Lecture 09 - Motor Cortex

Question 1

Motor Cortex

Answer 1

Association motor cortex creates motor plan
-parietal association cortex, BG, cerebellum help

primary motor cortex executes plan via corticospinal and corticobulbar tract

frontal eye fields do horizontal gaze somehow

Question 2

Association motor cortex

Answer 2

supplementary motor cortex (SMA)
Premotor cortex (PMA)

Question 3

Frontal eye field

Answer 3

always lateral frontal cortex, but varied from individual to individual

Question 4

The motor plan

Answer 4

Which muscles, sequence, intensity, duration

• Association motor cortices send motor plan to primary motor cortex for execution
• need parietal association cortex for sensation and vision

Question 5

praxis

Answer 5

ability to do learned purposeful movements

motor plan

Question 6

Corticobulbar tracts

Answer 6

to face/neck
Lateral primary –> corona radiata –> genu of internal capsule –> bilateral to most cranial nerve nuclei with LMN, but variable

speech and swallow need both sides
lower face (CONTRA) and eyes are exceptions

Question 7

Corticospinal tracts

Answer 7

everywhere except face/neck
Primary –> corona radiata –> post. limb of internal capsule –> cerebral peduncle of midbrain –> basis pontis –> medullary pyramind –> pyramidal decussation –> lateral corticospinal tract

Question 8

Apraxia

Answer 8

Inability to perform learned purposeful movements, despite having necessary motivation and basic motor and sensory functions

• deficit in motor planning, doesn’t always involve weakness
• association motor and/or parietal association cortices

Question 9

Paresis

Answer 9

weakness
hemi - unilateral
para - bilateral 
quadri - all four limbs 
di - all four limbs that is worse in legs than arms 
mono - one limb
opthalmo - any eye movement 
gaze - both eyes

Question 10

plegia/paralysis

Answer 10

absence of volitional movement

Question 11

palsy

Answer 11

paresis OR plegia