PSIO 420 Lecture Notes - Carotid Body, Isometric Exercise, Vasodilation
20 Jan 2014
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Document Summary
60,000 miles of blood vessels: heart develops autorhythmicity after gestation. 25% mitochondrial density - therefore the heart is continually generating atp so that it does not have to use anaerobic respiration. Compare to skeleton muscle which only has 2% mitochondria. Intercalated disks allow for the heart as a whole to function as one big pump per contraction: gap junctions - allow for a rapid dispersal of action potentials that generate a contraction, desmosomes - physical connection between fibers. Sa node (cardiac myocytes: sets autorythmicity of heart. Important in generating hr: affected by autonomic nervous system. Sympathetic nervous system increases hr, contractility with an increase in. Parasympathetic nervous system affects depolarization, by releasing. Acetylcholine which reduces camp and ultimately reduces hr - example of rest. Av node (atrioventricular: slows conduction of electrical signals before the spreading the signals to the ventricles. Bundle of his: electrical conduit between atria and ventricles.
