Membrane & Action Potential Flashcards
What is #1?
Depolarization phase
What is #2?
Repolarization phase
What is #3?
Undershoot
What is the green line?
Resting Potential
What is the yellow line?
Threshold
How are graded potential triggered?
Ligand, self-induced change in ion permeability
How are action potentials triggered?
Depolarization to threshold
How do ions move in graded potential?
Various means thru Na+, K+, Cl-, or Ca++
How to ions move in action potential?
Coordinated Na+ and K+ movement
What are the potential change in graded potential?
Depolarization or hyperpolarization
What are the potential changes in action potential?
Always starts w/ depolarization followed by hyperpolarization
What is the magnitude in graded potential?
Depends on strength of magnitude
What is the magnitude in action potential?
All-or-none magnitude
What is the duration in graded potential?
Varies
What is the duration in action potential?
Constant
Is there a refractory period in graded potential?
No
What is the propagation in graded potential?
Decreases over distance
What is the propagation in action potential?
Constant over time
Why do plateaus occur in action potential?
- Opening of voltage-gated slow (Na and/or Ca) channels
- Slower opening of voltage-gated K channels
What is C?
K+ channel
What is E?
More K+ channel
What is D?
More Na+ channel
What is A?
Fast Na+ channel
What does this graph show?
Ventricular muscle
What is B?
Slow Ca++ channel
What is A?
K+ channels close, slow Na+ channels opening
What is C?
Ca++ channel close, K+ channel open
What is F?
Slow depolarization (pacemaker potential)
What is B?
Ca++ channels open
What is D?
Ca++ permeability decreases
What is E?
K+ permeability increases
What graph does this show?
Pacemaker found in:
- Heart
- Most smooth muscles
- Some neurons
