Excitable Cell Physiology

  1. Passive Electrical Properties and Graded Potentials
    1. Membrane Resistance
      1. Definition and Determinants
        1. Ion Channel Density
          1. Channel Open Probability
            1. Membrane Area
            2. Specific Membrane Resistance
              1. Units and Typical Values
                1. Variation Among Cell Types
                2. Impact on Signal Propagation
                  1. Current Flow Patterns
                    1. Voltage Drop Across Membrane
                  2. Membrane Capacitance
                    1. Definition and Determinants
                      1. Membrane Area
                        1. Dielectric Properties
                          1. Membrane Thickness
                          2. Specific Membrane Capacitance
                            1. Units and Typical Values
                              1. Consistency Across Cell Types
                              2. Effect on Membrane Charging
                                1. Capacitive Current
                                  1. Time Course of Voltage Changes
                                2. Cable Properties of Neurons
                                  1. Axial Resistance
                                    1. Cytoplasmic Resistance
                                      1. Axon Diameter Effects
                                      2. The Membrane Time Constant
                                        1. Calculation from Rm and Cm
                                          1. Biological Significance
                                            1. Influence on Temporal Summation
                                              1. Variation Among Neurons
                                              2. The Length Constant
                                                1. Calculation and Derivation
                                                  1. Biological Significance
                                                    1. Influence on Spatial Summation
                                                      1. Factors Affecting Length Constant
                                                    2. Graded Potentials
                                                      1. General Characteristics
                                                        1. Amplitude Proportional to Stimulus
                                                          1. Decremental Conduction
                                                            1. Local Nature
                                                              1. Summation Properties
                                                              2. Temporal Summation
                                                                1. Repeated Stimuli Over Time
                                                                  1. Time Constant Effects
                                                                    1. Facilitation and Depression
                                                                    2. Spatial Summation
                                                                      1. Multiple Inputs at Different Locations
                                                                        1. Length Constant Effects
                                                                          1. Linear and Nonlinear Summation
                                                                          2. Types of Graded Potentials
                                                                            1. Excitatory Postsynaptic Potentials
                                                                              1. Depolarizing Nature
                                                                                1. Mechanisms of Generation
                                                                                  1. Cation Channel Opening
                                                                                    1. Effect on Action Potential Threshold
                                                                                    2. Inhibitory Postsynaptic Potentials
                                                                                      1. Hyperpolarizing or Shunting
                                                                                        1. Mechanisms of Generation
                                                                                          1. Chloride or Potassium Channel Opening
                                                                                            1. Effect on Excitability
                                                                                            2. Receptor Potentials
                                                                                              1. Sensory Transduction
                                                                                                1. Stimulus-Response Relationships
                                                                                                  1. Adaptation Properties
                                                                                                  2. Pacemaker Potentials
                                                                                                    1. Spontaneous Depolarization
                                                                                                      1. Rhythmic Activity Generation
                                                                                                        1. Ion Channel Mechanisms
                                                                                                        2. End-Plate Potentials
                                                                                                          1. Neuromuscular Junction
                                                                                                            1. Acetylcholine Receptor Activation
                                                                                                              1. Safety Factor for Transmission

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                                                                                                        2. The Resting Membrane Potential

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                                                                                                        4. The Action Potential