Bioelectricity

  1. Graded Potentials and The Action Potential
    1. Graded Potentials
      1. Definition and Properties
        1. Amplitude Modulation
          1. Localized Changes in Membrane Potential
            1. Proportional Response to Stimulus
            2. Decremental Conduction
              1. Distance-Dependent Decay
                1. Membrane Time Constant
                  1. Membrane Length Constant
                    1. Cable Properties of Neurons
                    2. Summation
                      1. Temporal Summation
                        1. Repeated Stimuli Over Time
                          1. Integration Window
                          2. Spatial Summation
                            1. Multiple Inputs at Different Locations
                              1. Dendritic Integration
                              2. Linear vs. Nonlinear Summation
                              3. Types of Graded Potentials
                                1. Excitatory Postsynaptic Potentials (EPSPs)
                                  1. Mechanisms of Generation
                                    1. Effect on Membrane Potential
                                      1. Duration and Amplitude
                                      2. Inhibitory Postsynaptic Potentials (IPSPs)
                                        1. Mechanisms of Generation
                                          1. Effect on Membrane Potential
                                            1. Shunting Inhibition
                                            2. Receptor Potentials
                                              1. End-Plate Potentials
                                              2. Integration at the Axon Hillock
                                                1. Trigger Zone Properties
                                                  1. Threshold Determination
                                                    1. Action Potential Initiation
                                                  2. The Action Potential
                                                    1. Threshold Potential
                                                      1. Definition and Determinants
                                                        1. Role in Action Potential Initiation
                                                          1. Factors Affecting Threshold
                                                            1. Accommodation
                                                            2. Voltage-Gated Ion Channels
                                                              1. Voltage-Gated Sodium Channels
                                                                1. Structure and Function
                                                                  1. Voltage Sensor
                                                                    1. Activation Gate
                                                                      1. Inactivation Gate
                                                                        1. Kinetics of Gating
                                                                        2. Voltage-Gated Potassium Channels
                                                                          1. Structure and Function
                                                                            1. Delayed Rectifier Channels
                                                                              1. A-type Channels
                                                                                1. Calcium-Activated Potassium Channels
                                                                                2. Other Voltage-Gated Channels
                                                                                  1. Calcium Channels
                                                                                    1. Chloride Channels
                                                                                  2. Phases of the Action Potential
                                                                                    1. Resting State
                                                                                      1. Baseline Membrane Potential
                                                                                        1. Channel States
                                                                                        2. Depolarization (Rising Phase)
                                                                                          1. Sodium Influx
                                                                                            1. Positive Feedback Mechanism
                                                                                              1. Regenerative Process
                                                                                              2. Peak Potential
                                                                                                1. Maximum Depolarization
                                                                                                  1. Approach to Sodium Equilibrium Potential
                                                                                                  2. Repolarization (Falling Phase)
                                                                                                    1. Potassium Efflux
                                                                                                      1. Sodium Channel Inactivation
                                                                                                        1. Return Toward Resting Potential
                                                                                                        2. Hyperpolarization (Undershoot)
                                                                                                          1. Delayed Potassium Channel Closure
                                                                                                            1. Afterhyperpolarization
                                                                                                          2. The Refractory Period
                                                                                                            1. Absolute Refractory Period
                                                                                                              1. Inactivation of Sodium Channels
                                                                                                                1. No New Action Potential Possible
                                                                                                                  1. Duration and Determinants
                                                                                                                  2. Relative Refractory Period
                                                                                                                    1. Partial Recovery of Sodium Channels
                                                                                                                      1. Higher Threshold for Action Potential
                                                                                                                        1. Reduced Amplitude Response
                                                                                                                        2. Functional Significance
                                                                                                                          1. Unidirectional Propagation
                                                                                                                            1. Maximum Firing Frequency
                                                                                                                          2. All-or-None Principle
                                                                                                                            1. Definition and Implications
                                                                                                                              1. Threshold Concept
                                                                                                                                1. Amplitude Independence
                                                                                                                                2. Action Potential Initiation
                                                                                                                                  1. Trigger Zone
                                                                                                                                    1. Critical Depolarization
                                                                                                                                      1. Positive Feedback Loop

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                                                                                                                                  2. The Resting Membrane Potential

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                                                                                                                                  4. Propagation of the Action Potential