B5 CNS: Anatomy of the Motor Nervous System

Question 1

Name the ventromedial descending tracts

Answer 1

Pontine
Tectal
Vestibular

Question 2

Name the dorsilateral descending tracts

Answer 2

Corticospinal
Rubral/ Rubrospinal
Hypothalamospinal

Question 3

What is the difference between pyramidal and extra pyramidal tracts?

Answer 3

Pyramidal - Corticospinal and corticobulbar

Extra pyramidal - all the other descending tracts

Question 4

Which descending tract innervates the pectoral girdle?

Answer 4

Rubrospinal

Question 5

A patient presents with intention tremors and impaired distal arm and hand movement. Which tract has been affected?

Answer 5

Rubrospinal

Question 6

Which tract is most closely associated with Horner’s syndrome?

Answer 6

Hypothalamospinal

Question 7

What tract is responsible for the sympathetic input to the facial muscles?

Answer 7

Hypothalamospinal

Question 8

What are the symptoms of Horner’s syndrome?

Answer 8

Anhydrosis- Loss of sweat glands
Ptosis- Droopy eyelids
Miosis- Dilated pupil

Question 9

What structure would have to be damaged for you to get a complete descending tract lesion?

Answer 9

Internal capsule

Question 10

What percentage of fibres that go on to supply the trunk in the cortical pathway decussate in the medulla?

Answer 10

85-90%

Question 11

What effect does the pontine tract have on extensor muscles?

Answer 11

Excitates them

Question 12

Where would you find the biggest bundle of commissure fibres in the brain?

Answer 12

Corpus callosum

Question 13

What is the only descending tract to remain ipsilateral?

Answer 13

Pontine

Question 14

Which tracts can project to the dorsal gray and modify sensory information?

Answer 14

Corticospinal

Pontine

Question 15

Where does the tectal spinal tract run?

Answer 15

Superior colliculus -> Cervical spinal cord

Question 16

What tract is responsible for innervating the proximal shoulder girdle and neck?

Answer 16

Tectal

Question 17

What is ballistic reaching?

Answer 17

Moving with your shoulder more than with your hands

Question 18

What input does the vestibular tract get?

Answer 18

Cranial nerve VIII

Question 19

What tract helps keep us upright?

Answer 19

Vestibular

Question 20

A patient is brought in by a friend- they are not able to navigate themselves and they have no sense of balance though they can still use their extremities. Which tract is this most likely to affect?

Answer 20

Vestibular

Question 21

Is the pre-central gyrus sensory or motor in function?

Answer 21

Motor

Question 22

Which lobe is most associated with motor function?

Answer 22

Frontal