session 9

Question 1

smooth muscle

Answer 1

digestive/organs, aren’t relevant to movement

Question 2

cardiac muscle

Answer 2

heart, not relevant to movement

Question 3

skeletal (striate)

Answer 3

muscles are our primary focus, voluntary responses to the environment

Question 4

muscles

Answer 4

innervated by only a single axon, to avoid conflicting motor messages

Question 5

The Neuromuscular Junction

Answer 5

synapses between motor neurons and muscle fibers, mostly use acetylcholine (ACh, causes a singular contraction in a muscle)

Question 6

Fast Twitch fibers

Answer 6

facilitate quick bursts of movement, and fatigue very quickly (sprinting)
anaerobic- build up a debt to pay back later

Question 7

Slow Twitch Fibers

Answer 7

Facilitate less vigorous activity and don’t really fatigue (walking)
aerobic-pay as you go

Question 8

Proprioceptors

Answer 8

sense stretch in muscles sends a message to spinal cord to counteract the stretch and maintain balance

Question 9

Reflex arc

Answer 9

the tendon struck by the hammer is a proprioceptor, which is what triggers it

Question 10

motor cortex

Answer 10

Primary motor cortex (frontal lobe), complicated motor tasks such as driving or typing, less important for simpler actions like smiling or coughing

Question 11

central pattern generators

Answer 11

mechanisms in the spinal cord that produce patters of output, sneezing, smiling, “wet dog shake”, natural smiles

Question 12

“ballistic movements”

Answer 12

meaning once they’re started they can’t be stopped, like a wet dog shake

Question 13

The Basal Ganglia

Answer 13

3 structures (globus, pallidus, putamen, caudate nucleus), can tell the thalamus to stop, inhibiting the motor movement

Question 14

Prefrontal cortex

Answer 14

anticipates likely outcome of actions, when distracted makes silly motor mistakes without realizing it

Question 15

thalamus

Answer 15

always generating motor output, the 3 structures of the basial ganglia form a complex inhibition system fueled by dopamine

Question 16

voluntary movements

Answer 16

basal ganglia, slower and more deliberate

Question 17

elicited movements

Answer 17

spinal cord and reflexes, faster and less controlled

Question 18

corticospinal tracts

Answer 18

starts in the cortex and goes to the spine, the pathway through your brain (getting refined) going down to your body

Question 19

Cerebellum

Answer 19

movements involving timing, coordination, adjustment from trial to trial, people with damage to the cerebellum struggle with the finger-to-nose test

Question 20

Parkinson’s Disease

Answer 20

muscle rigidity, difficulty initiation movements, can move well enough once started but need a pattern or a “path” to guide them
causes: degeneration of substantia nigra, loss of dopamine needed to run basal ganglia

Question 21

Parkinson’s Disease treatments

Answer 21

L-Dopa is a precursor to dopamine that crossed the blood-brain barrier (dopamine itself won’t cross)
helps for a time, but tolerance develops and side effects are challenging

Question 22

Parkinson’s Prevention

Answer 22

stimulant drugs are thought to both prevent Parkinson’s onset and slow its progression

Question 23

Huntington’s Disease

Answer 23

A dominant gene on chromosome 4 produces a mutant form of a protein called “huntingtin”
the build-up of this protein ultimately destroys the structures of the basal ganglia
severs movement disorders emerge, ultimately fatal, no cure