11.1 - Neuron Function and Synapse Flashcards
What’s a membrane potential?
The difference in charge between the inside of the axon and the outside of the axon.
- The potential is measured from inside
Resting Membrane Potential?
When the nerve cell is not transmitting a signal.
Resting Membrane Potential Voltage?
-70mV,
- 70mV more negative on the inside the axon than the outside.
How is the Resting Membrane Potential Maintained?
Sodium-potassium pumps keep the sodium ions out and potassium ions inside.
Polarization
Process of generating a resting membrane potential of -70mv.
- Charged neuron, ready to send message.
How do neurons become polarized?
Different things:
- Large protein molecules are present inside the cell, and they’re negatively charged. They can’t pass.
- Cell membrane is nearly impermeable to small negatively charged ions, such as chloride ions. So, chloride ions in the cell contribute to a negative charge.
- sodium-potassium exchange pump: It uses ATP to transport sodium ions out of the cell and potassium ions into the cell.
Sodium-Potassium Exchange Pump Currency
It exchanges three sodium ions for two potassium ions.
What happens as a result of the SP Pump?
A disequilibrium is established, there’s more positive charge outside and a slightly negative charge inside.
Leaky K+ channels
Action potential