6 - Motor system 2 Flashcards Preview

Semester 5 - Neuro > 6 - Motor system 2 > Flashcards

Flashcards in 6 - Motor system 2 Deck (23):
1

What part of the internal capsule contains the corticobulbar tracts?

Genu of internal capsule

2

What area of the internal capsule contains the motor fibres to the head and neck?

Genu of internal capsule

3

Name the pyramidal fibres which supply the head and neck:

Corticobulbar tracts

4

Where do the corticobulbar tracts terminate?

Cranial nerve nuclei in the brainstem

5

Describe the course of the corticobulbar tract:

- Fibres originate from cerebral cortex
- Through corona radiata
- Through genu of internal capsule
- Terminate on both left and right CN nuclei in brainstem (except CN VII, XII)

6

Name the pyramidal fibres which supply the body:

Corticospinal tracts

7

Which areas of the cerebral cortex do the pyramidal tracts arise from?

- Motor cortex (pre-central gyrus)
- Premotor cortex
- Supplementary motor area
- Somatosensory cortex

8

The internal capsule is closely associated with which major artery?

Middle cerebral artery

9

What is the blood supply to the internal capsule?

Lenticulostriate arteries

10

Describe the route of the lateral corticospinal tracts:

- Fibres originate from cerebral cortex
- Through corona radiata
- Through posterior limb of the internal capsule
- Through crus cerebri of cerebral peduncles in midbrain
- Decussate just below pyramids of medulla
- Descend contralaterally in lateral white matter of spinal cord

11

What is the role of the lateral corticospinal tracts?

Voluntary control of the muscles of the limbs

12

What is the blood supply to the corticospinal tracts in the spinal cord?

Anterior spinal artery

13

Describe the route of the anterior corticospinal tracts:

- Fibres originate from cerebral cortex
- Through corona radiata
- Through posterior limb of the internal capsule
- Through crus cerebri of cerebral peduncles in midbrain
- Descend ipsilaterally in anterior white matter of spinal cord
- Decussate at exit level of spinal cord

14

What is the role of the anterior corticospinal tracts?

Voluntary control of the muscles of the trunk

15

Explain forehead sparing in stroke:

- Stroke is usually a lesion in one hemisphere
- Facial nerve nuclei supplying the upper half of the face receive innervation from both hemispheres
- Therefore can still control all muscles of forehead, even though unilateral UMN lesion

16

What is a quick examination to distinguish between stroke and Bell's palsy?

Ask patient to raise eyebrows
- If can = stroke (forehead sparing)
- If cannot unilaterally = bell's palsy

17

Is the net effect of extrapyramidal tracts on LMN's excitatory or inhibitory?

Inhibitory

18

Which descending tracts control voluntary movement?

Pyramidal tracts:
- Corticobulbar
- Corticospinal

19

Which descending tracts control automatic involuntary movement?

Extrapyramidal tracts:
- Tectospinal
- Rubrospinal
- Vestibulospinal
- Reticulospinal

20

Give some signs of pyramidal tract lesions:

- Rigidity
- Spastic paresis
- Positive Babinski sign
- Absent facial movement
- Hyperreflexia

21

Give some signs of extrapyramidal lesions:

- Pin-rolling tremor
- Festinating gait
- Paucity of facial movement
- Cog-wheel rigidity
- Intention tremor
- Dysdiadochokinesia

22

Give some signs of LMNs:

- Muscle weakness
- Wasting
- Fasciculations
- Hyporeflexia
- Hyperreflexia

23

Name some causes of chorea:

- Huntington's disease
- Syndenham's chorea
- Wilson's disease
- SLE
- Thyrotoxicosis
- Levodopa