1. Other names for Action Potential
    • Spike
    • Nerve Impulse
    • Discharge
  2. Membrane potential moves from ____mV to ____ mV for a very brief time
    -65mV to +40mV
  3. Rising Phase:
    Rapid depolarization of membrane to +40mV
  4. Problems with Na+ channels:
    • Generalized epilepsy with febrile seizures
    • •Increase temp.=seizures
    • •Due to slowing of Na+ channel inactivation = prolonging of APs
  5. Problems with Na+ channels:
    Tetrodotoxin (TTX)
    • In puffer fish
    • Clogs Na+ pore = blocks AP
    • Result = FATAL (paralysis of diaphragm and heart muscle due to nerve and muscle block)
    • If served correctly: numb around mouth
  6. Problems with Na+ channels:
    • Clams, muscles, shellfish that feed on certain dinoflaggelates
    • Blocks Na+ channel
    • Result = FATAL (paralysis of diaphragm due to nerve and muscle block)
  7. Problems with Na+ channels:
    • Skin on Columbian frog
    • Causes Na+ channels to open at more negative Vm and stay open longer = scrambles AP code/info being sent
  8. Voltage-gated K+ channels are involved in what _______ phase as it helps with repolarization
    Falling phase
  9. Multiple Sclerosis
    • Demyelinating Disease
    • Symptoms: Weakness, impaired coordination, vision, and speech
    • Cause of disease is not well understood
    • Cause of sensory and motor problems: MS attacks myelin sheath of axons
    • Multiple: many areas of nervous system at once
    • Sclerosis: "hardening" lesions around axons
    • Diagnose:
    • •MRI
    • •Conduction velocity: slowed by destruction of myelin
  10. Guillain-Barre Syndrome
    • Attacks myelin of PNS
    • •slows conduction velocities
    • Saltatory conduction is disrupted
Card Set
Action Potential Notes