PSYC 271 Chapter Notes - Chapter 1-3: Resting Potential, Membrane Potential, Axon Terminal

• School: Queen's University
• Department: Psychology
• Course: PSYC 271
• Professor: Tyson Baker

Document Summary

Depolarization = positive, more k+ ow outside, na+ in ux. Hyper polarization = negative, more k+ ow in, na+ ef ux. Sodium ion channels in resting neurones are closed. Potassium channels are open in resting neurons are open (only few k+ exit bc they are largely held inside the negative resting membrane potential) Sodium-potassium pumps: ion transporter than actively exchanges 3 na+ ions inside the neurons for 2 k+ ions outside. Step 2: understand how postsynaptic potentials create action potentials. Epsp: postsynaptic depolarizations, increase likelihood that ap is generated. Ipsp: postsynaptic hyper polarization, decrease likelihood that ap is generated. Graded responses - responses whose magnitude is proportional to the magnitude of the stimuli that elicit them. Threshold of excitation: epsp depolarization necessary for action potential - 65mv. Action potential: massive momentary reversal of a neuron"s membrane potential from -70mv to +50 mv - lasts 1 millisecond.