kind of muscle fiber changes is associated with aging?

Answer 48

loss of type I and II fibres but also preferential loss of type II fibres.

Question 49

What are the two mechanisms by which the brain regulates the amount of force a single muscle can produce?

Answer 49

-Recruitment -Rate coding

Question 50

What is the factor called that prevents neuronal death and promotes growth of neurons after injury?

Answer 50

Neurotrophic factors

Question 51

What are fasiculations and what kind of motor neurone disease do you get them in?

Answer 51

Tiny muscle twitches, you get them in lower motor neurone disease