Session 4: Changing Membrane Potential Flashcards
Define depolarisation.
When inside the cell becomes less negative.
Define hyperpolarisation
Inside the cell becomes more negative
What is conductance?
The contribution each Ion makes to the membrane potential (dependant on the permeability of the membrane to that Ion)
What is the name of the equation that links a number of ion channel permeabilities?
The GHK (Goldman-Hodgkin Kat) equation.
What is the GHK equation useful for?
Comparing 2 cell types.
Name the 3 types of gating.
- Ligand
- Voltage
- Mechanical
What is ligand channel gating?
Channel opens or closes in response to the binding of a chemical ligand.
What is voltage channel gating?
Channels open or close in response to a change in membrane potential.
What is mechanical channel gating?
A channel opens or closes in response to membrane deformation.
Give an example of ligand gated channels.
Channels at synapses I.e. ACh or serotonin
Give an example of voltage gated channels.
Nerve cells action potentials.
Give an example of mechanical gated channels.
Stretch receptors and hair receptors in inner ear
What do excitatory post synaptic potentials (EPSP) cause?
Membrane depolarisation
What do inhibitory post synaptic potentials (EPSP) cause?
Membrane hyperpolarisation
