Neurophysiology of Motor Control

Question 1

What’s the purpose of the soma?

Answer 1

life support for neuron

Question 2

What’s the purposes of dendrites?

Answer 2

pick up messages from other neurons and bring them to soma

Question 2

What’s the purpose of axons?

Answer 2

transmit electric signals away from soma

Question 3

What’s the purpose of axon terminals?

Answer 3

release neurotransmitters to post-synaptic neuron

Question 4

What type of neuron structure is most common?

Answer 4

multipolar

Question 5

Describe the structure of multipolar, bipolar, and unipolar neurons

Answer 5

multipolar: 3 or more processes (dendrites of axons)
bipolar: 2 processes
unipolar: 1 process

Question 6

What are the functions of sensory neurons, motor neurons, and interneurons?

Answer 6

Sensory: sensory receptors ->CNS
Motor: CNS -> effectors
Interneurons: transmit impulses between sensory and motor neurons (mostly in CNS)

Question 7

How many signals can be transmitted at once by a neuron? Is there varying strengths?

Answer 7

Only one signal at a time; one uniform strength

Question 8

What is resting membrane potential for a neuron?

Answer 8

-70 mv

Question 9

What factors contribute to resting membrane potential of a neuron?

Answer 9

Sodium-potassium ATPase, leaky potassium channels and leaky sodium channels

Question 10

How do we get a neuron to fire?

Answer 10

Depolarize (EPSP) and open voltage gated channels to bring resting membrane potential to threshold (-55 mv)

Question 11

How do we stop a neuron from firing?

Answer 11

We take resting membrane potential away from threshold (hyperpolarization–IPSP)

Question 12

Explain the difference between spatial and temporal summation

Answer 12

Spatial summation is the integration of signals from multiple neurons while temporal summation is the integration of signals from one neuron over time. Both are important to see if a neuron will fire

Question 13

What voltage is an action potential?

Answer 13

+30 mV

Question 14

Describe the order of events for an action potential

Answer 14

Depolarization, action potential, repolarization, refractory period, resting state

Question 15

What’s the difference between absolute and relative refractory period?

Answer 15

Absolute: cell can’t be re-stimulated, no action potential can be reached
Relative: action potential can be reached but requires a stronger stimulus

Question 16

What’s the function of the frontal lobe?

Answer 16

voluntary muscle movement, motor skills, cog. functions

Question 17

Function of broca’s area? Where is it?

Answer 17

Speech production; frontal lobe

Question 18

Functional of parietal lobe?

Answer 18

Processes sensory info; has somatosensory cortex

Question 19

Functional of temporal lobe?

Answer 19

Auditory info; has hippocampus (short-term memory)

Question 20

Function of Wernicke’s area?

Answer 20

language comprehension; temporal lobe

Question 21

Function of occipital lobe? Receives input from which lobes?

Answer 21

processes visual info; temporal and parietal lobes

Question 22

Function of insula?

Answer 22

Linked to emotion or the regulation of the body’s homeostasis

Question 23

Purpose of diencephalon?

Answer 23

Regulates homeostasis, reproduction, alertness, strong emotions

Question 24

What structures are in the diencephalon?

Answer 24

Thalamus, hypothalamus, epithalamus, mammillary body

Question 25

Function of cerebellum?

Answer 25

Coordinating muscular activity, fine adjustments to movement

Question 26

Feedforward processing

Question 27

Divergence/convergence

Question 28

Modularity

Question 29

Plasticity

Question 30

Functions of brain stem?

Answer 30

Regulate vital & involuntary functions (heart, breathing, sleep, etc.), midbrain processes advanced sensory (reflexive movements) & transmits signals to cerebral cortex

Question 31

What’s the function of white and gray matter in the spinal cord?

Answer 31

White: info going to/from brain
Gray: local processing of info

Question 32

How does the ratio of gray to white matter change as you go from superior to inferior in the spinal cord?

Answer 32

Gray matter increases as you move down

Question 33

What does the gray matter in the spinal cord contain?

Answer 33

Pos. horn: contains interneurons
Ant. horn: contains cell bodies of motor neurons

Question 34

What does the white matter in the spinal cord contain?

Answer 34

Pos. funiculi: info about touch and limb position
Lat. funiculi: pain
Ant. funiculi: various pathways

Question 35

Describe the corticospinal tract

Answer 35

Info from motor cortex to spinal cord using upper motor neurons (transmits motor info)

Question 36

Describe the dorsal columns medial lemniscus

Answer 36

Carries info related to fine touch, vibration, and proprioception

Question 37

Name the 3 deep nuclei of the cerebellum

Answer 37

Fastigial nucleus, interposed nucleus, dentate nucleus

Question 38

What structures connect the cerebellum to the brainstem?

Answer 38

Superior, middle, and inferior peduncles

Question 39

Name the lobes of the cerebellum

Answer 39

Anterior, posterior, and flocculonodular

Question 40

Describe how the vestibulocerebellum works

Answer 40

receives vestibular & visual input, vestibular feedback, eye movement

Question 41

Describe how the spinocerebellum works

Answer 41

receives feedback from spinal cord
- vermis: controls more proximal body
- intermediate hemisphere: controls more distal parts

Question 42

Describe how the cerebrocerebellum works

Answer 42

Inputs and outputs connect to cerebral cortex, plan and execute movement, connects motor learning and working memory

Question 43

Name the layers that organize the neurons in the cerebellar cortex

Answer 43

Deep->Superficial: Granular, Purkinje, and Molecular