Intro to Neuroscience, Chapter 9 Review

What are the three types of muscles?

Smooth, cardiac, and skeletal.

What purpose does smooth and cardiac muscle serve?

Smooth muscles (digestive/organs) and cardiac muscles (heart) aren’t that relevant to movement

What purpose do skeletal (striate) muscles serve?

Facilitate voluntary responses to the environment

What happens at neuromuscular junction?

Synapses (passes) between motor neurons and muscle fibers.

How do fast -twitch fibers relate to physical activity?

Facilitate quick bursts of movement (anaerobic) and fatigue very quickly (ex. sprinting)

How do slow-twitch fibers relate to physical activity?

Facilitate less vigorous activity and don’t really fatigue (aerobic) (ex. walking)

What are the functions of proprioceptors?

Sense stretch in muscles, sends a message in spinal cord to counteract the stretch and maintain balance.

How are the behaviors produced by proprioceptors non-voluntary?

Because the tendon struck by the hammer is a proprioceptor which triggers the reflex arc (ex. walking)

Where is the primary motor cortex?

Behind the supplementary motor cortex, in front of the central sulcus.

What sort of behaviors are driven by the motor cortex?

Driving or typing, etc.

What are central pattern generators?

Mechanisms in the spinal cord that produce patterns of output (ex. sneezing, smiling, “wet dog shake”)

Are movements such as sneezing and “wet dog shake” ballistic movements?

They are because once they’re started they can’t be stopped; They are also not voluntary (ex. A cat will sharpen its claws even after being declawed)

Where is the premotor cortex located?

Directly behind the prefrontal cortex.

How does the premotor cortex contribute to movement?

Active prior to complex movements taking place (ex. waiting for space to open up before switching lanes on the road)

Are movements lead by the prefrontal cortex voluntary? Are they ballistic movements?

Yes, because it anticipates likely outcome of actions, something people aren’t fully capable of doing until they are around the age of 25.

What are the three structures of the basal ganglia?

Globus pallidus, putamen, caudate nucleus.

How does the basal ganglia interact with the thalamus to control movement?

The thalamus is always generating motor output, the three structures of the BG form a complex inhibition system fueled by dopamine.

What are the two types of movement?

Voluntary (slower and deliberate) and elicited (fast and less-controlled) movements.

What does lateral corticol spinal tract control?

Controls voluntary movements of arms and legs.

What does the medial corticol spinal tract control?

Coordination of the entire body or movements that require both sides of the body.

What does the cerebellum do that is more than “balance and coordination”?

It also plays an important role to complicated movements and stimuli.

What causes Parkinson’s disease?

Degeneration of substantia nigra, loss of dopamine needed to run basal ganglia.

What is the difference between early-onset and late-onset when it comes to Parkinson’s disease?

Early-onset is caused by genetics passed down by parents or family members while late-onset is caused by old age.

How can Parkinson’s be treated?

L-Dopa, a precursor to dopamine that crosses the blood-brain barrier since dopamine won’t cross itself.

What are the downsides to using L-Dopa?

After some time, patients can develop a tolerance for the drug. High doses can also cause the patient to appear schizophrenic.

What causes the development of Hunington’s disease?

Dominant gene of Chromosome 4 produces a mutant form of protein called “Huntingin”, build up of this protein destroys the structures of the basal ganglia which is fatal with no known cure.