Nervous System

Question 1

Nerve impulse/buzz

Answer 1

Action potential

Question 2

Resting neuron

Answer 2

Negative inside, positive outside

Question 3

Resting membrane potential?

Answer 3

-70 mV

Question 4

What ions are outside/inside neuron?

Answer 4

Sodium outside, potassium inside

Question 5

Sodium potassium pump

Answer 5

Protein in neuron membrane, pumps 3 Na out, 2 K in

Question 6

What does the sodium potassium pump create

Answer 6

Electrochemical gradient, the difference in positive/negative

Question 7

Voltage gated channels

Answer 7

Majority of membrane channels, they open and close in response to voltage change

Question 8

What channel opens at -55 mV?

Answer 8

Na

Question 9

Graded potential (localized)

Answer 9

When only a few channels open and a bit of sodium enters the cell

Question 10

Threshold for action potential

Answer 10

-55mV

Question 11

What happens when it hits -55mV?

Answer 11

All the sodium channels open and positive sodium ions rush in, depolarizing the cell

Question 12

What is the result of an action potential

Answer 12

Sends an electrical signal down the axon

Question 13

Repolarization

Answer 13

Voltage gated potassium ion channels open to let potassium ions flow out to rebalance charges

Question 14

Refractory period

Answer 14

When an axon is in the middle of an action potential and all the ion channels are open

Question 15

Peak depolarization

Answer 15

40mV

Question 16

Weak stimulus

Answer 16

Triggers less frequent action potentials, like if your brain is telling you to do something

Question 17

Action potential speed

Answer 17

Faster in reflex pathways, slower in glands, gut, blood vessels

Question 18

Saltatory conduction

Answer 18

When a action potential travels down the myelin sheath, it’s much faster

Question 19

What happens when an action potential reaches the end of the neuron?

Answer 19

Hits the synapse which then translates it into a different type of signal

Question 20

Electrical synapse

Answer 20

Immediate signal, like a group text

Question 21

Chemical synapse

Answer 21

Takes more time to be received and read but used more often and easier to control, sending signal to only certain people i.e. direct message

Question 22

Why is electrical synapse so fast

Answer 22

Send an ion current flowing directly from one neuron to another using gap junctions. Signal is never converted from the pure electrical state

Question 23

When is electrical synapse used?

Answer 23

Muscle cell of heart

Question 24

Chemical synapses use what instead of raw electricity

Answer 24

Neurotransmitters (chemical signals) that diffuse across synaptic gap

Question 25

Where is receptor region on postsynaptic neuron.

Answer 25

Dendrite or cell body

Question 26

Where is the voltage gated calcium channels?

Answer 26

Presynaptic terminal

Question 27

What do the calcium channels do?

Answer 27

Open and release calcium into neurons cytoplasm, causing the synaptic vessels carrying the neurotransmitters to fuse with the membrane and release them

Question 28

Conversion of action potential from electrical to chemical

Answer 28

Down the axon: electrical Across the synaptic cleft: chemical Back down the other axon: electrical

Question 29

How does the chemical signal turn back into electrical?

Answer 29

When neurotransmitters bind to receptors

Question 30

Excitatory neurotransmitters

Answer 30

They depolarize the postsynaptic neuron (EPSP) and push the neuron closer to the threshold to make an action potential more likely

Question 31

Inhibitory neurotransmitter

Answer 31

IPSP push the neuron further from the threshold, making an AP harder to achieve. Hyper polarization

Question 33

What happens to neurotransmitters after delivering their message

Answer 33

Degrade, or diffuse back across synapse to be reabsorbed (reuptake)