Psychology 1000 Lecture Notes - Lecture 2: Axon Hillock, Membrane Technology, Reflex Arc

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

Document Summary

Extracellular fluid protected by cell membrane (partially permeable) Action potential created (40 mv) from the resting potential (-70 mv) due to the + on the outside and charges on the inner side of the cellular membrane. During this process, na becomes depolarized and more na inflow. During depolarization, the membrane potential becomes -55 mv and all hell breaks loose and everything goes crazy. After the membrane potential becomes +40 mv, the membrane becomes repolarized by potassium ions" outflow. This is the absolute refractory period, where it is closed to all membrane processes. After the absolute refractory period, there is a relative refractory period. During depolarization, the membrane potential may go below -70 mv, in which case, it becomes hyperpolarized and then slowly drifts back to the resting potential. Only axons have action potential, starting from the axon hillock. Height of spike fixed: neurons have different thresholds, strong stimulus more neurons, intensity directly proportional to frequency of firing.