motor function

Question 1

motor function is what horn?

Answer 1

ventral horn

Question 2

whats more in a pool: neurons or muscle fibres

Answer 2

more muscle fibres
(each muscle to 1 neuron, but 1 neuron to many fibres)

Question 3

what NT & receptors does NMJ use?

Answer 3

Ach via nicotinic receptors

Question 4

conduction of intrafusal vs extrafusal fibres

Answer 4

extra: fast
intra: slower?

Question 5

group I and II afferent axons
(what do they tell us and what adaptation?)

Answer 5

tell us about strength & length
slow adapting

Question 6

muscle spindles detect what info?

Answer 6

stretch (via length)

Question 7

golgi tendon organs detect what?

Answer 7

force

Question 8

role of extensor muscle in reflex

Answer 8

push harder to keep you upright
(make sure you dont fall over)

Question 9

flexion vs extension

Answer 9

f: short
e: extend

alternate during gate

Question 10

lateral and medial vestibulospinal tracts

Answer 10

sense movement for balance (L)
balance control

Question 11

reticulospinal tract

Answer 11

change brain state to prepare s.c for action

Question 12

colliculospinal tract

Answer 12

integrates sensory info into 3D map
neurons sense world getting bigger / smaller when moving = position shifting

Question 13

feed forward

Answer 13

prepare body for action
exp: when tone sounds pull bar, 1st calf contracts to increase stability

Question 14

primary motor cortex function vs premotor cortex

Answer 14

pre: harder to generate movements b/c more purposeful
pms: brisk, rapid movement (not compound) w short latency

Question 15

motor pathway

Answer 15

s.c. - medulla - pons - midbrain - cortex

Question 16

stimulation of PMC does what?

Answer 16

encodes where you want muscles to go

Question 17

upper motor neuron syndrome

Answer 17

relfex = stronger (less inhib from brain = more reflex)
muscles can move but not perform tasks
large spontaneous twitches

Question 18

lower motor neuron syndrome

Answer 18

weakness / paralysis
tendon reflex doesnt work
muscle without nerve cant be regenerated

Question 19

basal ganglia main function

Answer 19

combine lots of movement to create meaningful movements

Question 20

five regions of basal ganglia

Answer 20

caudate, putamen, glbus pallidus, substantia nigra pars compacta / reticulata

Question 21

striatum (what is it and function)

Answer 21

caudate & putamen collectively
input of basal ganglia (where info comes from)

Question 22

substantia nigra pars compacta

Answer 22

excitatory input to striatum
produces melanin via DA

Question 23

parkinson’s disease

Answer 23

spontaneous movements bc lack of inhibition
lack of substantia nigra

Question 24

optogenetics

Answer 24

selectively activates D1 or D2
d1: more movement
d2: less movement

Question 25

functions of cerebellum (3)

Answer 25

1. coordinating timing and sequence of muscle actions
2. maintenance of muscle tone
3. motor learning
   (more graceful, precision ctrl)

Question 26

cerebellum inputs for movement (where and what)

Answer 26

pons: what do we want to do?
inferior olive, s.c., vestibular nucleus: what happened?

Question 27

signs of cerebellum damage

Answer 27

touch nose with finger from high point = weird path instead of straight
draw weird square instead of straight