PSYC1004 Lecture Notes - Lecture 12: Myelin, Depolarization, Resting Potential

• School: ANU
• Department: Psychology
• Course: PSYC1004
• Professor: Professor Michael Platow

Document Summary

There are three main types of neurons: sensory neurons: transmits information from sensory receptors to the cns, motor neurons: transmits signals from the central nervous system to effector cells/organs. Interneurons: connect with other neurons to help transmit messages. Electrical impulses - information transition: neurons transmit information in the form of an electrical impulse, action potential is the electrochemical polarisation and depolarisation that travels across the membrane of a neuron in response to stimulation. This means that excess na+ build up outside the and potassium ions inside. Inside the cell is now positively charged relative to the outside: at the same time, k+ begins to leave, this starts the recovery process, the na+/k+ pump mechanism restores polarisation by pumping na+ out and k+ in. Thus depolarisation moves progressively: the myelin sheath that covers axons causes the message to travel quicker. This is because depolarisation only occurs in each node of ranvier.