Descending tracts

Question 1

Where in the brain do the pyramidal tracts originate?

Answer 1

Cerebral cortex

Question 2

Are the pyramidal or extra pyramidal tracts responsible for voluntary control of movement?

Answer 2

Pyramidal

Question 3

Where in the brain do the extrapyramidal tracts originate?

Answer 3

Brain stem

Question 4

Are the pyramidal or extra pyramidal tracts responsible for involuntary control of musculature such as muscle tone, balance, posture and locomotion.

Answer 4

Extrapyramidal

Question 5

Are there synapses in the descending pathways?

Answer 5

No. At the termination of the descending tracts the neurones synapse with a lower motor neurone.

Question 6

What two structures does the internal capsule run between? Is it made of white or grey matter?

Answer 6

White matter pathway.

Located between the thalamus and the basal ganglia

Question 7

What happens to the fibres of the lateral corticospinal tract when they get to the medulla?

Answer 7

The decussate and then descend into the spinal cord.

Question 8

What pathway controls fine precise movement of the distal lib muscles ( eg fingers)

Answer 8

Corticospinal tracts

Question 9

Is it the fibres of the lateral or anterior corticospinal tracts which cross at the pyramids of the medulla?

Answer 9

Lateral. The anterior corticospinal tract remains ipsilateral until the ventral horn of the spinal cord.

Question 10

What horn of the spinal cord do upper motor neurones synapse with the lower motor neurones?

Answer 10

Ventral

Question 11

If there is damage to the corticospinal tract will the paralysis be of the contralateral or ipsilateral side?

Answer 11

Contralateral

Question 12

Is it the fibres of the lateral or anterior corticospinal tracts which cross at the ventral horn of the spinal cord?

Answer 12

Anterior. The lateral fibres have already crossed at the medulla.

Question 13

What is a capsular stroke. Why is this relevant to the motor pathways?

Answer 13

When the internal capsule is damaged from compression by a haemorrhagic bleed. These could cause a lesion of the descending tracts as the upper motor neurones travel through the internal capsule.

Question 14

What parts of the body does the corticobulbar tracts supply?

Answer 14

Musculature of the head and neck.

Question 15

Describe the route taken in the corticobulbar tracts?

Answer 15

1. Arise from the primary motor cortex
2. The fibres converge and pass through the internal capsule to the brainstem.
3. The neurones then terminate of the motor nuclei of the cranial nerves.
4. Cranial nerves then carry motor signals to the face and neck.

Question 16

What are the four extrapyramidal tracts?

Answer 16

1. Vestibulospinal
2. Reticulospinal
3. Tectospinal
4. Rubrospina;

Question 17

Where do the extrapyramidal tracts arise from?

Answer 17

The brain stem

Question 18

Where does the vestibulospinal tract start?

Answer 18

Vestibular nuclei in the medulla.

Question 19

What is the function of the vestibulospinal tract?

Answer 19

To control balance and posture (Innervates anti gravity muscles - flexors of the arm, extensors of the leg)

Question 20

Do the fibres of the vestibulospinal tract remain ipsilateral or cross to become contralateral?

Answer 20

Remain ipsilateral

Question 21

Where does the medial reticulospinal tract originate and what does it do?

Answer 21

Pons.

Facilitates voluntary movements and increases muscle tone

Question 22

What does the lateral reticulospinal tract do and where does it originate?

Answer 22

Medulla.

Inhibits voluntary movements and reduces muscle tone.

Question 23

Where does the rubrospinal tracr originate?

Answer 23

The red nucleus in the midbrain.

Question 24

What does the tectospinal tract do?

Answer 24

Coordinates movements of the head in relation to visual stimuli.

Question 25

List the 5 cardinal signs of an upper motor neurone lesion

Answer 25

1. Hypertonia
2. Hyperreflexia
3. Clonus
4. Babinski sign
5. Muscle weakness

Question 26

What are the symptoms of damage to the extra pyramidal tracts?

Answer 26

Dyskinesis

Rigidity

Question 27

Do 1st generation anti psychotics result in pyramidal or extra pyramidal side effects?

Answer 27

Extra pyramidal

Question 28

What symptom would you get if there was a lesion of the upper motor neurones for the right hypoglossal nerve?

Answer 28

Deviation of the tongue to the left

Question 29

If there is in infarction of the internal capsule what will patients have?

Answer 29

Spastic paralysis of the upper limbs