BIOL 1080 Lecture Notes - Lecture 11: Great Saphenous Vein, Ulnar Artery, Heart Valve
Document Summary
What makes it diff. from cardiac muscle neural input: involuntary, autonomic neural conduction: gap junctions v fast, contract as a unit (syncytium) ie no fibre re- cruitment like skeletal muscle. Metabolism: v high oxidative capacity (lots of mitochon) fatigue resistance. Lub sound = av heart valves closing, dub = semilunar valvles atrioventricular valve (av) located bw each atrium & ventricle preventing backflow; tri- cuspid = right, mitral = left semilunar valves. Artificial valve issues: durability, supposed to last 20+yrs; clot formation, req. consistent anticoagulant therapy; get stuck; resistance to flow, vulnerability to backflow & regurgit- ation alternative = biological valves, usually from pigs (rew immunosuppression) Most serious are fibrillations, when cells depolarize independently. Trivia athletes often have lower resting hr, bc of sympathetic nrvous system, but not always lowest = 28 bpm can reach 400bpm during tachycardia across species: smalle hearts = faster beatn.
