NEU 301 Study Guide - Midterm Guide: Axon Hillock, Axoplasmic Transport, Dendritic Spine
Document Summary
Anterograde transport is transport of molecules/organelles outward away from the cell body. Ion channels (nonpolar and polar ends) move faster than ion pumps and don"t need atp to function. Inside of the membrane becomes positively charged for a small amount of time. First rising phase: rapid depolarization then falling phase (repolarization) and finally undershoot or hyperpolarization. Action potentials are caused by depolarization of the membrane beyond threshold. Firing frequency represents the magnitude of the depolarizing current. Once an action potential is initiated there must be a time lapse before another one can go, this is absolute refractory period. The threshold is momentarily increased after the first one and this phase is the relative refractory period. Depolarization is caused by an influx of sodium ions and repolarization is caused by an efflux of potassium ions. Action potentials can occur in muscle cells, and neurons and others.
