BIOL 3P34 Lecture Notes - Lecture 12: Cytoplasm, Action Potential, Extracellular Fluid

• School: Brock University
• Department: Biological Sciences
• Course: BIOL 3P34
• Professor: Gaynor E Spencer

Document Summary

Membrane time constant : time it takes to reach 63% of its final value. Time course of a potential signal: function of t = 10 ms. If potentials overlap in time they add together. Same train of action potentials in both traces represents identical synaptic input. Longer : longer the duration of a synaptic potential. Individual potentials may be too small to generate a threshold potential for ap generation. A longer has a more chance of incoming potentials to be added: membrane resistance, cytoplasmic resistance. Voltage signal decreases in amplitude with distance from the site of initiation. Internal resistance (ri) (or axial resistance, ra) (unit: / cm) It will decay with distance depending on the length constant or ri. X : distance from site of injection (current source) : membrane potential at distance x from current source l = distance along neurite to site where. 37% (or 1 / e) of its original value.