Lecture 5- motor control (Direct and indirect activation pathways;U

Question 1

What are the 3 stages of motor learning?

Answer 1

planning, programming, and execution

Question 2

The corticobulbar tract is _______, whereas the corticospinal tract is ______.

Answer 2

Bilaterally; mostly contralateral

Question 3

What is the pathway of the corticospinal tract?

Answer 3

Motor cortex –> UMN synapses with LMN; LMN sends signals down the spinal cord via spinal nerves —-> spinal nerves innervate the skeletal muscles

Question 4

Where in the brain are the UMNs located?

Answer 4

in the motor cortex

Question 5

Where in the brain are the LMNs located?

Answer 5

in the CNS

Question 6

LMN axons leave the CNS through _______.

Answer 6

spinal nerves

Question 7

The left ventral motor area is also known as

Answer 7

Broca’s area

Question 8

The lateral corticospinal tract innervates ____

Answer 8

muscles in the limbs

Question 9

The anterior corticospinal tract innervates _____

Answer 9

muscles of the trunk

Question 10

In the lateral corticospinal tract, where do the UMN axons decussate?

Answer 10

at the caudal medulla or pyramids of the medulla

Question 11

What areas of the brain does the motor impulses go through on the lateral corticospinal tract to innervate a muscle?

Answer 11

motor strip —- > UMN —> internal capsule—-> midbrain —-> pons —-> rostral medualla —- caudal medulla —-> LMN —– spinal cord

Question 12

What is the purpose of the corticospinal tract?

Answer 12

it carries motor impulses from the pre-central gyrus to the skeletal muscles

Question 13

What is the pathway of the anterior corticospinal tract that the motor impulses pass through?

Answer 13

motor strip –> UMN –> internal capsule —> midbrain –> pons –> rostral medulla –> LMN—> spinal cord

Question 14

UMNs in the corticobulbar tract end in the ______

Answer 14

brainstem

Question 15

What are the four indirect pathways of the motor cortex?

Answer 15

rubrospinal, reticulospinal, vestibulospinal, and tectospinal

Question 16

What are general symptoms of lesions to the indirect pathway?

Answer 16

postural imbalance, increased stretch reflex, spasticity, hypertonus

Question 17

What are general symptoms of lesions to the direct pathway?

Answer 17

loss of skilled movement, impaired deep tendon reflexes, Hypotonia, babinski sign

Question 18

How is the corticobulbar tract affected when someone has a large right MCA stroke?

Answer 18

left side of head, face, and neck are weak, issues with CN VII and XII, dysarthria, swallowology issues, and visuospatial issues

Question 19

How is the corticospinal tract affected when someone has a large right MCA stroke?

Answer 19

hemiplegia on the left side (left side of the limbs and trunk are paralyzed)

Question 20

How is the corticobulbar tract affected when someone has a small left hemisphere stroke that affects left MCA anterior ventral distribution?

Answer 20

apraxia, nonfluent aphasia, another motor speech disorder, and some weakness to CN VII and XII

Question 21

How is the corticospinal tract affected when someone has a small left hemisphere stroke that affects left MCA anterior ventral distribution?

Answer 21

weakness on the right side of the body (limbs and trunk)

Question 22

Indirect pathways affects which neurons?

Answer 22

gamma LMNs

Question 23

Direct pathways affect which neurons?

Answer 23

alpha LMNs

Question 24

LMNs are not affected by these brain regions involved in movement

Answer 24

cerebellum and basal ganglia

Question 25

Damage to what tract of the indirect pathway of the motor cortex causes spasticity?

Answer 25

left lateral medullary reticulospinal tract

Question 26

Which two tracts of the indirect pathways do not receive information from the motor cortex?

Answer 26

tectospinal and vestibulospinal

Question 27

Where does the tectospinal tract get information from?

Answer 27

visual and auditory systems

Question 28

Where does the vestibulospinal tract get information from?

Answer 28

vestibular nuclei

Question 29

Where does the rubrospinal tract start?

Answer 29

in the red nucleus of the midbrain

Question 30

Rubrospinal tract gets information from the

Answer 30

cerebellum (part of the motor circuitry

Question 31

Where does the vestibulospinal tract start? What is it responsible for?

Answer 31

the vestibular nuclei in the brainstem; innervates head and neck

Question 32

Which of the tracts of the indirect pathway are bilateral and excitatory?

Answer 32

reticulospinal tract- pontine

Question 33

Which of the tracts of the indirect pathways are bilateral and inhibitory?

Answer 33

reticulospinal tract- medullary

Question 34

What is the function of the reticulospinal tract-pontine?

Answer 34

voluntary movements

Question 35

What is the function of the reticulospinal-tract medullary?

Answer 35

reflex arcs

Question 36

Decorticate posture is a result of damage to ______

Answer 36

corticoreticular tract

Question 37

Corticobulbar tract has _____ and _____ pathways

Answer 37

direct and indirect

Question 38

Where do the corticobulbar tracts start?

Answer 38

the ventral portion of the SMA, PMA, and PMC

Question 39

Corticobulbar tract is also known as the _______

Answer 39

corticonuclear tract

Question 40

What does the primary motor cortex (B.A. 4) do?

Answer 40

innervates spinal and cranial nerves 5,7, 9-12

Question 41

What does the dorsal pre-motor area (B.A. 6) do?

Answer 41

does not affect speech; however, it's responsible for visuomotor coordination, sensorimotor integration

Question 42

What does the ventral pre-motor area (B.A. 6) do?

Answer 42

speech planning and perception; mirror neurons for motor