ANP 1106 Study Guide - Final Guide: Alpha Motor Neuron, Motor Neuron, Skeletal Muscle

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1106
• Professor: All

Document Summary

Physiology of the nervous system lecture 1. Voltage - a charge separation energy measured between two points, and is known as the potential difference. Biological potentials have voltages ranging between -90 to +55 mv. Current flow of charge from a to b as a result of potential. Ohms law: current (i) = voltage (v)/resistance (r) Only k+ potential contributes to membrane potential. Voltage-gated ion channels the basis of the ability of action potentials to be carried down axons. Strength does not decrease with distance because it is constantly being regenerated. In myelinated axons, action potentials can only occur at the nodes of ranvier: current spreads between nodes of ranvier by graded potential. Myelin in the cns is formed from oligodendrocytes. Myelin in the pns is formed from schwann cells. Dendrites ligand-gated channels are activated by neurotransmitters. Axons voltage-gated channels are activated by depolarization. Synaptic terminals voltage-gated calcium channels open to allow neurotransmitter released. Gaba opens chloride channels and is inhibitory.