Anatomy lab - Action Potential

Question 1

What allows for the action potential to occur?

Answer 1

Voltage-gated Na+ channels

Question 2

What are the two voltaged-gated channels?

Answer 2

Na+ and K+

Question 3

At resting potential, voltage-gated Na+ channels are what?

Answer 3

Closed

Question 4

Conformational changes open voltage-gated channels when the membrane is what?

Answer 4

Depolarized

Question 5

What happens during resting potential?

Answer 5

Both voltage gated Na+ and K+ channels are
closed

Question 6

What is initial depolarization?

Answer 6

Some Na+ channels open and if so then the threshold is surpassed and an action potential is initiated.

Question 7

What happens during the rising phase of action potential?

Answer 7

Na+ channels open quickly. K+ channels are still closed.

Question 8

What happens during the falling phase of action potential?

Answer 8

Na+ channels self-inactivate, K+ channels are open.

Question 9

Why does the membrane potential increase during depolarization of the action potential?

Answer 9

The voltage gated Na+ channels are open, but the voltage gated K+ channels have not opened yet.

Question 10

Why does the membrane potential decrease during hyperpolarization of the action potential?

Answer 10

The voltage gated K+ channels open, the voltage gated Na+ channels close.

Question 11

What does action potential jump from on the axon?

Answer 11

Node to node

Question 12

What wraps around the axon?

Answer 12

Schwann cells

Question 13

What does Schwann cells form?

Answer 13

myelin sheath

Question 14

What is the term for the axon terminal?

Answer 14

Pre-synapse

Question 15

What is the term for the middle terminal?

Answer 15

Synapse

Question 16

What is the term for dendrite?

Answer 16

Post-synapse

Question 17

What synapse would likely INCREASE firing the action potential?

Answer 17

Excitatory synapses

Question 18

What synapse would likely DECREASE firing the action potential?

Answer 18

Inhibitory synapses

Question 19

Excitatory postsynaptic
potential (EPSP)

Answer 19

Depolarization, Na+ influx

Question 20

Inhibitory postsynaptic
potential (IPSP)

Answer 20

Hyperpolarization, K+
efflux, Cl– influx

Question 21

EPSP + IPSP

Answer 21

Depolarization and
hyperpolarization
stimuli applied

Question 22

Avg. mV for resting potential

Answer 22

-70

Question 22

What are the 3 types of gates?

Answer 22

Closed, active, inactive

Question 23

Avg. mV for threshold potential

Answer 23

-55

Question 24

Avg. mV for action potential

Answer 24

+30

Question 25

When neurons transmit electrical signals what can vary?

Answer 25

Frequency

Question 26

In a neuron, what is the structure that separates ions?

Answer 26

Membrane

Question 27

The intercellular environment of a neuron is more what?

Answer 27

Negative relative to the outside of the cell.

Question 28

The extracellular environment is more what?

Answer 28

Positive relative to the inside of the cell.

Question 29

Which ions are in the intracellular space of a neuron?

Answer 29

Potassium

Question 30

Which ions are in the extracellular space outside a neuron?

Answer 30

Sodium

Question 31

What are the 3 types of ion channels?

Answer 31

Voltage-gated channel, mechanically-gated channel, ligand-gated channel

Question 32

How do you generate an action potential in a neuron?

Answer 32

To depolarize its resting neurons.

Question 33

What is the ion responsible for depolarization of the neuron?

Answer 33

Sodium ions

Question 34

What is the ion responsible for repolarization of the cell membrane?

Answer 34

Potassium

Question 35

Nodes of Ranvier

Answer 35

The gaps in the myelin sheath of a neurons

Question 36

Myelin sheath

Answer 36

The structure that affects the transmission speed of an action potential

Question 37

What is the cell body?

Answer 37

The cells life support center

Question 38

What is a dendrite?

Answer 38

Receive messages from other cells

Question 39

What is the axon?

Answer 39

Passes messages away from the cell body to other neurons

Question 40

What is a neural impulse?

Answer 40

Action potential; electrical signal traveling down the axon

Question 41

What is the terminal branches of axon?

Answer 41

Form junctions with other cells