Nervous System: Action Potential Flashcards
where do action potentials occur?
only in the cell membrane of a neuron’s axon
what is an action potential
a wave of electrochemical activity that allows a neuron to carry a signal over a distance
a typical neuron has what charge inside when at rest
negative polarity
how ions separated around a neuron
- outside the neuron: high sodium & low potassium
- inside the neuron: high potassium & low sodium
what is electrochemical activity
-the polarity inside a neuron going from negative to positive and vice versa
what happens when a neuron is affected by a stimulus
it causes the Na+ gates to open and Na+ ions to diffuse into the axon
what happens after Na+ ions stop diffusing into axon
the K+ gates open and K+ ions diffuse out of axon
when an axon is negative on the inside due to an abundance of the wrong ions it must do what
Re-establish
how does an axon Re-establish itself
by using the the Na+/K+ pump that moves the Na+ outside and K+ inside
the time when an axon is Re-establishing itself and cannot produce another Action Potential is called what
Refractory Period
the gaps between the myelin sheath wrapped around an axon is called what
Nodes of Ranvier
Action Potentials always travels how
in one direction at a very high velocity
what is the purpose of the Refractory Period and Nodes of Ranvier
to cause Action Potentials to move away from neuron cell body by jumping “gap to gap” in one direction
what is the Na+/K+ ion ratio for a neuron at at rest
- outside: 145 Na to 4 K
- inside: 150 K to 12 Na
