Psychology 1000 Lecture Notes - Reflex Arc

• School: Western University
• Department: Psychology
• Course: Psychology 1000
• Professor: Dr.Mike

Document Summary

Classify by function: sensory neurons afferent, motor neurons efferent (terminate in effectors, e. g. muscles and glands) Semi permeable cell membrane of neuron is filled with charged particles (na+, k+, cl-, (a- represents a protein)) Extra cellular fluid is also filled with charged particles. Na+ outside of the cell outnumbers the amount of na+ inside by a factor of 10 to 1. Cell membrane becomes changed outside is positive, inside is negative. Stimulation allows for depolarization (na+ flows into the neuron) 55 is the threshold; na+ flow greatly increases. Once the potential reaches +40, repolarisation occurs (k+ outflow) When the neuron potential is below the resting potential (-70), it is hyperpolarized. Whole action potential occurs in 7 milliseconds. Absolute refractory period refers to the drop from +40 to beneath -70 potential (neuron can"t fire at this point) Relative refractory period is the recovery phase from below -70 back to resting potential (neuron can still fire if the stimuli is especially large)