PHS 3507 Chapter Notes - Chapter 12: Automaticity, Bainbridge Reflex, Stroke Volume
25 Oct 2017
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Document Summary
Blood flows through over 60,000 miles of blood vessels. Similar arrangement of myofilaments as found in skeletal muscle. Join cardiocytes membranes via gap junctions, desmosomes: maintain structure. Heart functions like a single, massive cell (functional syncytium) Prolonged contraction time (10x longer than skeletal muscle). Pulmonary circuit- carries blood to and for the lungs. Systemic circuit- carries blood to and from the body. Blood flow alternates between the pulmonary and systemic circuits. Blood from head, neck, upper limbs and chest. Papillary muscles connect flaps to ventricular wall through chordae tendinae. Prevents valves from opening into atria (no backflow). Valve s close when ventricles contract to prevent blackflow. Continue to branch toward capillary beds of the lungs. Blood flows from respiratory capillaries into 4 pulmonary veins. Blood leaves the ventricle to the ascending aorta, through the aortic arch and into the descending aorta. Fibrous band connecting the aortic arch and pulmonary trunk. Right ventricle is pouch shaped, left is round.
