5.4 Central Motor Systems II

Question 1

primary motor cortex also known as _____ or area ______ , located in precentral gyrus, responsible for execution of movement

Answer 1

M1, area 4

Question 2

focal epilepsy, follows homonculus pattern, often begins at fingers and moves more poximal

Answer 2

Jacksonian seizures

Question 3

Motor cortex neurons not only initiate the movement but also encode the amount of muscle _______ produced during the movement, endoced by firing ______

Answer 3

force, rate

Question 4

neurons are tuned to a specific ________ of movement

Answer 4

direction

Question 5

cortex responsible for planning movement before execution, prep for movement (motor set)?

Answer 5

premotor cortex

Question 6

cortex responsible for complex sequences, mental rehearsal, bimanual coordination?

Answer 6

supplementary motor cortex

Question 7

cerebral blood flow is _______ to activity

Answer 7

proportional

Question 8

cortex responsible for extrapersonal space within reach, selective attention to objects of interest?

Answer 8

parietal cortex

Question 9

area 5 in parietal cortex for ______ and area 7 for _____

Answer 9

arm, eye

Question 10

lenticulostriate arteries feed _______ and _______

Answer 10

basal ganglia, internal capsule

Question 11

most common lesion to motor cortex?

Answer 11

capsular, damage due to cerebellar/basal ganglic/thalamic

Question 12

similar to capsular infarct but injury less severe, more focal injury

Answer 12

M1 lesion

Question 13

impairment in coordination and rapid movements, can’t perform externally cued motor movements

Answer 13

PM lesion

Question 14

speech difficulty, alien hand syndrome

Answer 14

SMA lesion

Question 15

1. Neglect of the contralateral arm and neglect of objects in the contralateral visual field. These deficits are most common with lesions of the right (non-dominant) hemisphere. Remember that parietal cortex contains neurons that issue commands for eye and hand movements to contralateral extrapersonal space. Patients with unilateral parietal lesions treat the contralateral limbs as useless appendages and ignore the contralateral side of the body.
2. Apraxia: difficulty manipulating objects with the contralateral hand.
3. Astereognosis: failure to recognize objects placed in the contralateral hand.
4. Errors in the accuracy of arm movements.
5. Difficulty performing discrete finger and hand movements requiring visual or proprioceptive cues.
   Bilateral lesions produce deficits that are bilateral and more severe.

Answer 15

parietal lesion