Neurophysiology II

Question 1

Soma

Answer 1

Cell body of neuron

Question 2

Dendrites

Answer 2

Branches of neuron specialized to receive signals

Question 3

Myelin

Answer 3

Fat cells located along axon of neuron

Question 4

Axon

Answer 4

Extension of neuron through which electrical signals travel

Question 5

Axon Terminal

Answer 5

Branches of neuron specialized to send signals

Question 6

Input Zone

Answer 6

Where neurons collect, process, and accumulate information

Question 7

Integration Zone

Answer 7

Where the decision to produce a neural signal is made

Question 8

Conduction Zone

Answer 8

Where the electrical signal is transmitted over a great distance

Question 9

Output Zone

Answer 9

Where the neuron transfers information to another neuron

Question 10

Action Potential

Answer 10

When the membrane potential of a specific cell rapidly rises and falls

Question 11

Sodium Ion Channel

Answer 11

Protein through which Na+ passes into the cell
- Concentration of Na+ greater outside of cell than inside

Question 12

Potassium Ion Channel

Answer 12

Protein through which K+ passes
- Concentration of Ka+ greater inside of cell than outside

Question 13

Sodium-Potassium Pump

Answer 13

Binds three sodium ions and a molecule of ATP to pass Na+ through
- new shape allows two K+ bind

Question 14

Resting Membrane Potential

Answer 14

Negative (-65 mv)

Question 15

Depolarization

Answer 15

Increase in membrane potential
- Only voltage-gated Na+ ion channels open
- Na+ ions rush into cell

Question 16

Repolarization

Answer 16

Decrease in membrane potential
- K+ ion channels open
- K+ ions leave the cell
- Na+ ion channels close

Question 17

Hyper-polarized State

Answer 17

Membrane potential is below resting state
- Action potential not possible

Question 18

Conduction Velocity

Answer 18

The speed of propagation of the action potential
- Dependent on diameter of axon

Question 19

Saltatory Conduction

Answer 19

Insulated axon is able to conduct electrical signals over great distances
- Electrical current skips along length of axon
- Increased speed

Question 20

Nodes of Ranvier

Answer 20

Reestablishes ion flow on exposed axon with influxes of sodium ions
- Prevents the electrical charge diminishes over long distances

Question 21

Multiple Sclerosis

Answer 21

Condition that causes demyelination
- Slower nerve impulses
- Loss of nerve function

Question 22

Synapse / Synaptic Cleft

Answer 22

Location where a dendritic spine meets an axon terminal
- Release of neurotransmitters

Question 23

Synaptic Vesicles

Answer 23

Composed of phospholipid bilayer
- Holds neurotransmitters before they are released into the synapse

Question 24

Receptors

Answer 24

Proteins ( and ion channels) specific to neurotransmitters
- Change shape when bound to neurotransmitters
- Open to allow ions in to neuron

Question 25

Anterograde Transport

Answer 25

Transport of synaptic vesicles down from the cell body to the axon terminal

Question 26

Retrograde Transport

Answer 26

Transport of synaptic vesicles up from the axon terminal to the cell body

Question 27

Microtubule Network

Answer 27

Process by which motor proteins transport synaptic vesicles down the length of the axon - Requires ATP

Question 28

Gap Junction

Answer 28

Synapse that can transmit electrical signals (action potential) - Ion channels on each neuron are directly linked to each other - Similar to structures in human heart

Question 29

Refractory Period

Answer 29

Period in which another action potential cannot be fired until the membrane potential returns to resting state