PHGY 209 Lecture Notes - Lecture 5: Latrodectus, Postsynaptic Density, Barbiturate

• School: McGill University
• Department: Physiology
• Course: PHGY 209
• Professor: Ann Wechsler

Document Summary

Neurons: cell body/soma: where cell metabolism taking place, what keeps neuron alive, where nucleus located, dendrites: extremely complex, axons can extend over very long distances, propagate information. Informational polarized, always flows in same direction; dendrites - cell body - axon. Equilibrium potential: potassium flows out which creates negative charge, and the rate at which flows back in = rate at which flows out so - charge maintained, nernst equation not tested. K+ in (against concentration gradient) to maintain ion gradients. Ions found in every type of cell in body, even more important in neurons (specialized: axons are specialized to propagate action potentials (brief electrical impulses) Voltage-gated potassium channels: actual flow of potassium ions starts at peak of potassium ions, but channels start opening almost from the start, potassium permeability larger during action potential than resting, accelerates repolarizing phase. Signal intensity: touch sensitive action: intensity related to frequency of action potential.