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Flashcards in Spikes Deck (13)
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1
Q

What is a spike?

A

A brief pulse-like electrical event involving the sudden opening of sodium channels

2
Q

What is the membrane potential inside the cell when the sodium channels open?

A

+60mV

3
Q

What do neurons do?

A

Receive, sort out and transmit electrical signals

4
Q

How is long distance communication achieved in a single neuron?

A

Spikes

5
Q

What do the dendrites and axons do in a neuron?

A

Dendrites: receive the electrical signal (chemically activated channels)

Axon: carries the signal from one end of the neuron to the other (voltage activated channels)

6
Q

What are cells called that make spikes?

A

Excitable

7
Q

How does a spike travel?

A

Propagation

8
Q

How is a spike triggered

A

Stimulus causes a local electrical signal that is strong enough to exceed the threshold

9
Q

Does spike amplitude change depending on the size of the stimulus?

A

No

10
Q

What does the speed of spike travel depend on?

A

Axon width: wide is quicker
Temperature: warmer is quicker
Myelin: insulation

11
Q

What is it called when a spike jumps from node to node?

A

Saltatory conduction

12
Q

What is the refractory period?

A

Can not produce another spike for a period of 1-2ms

13
Q

What did Hodgkin and Huxley do/find?

A

Experimented on giant axons in a squid using intracellular recordings to show the polarity reverses during a spike

Also had a theory on the sequence of events in ion channels