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1

Which Brodmann's area is associated with the primary motor cortex?

area 4

2

Neurons from which spinal tracts arise from the primary motor cortex and associated motor cortices?

Corticospinal tract (CST) and corticonucleus system 

3

What type of neurons arise from the motor cortices?

UMNs

4

How is the motor homunculus organized?

5

Where do CST fibers cross?

pyramidal decussation in the medulla 

6

What side of the body is innervated by the L primary & associated motor cortices?

The R side of the body 

7

A lesion in the CST tract rostral/superior to the medulla pyramids results with hemiparesis or hemiplegia on what side of the body?

contralateral side of lesion b/c lesion is before decussation 

8

A lesion of the CST caudal/inferior to the medulla pyramids results in hemiparesis on which side of the body?

ipsilateral side b/c lesion is after decussation 

9

Fibers of the corticonuclear tract project where?

to the motor nuclei of CNs in the midbrain, pons & medulla 

10

What are the only two groups of head/facial muscles to receive contralateral innervations instead of bilateral innervation by UMNs of the Corticonucleus system?

lower facial muscles & genioglossus muscle 

11

The lateral corticospinal tract supplies what type of muscles?

appendicular muscles (muscles of extremities) 

12

The anterior corticospinal tract supplies what type of muscles?

axial muscles (muscles of the trunk) 

13

Which part of the corticospinal tract does not cross to the contralateral side?

The anterior CST

14

After leaving the motor cortices what structures do the UMNs  axons of the CST pass through in the telencephalon?

corona radiata --> posterior limb of internal capsule 

15

What do UMNs of the CST code for/ what is their effect on LMNs?

encode for required force & direction of movement 

16

What brain systems/regions are important for the activation of the appropriate response to a stimulus?

Cerebellum, Basal nuclei, thalamus, and primary/supplemental sensory cortices 

17

What is Brodmann area 6?

supplementary motor cortex 

18

What cortical region plans the muscular movements and what executes the plan 

  • supplementary motor cortex (area 6) = plans 
  • primary motor cortex (area 4) = executes 

19

UMNs from which motor cortex project to the reticular activating system to form the reticulospinal fiber/tract? 

supplementary motor cortex 

20

What structure is located at the anteromedially most part of the striatum 

Nucleus accumbens 

21

What structures lies superomedially to the internal capsule?

caudate nucleus 

22

What structures lie lateral to the internal capsule?

Lentiform nucleus (globus pallidus and putamen) of the basal nucleus 

23

What structure lies directly medial to the putamen?

globus pallidus 

24

What structure lies directly lateral to the globus pallidus?

putamen 

25

What is the function of the putamen?

subconscious muscular movement (i.e. posture) 

26

What is the function of the caudate nucleus?

patterned movements associated w/ walking (remember cycle?)

27

What is the function of the globus pallidus? 

  • adjusts muscle tone
    • (influences UMNs' modulatory effects on LMNs) 

28

What are the 5 major nuclei of the basal nuclei/ganglia?

  1. caudate nucleus 
  2. nucleus accumbens 
  3. globus pallidus 
  4. putamen
  5. substantia nigra

29

What is the most ventral part of the midbrain?

substantia nigra (posterior to cerebellar peduncle but anterior to the tegmentum)

30

What are the 2 parts of the substantia nigra?

pars compacta and pars reticulate