Human Phys 2.1 Flashcards
Diffusion potential
Potential difference generated across a membrane when an ion diffuses down its concentration gradient
What is the only way diffusion potentials can be generated?
If the membrane is permeable to the ion
What does the magnitude of the diffusion potential depend on?
Size of concentration gradient
Equilibrium potential
Diffusion potential that exactly balances or opposes the tendency for diffusion down the concentration gradient
When did electrochemical equilibrium occur?
When the chemical and electrical driving forces acting on an ion are equal and opposite
When do membrane potentials arise?
When there is a difference in electrical charge between both sides of a membrane
What can charge differences result from?
Passive ion diffusion (open Na+ channel)
Electrogenic pumping (Na+K+ pump)
Why does K+ play an essential role in balancing Na+ in ICF?
Due to K+ leak channels (K+ can move while membrane is at rest)