Physiology 2130 Study Guide - Midterm Guide: Aortic Valve, Heart Valve, Qrs Complex
13 Apr 2018
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Tbv: 5/6l: heart/pulmonary cir=15, systemic arteries/arterioles=10, systematic capillaries=5, systematic viens/venules=70% *blood volume not equally distributed b/w 2 systems. Myocardial cells: self-excitatory system for heart to generate impulses and a transmission system for rapid conduction of impulses throughout heart. 2 types: contractile cells: fibers with similar features to skeletal muscle, specialized nodal & conducting cells, nodal cells, sinoatrial (sa) node, atrioventricular (av) node, conducting cells, bundle of his, purkinje fibers. Similar: striated, contain similar contractile proteins (actin/myosin0, ca++ release from sr triggers contraction. Differences: size: short/branched, 1/3 occupied w/mitchondira, need a lot of o2 for mitcho extract 80% o2 from blood, join by intercalculated discs that contain gap junctions. Allow movement of ionic current (aps) b/w cells. Sa node (self-excitability: self-excitatory impulse which trigger heart beat originate in sa (upper posterior wall of right atrium, a: (cid:272)o(cid:374)trols rate of heart (cid:271)eat (cid:862)pa(cid:272)e(cid:373)aker(cid:863) Cause self-excitability: greater na and ca permeability, k permeability decrease (less k allow to leave) during diastole.
