Physiology 3140A Chapter Notes -Reversal Potential, Current Clamp, Goldman Equation

• School: Western University
• Department: Physiology
• Course: Physiology 3140A
• Professor: Donglin Bai

Document Summary

Take-home messages for dr. bai"s section on 3140a midterm. Introduction: electrical current in the body is carried by positive and negative ions, rather than electrons. Tetradotoxin (ttx) blocks opening of na+ voltage-gated channel. Lecture 6: passive membrane properties: a passive membrane is one that does not generate voltage-dependent responses like action potentials and a passive membrane response is at voltages below threshold of an. In the passive injection of positive current, a positive ion travelling to the cytoplasmic face meets with a negative charge to neutralize and effectively discharges the membrane (depolarization that changes the voltage). Lecture 7: action potential i: sub-threshold potentials are local, decay rapidly with distance, are graded by magnitude, have no refractory period, and can be summed algebraically (all properties of a linear stimulus). Increasing current stimulus below threshold generates a sub-threshold potential of greater amplitude until threshold is reached, resulting in an action potential.