Cortical control of movement

Question 1

On this LC there is a link to a good website for brain images to aid revision

Answer 1

Its like the 3rd slide/ at 4:35 on the recorded LC.

Question 2

Is the Fasciculi gracilis and cuneatus medial lemniscus pathway an ascending or descending pathway?

And what is it’s function?

Answer 2

• Ascending

- Sensation; Discriminative touch, vibratory sense, conscious muscle joint sense.

Question 3

Is the Anterior and posterior spinocerebellar pathway an ascending or descending pathway?

And what is it’s function?

Answer 3

• Ascending

- Sensation; Unconscious muscle joint sense.

Question 4

Is the Corticospinal pathway an ascending or descending pathway?

And what is it’s function?

Answer 4

• Descending

- Rapid, skilled, voluntary movements (distal ends of limbs)

Question 5

Is the Reticuluospinal pathway an ascending or descending pathway?

And what is it’s function?

Answer 5

• Descending

- Inhibit/facilitate voluntary movements.

Question 6

Is the Rubrospinal pathway an ascending or descending pathway?

And what is it’s function?

Answer 6

• Descending

- Facilitates activity flexor muscles, inhibits extensors.

Question 7

Is the Tectospinal pathway an ascending or descending pathway?

And what is it’s function?

Answer 7

• Descending

- Sight-postural reflexes

Question 8

Is the Vestibulospinal pathway an ascending or descending pathway?

And what is it’s function?

Answer 8

• Descending

- Facilitates activity of extensor muscles, inhibits flexors.

Question 9

The Cortex is split into 3 parts what are those 3 parts called?

Answer 9

• Primary motor cortex (Broadman 4)
• Premotor areas (Broadman 6,8)
• Supplementary motor area

Question 10

What is the function of the Primary cortex?

Answer 10

Made up of; Premotor, supplementary and somatosensory cortices.

Active during; Movement

Question 11

What is the function of the Premotor cortex?

Answer 11

Made up of; Prefrontal and Parietal cortices.

Active during; Preparation to move, voluntary response to external cues.

Question 12

What is the function of the Supplementary cortex?

Answer 12

Made up of; Prefrontal cortices.

Active during; planning and execution of planned motor sequences.

Question 13

What are the 6 layers of the human Cortex?

Answer 13

1. Molecular layer
2. External granular layer
3. External pyramidal layer
4. Internal granular layer
5. Ganglionic layer
6. Multiform layer

Question 14

What are the symptoms of a primary motor cortex lesion (Area 4)?

Answer 14

Origin of corticospinal and corticoconuclear tracts (pyramidal tracts).

Symptoms

• Babinski sign (Stim on sole of the foot, great toe dorsi flexed other toes outward)
• no superficial abdominal reflexes
• no cremasteric reflexes
• problems with fine and skilled movements.

Question 15

What are the symptoms of a Premotor cortex lesion (Area 6)?

Answer 15

Origin of extrapyramidal tracts - basal ganglia and reticular formation (no corticospinal)

Symptoms;

• Severe paralysis
• Spasticity/hypertonicity
• Higher deep muscles reflexes.
• Clasp-knife reaction.
• Muscle spasm.

Question 16

What are the symptoms of a Supplemental motor cortex lesion?

Answer 16

• Speech arrest
• Contralateral weakness
• SMA syndrome (muteness and akinesia)