PSYCH 3313 Lecture Notes - Lecture 5: Resting Potential, Potassium Channel, Ion Transporter
14 Sep 2016
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Tools for measuring a neuron"s electrical activity: oscilloscope, microelectrodes. Giant axon of the squid: much larger in diameter than human axons. Squid: up to 1 millimeter (1000x humans: used by hodgkin and huxley in the 1930s and 1940s. Hydrophilic: likes to be around other water molecules. Extracellular vs. intracellular fluid: extracellular = more sodium and chloride ions (more like concentration of seawater) B: patterns roughly the same in squids and humans. More ions in squid b/c lives in seawater. Diffusion: molecules move from areas of high concentration to areas of low concentration. Psych 3313: like charges repel, electrical gradient. Concentration gradients and voltage gradients: concentration = diffuses from initial point of contact until it is equally distributed throughout, voltage = positive and negative ions flow down their electrostatic gradients until positive and negative charges are equal everywhere. Equilibrium: balance occurs when the concentration gradient = voltage gradient, barriers. Over time ions disperse through section but cannot always cross: overcoming barriers.
