Muscular System

The normal anatomy and physiology of a muscle determines its capability of formulating a contraction. The contraction of a muscle is dependent on the ability of a neuron to become excited through a process that includes a concentrated flow of sodium (Na+), potassium (K+), and calcium (Ca+) through the neuron and eventually into the muscle cell (Tortora & Derrickson, 2011). A neuron begins its resting membrane potential at -70mv. In order for an action potential to occur, which is the event that will precede the muscle contraction, the membrane must first depolarize and become more positive, reaching -55mv. Once -55mv is reached, the membrane is said to be at the threshold potential, the voltage by which most Na+ channels in the cell membrane would open. After the first Na+ channel opens, the cell becomes even more depolarized and Na+ ions move into the cell (Martini, Nath, & Bartholomew,...
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