PSYCH 212 Lecture Notes - Lecture 5: Axon Hillock, Threshold Voltage, Membrane Potential

• School: Northwestern University
• Department: Psychology
• Course: PSYCH 212
• Professor: Robin Nusslock

Document Summary

Constitutively open channels stay open all the time have selective permeability. Open potassium ion (k+) channels are central to neural signaling. Gated ion channels open and close in response to signals gated sodium ion (na+) channels are central to neural signaling. Ion pumps actively use energy to transport ions across the membrane sodium-potassium pumps are central to neural signaling. Most open ion channels in neurons only allow potassium ions (k+) to cross membrane selective permeability to k+ Sodium-potassium pump pumps three sodium ions (na+) out for every two potassium ions (k+) pumped in. Electrochemical forces act on potassium ions to help establish resting potential diffusion - particles move from areas of high concentration to areas of low concentration. Semipermeable membranes permit some substances to move through electrostatic pressure - ions ow towards oppositely charged areas, along a voltage gradient. The sodium-potassium pumps continuously to pull k+ ions in.