4: Action potentials Flashcards
Describe the relationship between the permeability of the membrane to the conductance/action potential
The more permeable the membrane to a particular ion, the greater the conductance of the membrane to that ion
What are transmembrane domains?
Protein of the voltage gated Na+ channel has 4 subunits which are already connected. The parts in the subunit are called the transmembrane domain
What type of channel are Na+
Voltage gated
What are the three sections of voltage gated Na+ channels
- Voltage sensor -ON
- Selectivity filter
- Inactivation gate -OFF
Describe how the inactivation gate works
“ball and chain model”
- Look through lecture slides
What drug are voltage gated Na+ channels blocked by?
Tetrodotoxin
What are voltage gated K+ channels blocked b
tetrathylammonium
Describe the action/movement of action potentials
slides
- Stimulus-gated Na+ channels open
- Voltage-gated Na+ channels open
- Voltage-gated Na+ channels close
- Voltage-gated K+ channels open
- Voltage-gated K+ channels close
Describe the absolute refractory period
slides
Describe the relative refractatory period
slides
List methods to improve action potential conduction velocity
- Increase axon diameter -decrease r(in)
- Increase axon insulation -increase m
- Saltatory conduction between nodes of Ranvier