PHYL 1010X Chapter Notes -Microglia, Oligodendrocyte, Astrocyte

• School: Dalhousie University
• Department: Physiology
• Course: PHYL 1010X
• Professor: n/a

Document Summary

+ move across the membrane during action potentials: membrane depolarizes to threshold, voltage gated na+ channels open (cid:224) rapid na + entry depolarizes the cell, k+ channels begin to open slowly, na+ channels close & slower k+ channels open, k+ moves from cell to ecf (cid:224) hyperpolarizes the cell, voltage gated k+ channels close (cid:224) less k + leaks out of the cell, cell returns to resting ion permeability & resting membrane potential. Action potential propagation (conduction): the movement of an action potential through the axon at high speed, graded potential above threshold reaches the trigger zone, voltage gated na+ channels open (cid:224) na + enters the axon, positive charge flows into the adjacent sections of the axon by local current flow, local current flow from active region causes new sections of the membrane to depolarize, refractory period prevents backward conduction, loss of k+ from the cytoplasm repolarizes the membrane.