Physiology 3140A Lecture Notes - Lecture 8: Electroencephalography, Ampa Receptor, Lipid Bilayer
24 Dec 2016
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Document Summary
Electrical currents are used by brain cells and muscles for generating signals for communications. We make use of these currents for medical diagnostic tests. Electric currents from the heart are measured by attaching wires to the body, and measured as an electrocardiogram. Electroencephalogram records brain electrical activities from different electrodes placed on the scalp. Electrical currents are used to stimulate muscle contraction and nerve excitation, and to restart the heart beat. The direction of an electric current is defined to be the movement of positive charges. Positive charge moves from a point of high (electric) potential to a point of low potential, and the larger the potential (voltage) difference, the larger is the current. The current also depends on the medium that carries the current. A small diameter cable offers higher resistance than a large-diameter cable. In biological tissues, electrical activities are carried by ions (not electrons)
