Neurophysiology: Myelination and Conduction of Action Potentials in Neurons - Prof. Connie, Study notes of Biology

Download Neurophysiology: Myelination and Conduction of Action Potentials in Neurons - Prof. Connie and more Study notes Biology in PDF only on Docsity! 24 January The rate of conduction of action potentials along a neuron will be increased by myelinating the neuron. Basic Principles Charged Particles Opposites attract – electrical gradient from – to + Energy must be used to separate charged particles of opposite signs Resting Membrane Potentials Property of all living cells Measure of the potential energy difference between the inside and outside of a cell membrane Neurons have resting membrane potential of -70 mV Electrical neutrality (small #) Inside and outside of cell is neutral Localized separation of charges Development and Maintenance Vm = 61 log PK [Kout ]+PNa [Naout ]+PCl[Cl¿ ] PK [K ¿ ]+PNa [Na¿ ]+PCl [Clout ] Na+/K+ pump Net movement Establish gradient Membrane potential (more negative on inside) Role of ATP Differences in Concentration K+ - greater inside Na+ - greater outside Cl- - greater outside A- - greater inside Differences in Permeability K+ ↑ 1 Na+ ↓ 0.04 Cl- ↑ 0.45 A- ↓ large protein molecule, does not pass through membrane Channels Leakage Gated Chemically (ligand) Voltage Driving Force Describes movement of ions across membrane Dependent on both electrical and chemical (concentration) gradients The cell membrane is relatively impermeable to sodium and anions Nerve and Muscle Cells Resting membrane potential: all living cells Action potentials Generate action potentials = excitability Propagate action potentials = conductivity