HTHSCI 1H06 Chapter Notes - Chapter 12: Membrane Potential, Cell Membrane, Motor Neuron

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 1H06
• Professor: Peter Helli

Document Summary

Short distance communication only: action potentials. The production potentials depends two basic features of the plasma membrane: the existence of a resting membrane potential, the presence of specific types of ion channels. Ion channels allow specific ions to move across the plasma membrane, down their electrochemical gradient: chemical, electrical high to low concentration positive to negative. Ion channels open and close due to the presence of gates. Four types: leak, ligand-gated, mechanically-gated, voltage-gated. Leak channels randomly alternate between open and closed positions. Typically, plasma membranes have many more k+ leak channels than na: potassium ion channels are leakier, membrane permeability to k+ is higher found in nearly all cells and all parts of the neuron. Mechanically-gated channel opens or closes in response to mechanical stimulation: vibration, touch, pressure, or tissue stretching example: in receptors that monitor stretching of internal organs in touch receptors and pressure receptors in the skin.