Flashcards in Background Knowledge Deck (6)
What is membrane potential?
Voltage difference across a membrane
What is equilibrium potential?
In a single ion system, the voltage at which there is no net flow of that species of ion across the membrane
What is reversal potential?
- Nernst potential
- The voltage at which there is no net flow of ions (of all species) across the membrane (if there is just one ion it's same as equil. potential)
- Can be calculated using Nernst equation
- If one ion Chanel type dominates (high permeability) membrane potential tends towards reversal potential for that ion
How do electrical signals transmit information?
By travelling along the dendrites and axons of neurones
Describe the two forms of electrical signals
- Action potentials, brief depolarisations generated by voltage-gated Na and K channels. They propagate actively through the neurone and do not decrement in size
- Graded responses, passively propagating, decrementing changes in membrane potential