The Nerve Impulse Simplified Flashcards Preview

SCT3 Neurology Topic 3 > The Nerve Impulse Simplified > Flashcards

Flashcards in The Nerve Impulse Simplified Deck (9)
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1
Q

When a neuron is not firing, it is said to be what?

A

RESTING

2
Q

When a neuron is resting, what’s going on with its cell membrane?

A

CELL MEMBRANE IS POLARIZED

with electrical gradient

3
Q

Which side of the polarized cell’s electrical gradient contains more sodium (Na+)?

A

OUTSIDE

“Na+ pump” within electrical gradient pumps Na+ out of cell

4
Q

A neuron remains resting and polarized until what level?

A

STIMULUS pushes neuron past
THRESHOLD LEVEL
(the level at which it fires)

5
Q

What happens to Na+ when neuron fires?

A

RUSHES INTO CELL

6
Q

What happens when a neuron’s threshold level is reached?

A

COMPLETE DEPOLARIZATION
+
Na+ CHANNELS OPENED ALONG CELL MEMBRANE OF AXON
+
RESULT IS NERVE IMPULSE or ACTION POTENTIAL

7
Q

What happens after an appropriate amount of Na+ is pumped back out of a neuron?

A

RETURNS TO POLARIZED STATE

8
Q

During what period does the neuron usually not respond to incoming stimuli?

A

REFRACTORY PERIOD

9
Q

When is the refractory period taking place?

A

AS NEURON RETURNS TO NORMAL POLARIZED STATE

returning to “resting”