Motor Control

Question 1

hierarchical organisation (motor control)

Answer 1

higher order > more complex tasks e.g. programme/decide movement, coordinate muscle activity
lower order > low level tasks e.g. execution of movement

Question 2

functional segregation (motor control)

Answer 2

motor system organised is a number of different areas for different aspects of movement

Question 3

Draw a flow chart/diagram of the motor system hierarchy.

Answer 3

> = arrows from
motor cortices > cerebellum, basal ganglia, brainstem spinal cord
basal ganglia > thalamus > motor cortices
cerebellum > thalamus, brainstem
thalamus > motor cortices
brainstem > spinal cord, muscles of face, head, neck
spinal > muscles of body

Question 4

The major descending tracts can be grouped into?

Answer 4

Pyramidal

Extrapyramidal

Question 5

List examples of pyramidal tracts.

Answer 5

corticospinal

corticobulbar

Question 6

List examples of extrapyramidal tracts.

Answer 6

vestibulospinal
tectospinal
reticulospinal
rubrospinal

Question 7

Pyramidal tracts run from where to where?

Answer 7

motor cortex to spinal cord or cranial nerve nuclei in brainstem

Question 8

Pyramidal tracts control what type of movements?

Answer 8

voluntary movements of body and face

Question 9

Extrapyramidal tracts control what type of movements?

Answer 9

involuntary movements for balance, posture, locomotion

Question 10

Where is the primary motor cortex located?

Answer 10

precentral gyrus, anterior to central sulcus

Question 11

Primary motor cortex controls?

Answer 11

fine discrete precise voluntary movements

Question 12

Where is the premotor area located?

Answer 12

anterior to primary motor cortex

Question 13

Premotor area is involved in?

Answer 13

planning movements

regulates externally cued movements

Question 14

Where is the supplementary motor area located?

Answer 14

anterior and medial to primary motor cortex

Question 15

The supplementary motor area is involved in?

Answer 15

planning complex movements
becomes active prior to voluntary movement
internally cued movements

Question 16

Describe the path of the corticospinal tract.

Answer 16

upper motor neurons > cerebral peduncle > 85-90% decussation in medullary pyramids > splits into lateral and anterior tracts > lower motor neurons (ant > trunk) (lat > limb)

Question 17

Corticobulbar tracts is the principal motor pathway for?

Answer 17

voluntary movements in the face and neck

Question 18

Functions of the vestibulospinal tracts?

Answer 18

stabilise head, coordinate head with eyes, mediate postural adjustments

Question 19

Function of reticulospinal tract?

Answer 19

from med. to pons, change in muscle tone associated with voluntary movement, postural stability,

Question 20

tectospinal tract runs from?

Answer 20

superior colliculus of midbrain

Question 21

tectospinal tract is involved in?

Answer 21

orientation of head and neck during eye movements

Question 22

Rubrospinal tract runs from?

Answer 22

red nucleus of the midbrain

Question 23

Functions of rubrospinal tract

Answer 23

innervate lower motor neurons of upper limb flexors

Question 24

negative signs of upper motor neuron lesion?

Answer 24

loss of voluntary motor fx
paresis (graded weakness)
paralysis

Question 25

positive signs of upper motor neuron lesion?

Answer 25

^ abnormal motor fx (loss of inhibitory input) spasticity hyper reflexia clonus (abnormal oscillatory muscle contraction) Babinski's sign

Question 26

What is apraxia?

Answer 26

disorder of skilled movement, lost info on how to perform skilled movements

Question 27

Lesions is what regions cause apraxia

Answer 27

inferior parietal lobe | frontal lobe

Question 28

Most common causes of apraxia?

Answer 28

stroke | dementia

Question 29

Lesions of lower motor neurons cause?

Answer 29

weakness, hypotonia, hyporeflexia, muscle atrophy, fibrillation, fasciculations

Question 30

Upper motor neuron signs of MND

Answer 30

spasticity, brisk limbs/jaw reflexes, Babinski sign, loss of dexterity, dysphagia, dysarthria

Question 31

lower motor neuron signs of motor neuron disease

Answer 31

weakness, muscle wasting, nasal speech, dysphagia, tongue fasiciculations / wasting

Question 32

Function of caudate nucleus

Answer 32

decision to move

Question 33

Function of lentiform nucleus

Answer 33

assists the cerebellum in coordinating small, precise muscle movements (with the caudate nucleus forms the striatum which is part of the basal ganglia)

Question 34

what is the basal ganglia?

Answer 34

region of the base of the brain that consists of three clusters of neurons (caudate nucleus, putamen, and globus pallidus) > thalamus, nucleus accumbens, amygdala, anterior commisure

Question 35

Parkinson's disease is the degeneration of (?) neurons that originate from (?) and projects to (?)

Answer 35

dopaminergic substantia nigra striatum

Question 36

Symptoms of parkinson's disease

Answer 36

bradykinesia, hypomimic face, akinesia, rigidity, tremor at rest

Question 37

Huntington's disease is the degeneration of (?) neurons in the (?) (?) (?)

Answer 37

GABAergic striatum caudate putamen

Question 38

What genetic abnormality causes Huntingdon's disease?

Answer 38

autosomal dominant chromosome 4 CAG repeats

Question 39

Symptoms of Huntingdon's

Answer 39

``` choreic movements speech impairment difficulty swallowing unsteady gait cognitive decline dementia ```

Question 40

Ballism is usually from?

Answer 40

stroke affecting subthalamic nucleus

Question 41

Symptoms of ballism

Answer 41

sudden uncontrolled flinging of the extremities, | symptoms occur contralaterally

Question 42

Cerebellum is separated from the cerebrum by?

Answer 42

tentorium cerebelli

Question 43

Motor function of cerebellum

Answer 43

coordinator and predictor of movement

Question 44

Function of vestibulocerebullum?

Answer 44

Regulation of gait, posture and equilibrium | Coordination of head movements with eye movements

Question 45

Tumour of vestibulocerebellum causes what?

Answer 45

syndrome similar to vestibular disease leading to gait ataxia and tendency to fall (even when patient sitting and eyes open)

Question 46

Function of spinocerebellum?

Answer 46

Coordination of speech Adjustment of muscle tone Coordination of limb movements

Question 47

Damage to spinocerebellum done usually by?

Answer 47

degeneration and atrophy associated with chronic alcoholism

Question 48

Damage to spinocerebellum affects what?

Answer 48

affects mainly legs, causes abnormal gait and stance (wide-based)

Question 49

Function of cerebrocerebellum?

Answer 49

Coordination of skilled movements Cognitive function, attention, processing of language Emotional control

Question 50

Damage to cerebrocerebellum mainly affects?

Answer 50

mainly arms/skilled coordinated movements (tremor) and speech

Question 51

What are the main signs of cerebellar dysfunction apparent only on movement?

Answer 51

ataxia (loss of full control of body movements) dysmetria (impaired ability to estimate distance in muscular action) intention tremor (when attempting precise movement) scanning speech (staccato) dysdiadochokinesia (impaired ability to perform rapid, alternating movements)

Question 52

function of basal ganglia

Answer 52

helps control eye movements | role in motivation, decision making and memory