BIOL 208 Chapter Notes - Chapter 18 - 21: Arteriole, Atrioventricular Node, Hyperkalemia
12 Apr 2017
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Document Summary
Arrhythmias - defects intrinsic conduction system, irregular heart beats. Fibrillation - out of phase contraction, control of heart rhythm is released from sa node. Junctional rhythm - pace set by av node, between 40 and 60 beats/min. Extrasystole - contraction before sa node has a contraction. Heart block - signals can"t get through and ventricles can"t maintain appropriate beat. Hypocalcemia - decreased calcium blood levels and heart rate. Hypercalcemia - above normal blood levels and increased heart rate. High calcium levels can cause fatal arrhythmias. Hyperkalemia - depolarizes resting potential - heart block and cardiac arrest. Caused by increased temperature, stress, drugs, heart disease. Bradycardia - slow heart rate (less than 60/min) Caused by decreased temperature, drugs, parasympathetic nervous activity. Heart hypertrophies and sv increases = low heart rate and same cardiac output. Warning for brain bleeding after head injury: 701 table 19. 1 - structure of arteries, veins and capillaries. Elastic artery - diameter - 1. 5 cm.
