Organization of Motor System

Question 1

Only animals that ___ need brains

Answer 1

Move

Question 2

which phenomenon demonstrates the hierarchical organization of the brain?

Answer 2

motor equivalence

Question 3

motor equivalence is

Answer 3

achieving the same output regardless of what effectors are used. EX the idiosyncrasies of your signature remain regardless of what you use to write it

Question 4

elementary units serve what function?

Answer 4

muscle activation (low in the hierarchy)

Question 5

all muscles are in this arrangement around joints

Answer 5

antagonist pairs

Question 6

large spinal cord neurons that activate muscles fibers are known as

Answer 6

alpha neurons

Question 7

to increase the amount of force you must increase…

Answer 7

the number of active motor units (alpha neurons plus their fibers, which fire in an all or none fashion)

Question 8

stretching of muscle is sensed by

Answer 8

muscles spindles

Question 9

muscle spindles synapse onto

Answer 9

alpha neurons AND inhibitory interneurons to inhibit opposite muscles

Question 10

primary motor cortex is broddmann’s area

Answer 10

4

Question 11

which has a higher density of descending fibers, primary motor cortex or SMA/PMC?

Answer 11

primary motor cortex

Question 12

the M1 motor homunculus is organized according to

Answer 12

action patterns (rather than anatomy, like SS homunculus)

Question 13

population vectors can be best described as

Answer 13

a summation of directionally tuned neurons firing (vector sum) q

Question 14

population vectors form ___ movement execution

Answer 14

before

Question 15

what are the complications of BMI

Answer 15

neural activity is not simple to translate into actions: direction is encoded, but also durations and velocity, neurons are multifunctional and strongly intertwined with sensory feedback