Potentials Flashcards
What part of a neuron is covered in sodium/potassium channels?
The whole neuron
What is the common resting potential?
-70 mV
What does -70 mV mean?
The inside of the neuron is 70 mV more negatively charged than the outside
Why does sodium want to move inside the neuron after being pumped out?
Concentration gradient
Electrostatic gradient
What is an electrostatic gradient?
The negative charge inside the neuron attracts the positive charge outside the neuron
When do the sodium/potassium channels pump?
Constantly
What does it mean to be polarized?
One side is relatively positive and the other is relatively negative
What is an action potential?
A wave-like depolarization of the neuron (one section at a time)
What causes the protein channels/gates to open up?
A positive charge that moves through the neuron
Do the gates stay open forever?
No.
Once the positive charge passes the gates close again
What gets let through the gates?
Sodium gets let through the gates into the neuron
What is resting potential
The neuron has polarized it’s membrane
When do the potassium gates open?
Slightly after the sodium gates have opened
What does a Schwann cell do during an action potential?
Makes the sodium channels on the other side open when the positive charge reaches it
What causes hyperpolarization?
Some potassium outside hasn’t been pumped in yet (for a short period of time)
What is the sodium to potassium ratio being pumped?
3 sodiums out
2 potassiums in
3:2
What is an action potential across a myelinated sheath called?
Saltatory conduction
What is a threshold level?
The minimum amount of depolarization required to create an action potential
How does an inhibitor synapse polarize a neuron?
Opens potassium channels which moves potassium out of the neuron making the inside “more negative”
What is the refractory period?
Recovery time for the synapse to go back to its resting potential
Draw a synapse and potentials!
5 times
Draw the mV as a function of time graph
5 times!!
