Please enable JavaScript.
Coggle requires JavaScript to display documents.
Action Potentials (Diffusion potential (Charge of each ion, Permeability…
Action Potentials
Diffusion potential
Charge of each ion
Permeability of each ion
Concentration difference of each ion
Ligand-Gated vs Voltage-Gated
Ligand-Gated
Graded Potentials
Hyper-polarizing
Make neurons calm
IPSP: Inhibitory Post-Synapatic Potential
Depolarizing
Make neurons active
EPSP: Excitatory Post-Synapatic Potential
Trigger: Ligand, self-induced change in ion permeability
Ion movement: Na+, K+, Cl-, Ca++, by various means
Potential change: Depolarization or hyper-polarization
Magnitude: Depends on magnitude of trigger
Duration: Varies
Refractory: None
Propagation: Decreases over distance
Voltage-Gated
Action Potentials
All or None
Trigger: Depolarization to threshold by neighboring graded or action potential
Ion movement: Coordinated Na+ and K+ movement
Potential change: Always depolarization followed by hyper-polarization
Magnitude: All-or-none magnitude
Duration: Constant
Refractory: Absolute and relative
Propagation: Constant over distance
Spatial vs Temporal Summation
Spatial
Action potential generated from MULTIPLE neurons
Temporal
Action Potential generated from SINGLE neurons
Signal Transmission
Resting Potential (-90 mV)
Na+ channels open and Na ions diffuse in
Depolarization
Threshold reached (+40 mV)
Action Potential released
K+ channels open (slower) and Na+ channels close
Repolarization
Undershoot/Hyperpolarization
1 more item...
Plateau
Cardiac muscle and some smooth muscles
Opening of voltage-gated slow (Na and/or Ca) channels
1 more item...
Ventricular Muscle AP (several plateaus)
Involves calcium channels
4 phases
1 more item...
Rhythmicity (Pacemaker Activity)
Heart, most smooth muscles, and some neurons
Opening of slow Na+ and/or Ca++ channels
1 more item...
Extracellular K+ = - 94mV
Extracellular Na+ = 70 mV