HLSC 1201U Lecture 30: Chapter 30 Notes
Document Summary
Constricts blood flow up the arm vein appears large for needles. Collection of mechanisms that influence the dynamic (active and changing) circulation of blood: differ from hemostasis stops blood from leaving blood vessel. Circulation control mechanisms must accomplish two functions (2): maintain circulation (only fluid that moves throughout the body, vary volume and distribution of blood circulated (collecting waste) Examples: eating a meal extra blood used to transfer nutrients, exercising increase flow to skeletal muscle and decrease flow in digestive tract. Conduction system structures are more highly specialized than ordinary cardiac muscle tissue and permit rapid conduction of an action potential through the heart. Specialized pacemaker cells in the sa node possess an intrinsic rhythm. Pacemaker cells: regulate heart beat rhythm, found in sinoatrial node ra , sympathetic n. s sends message. Function: send r/l atrium, or a to av node (in between ventricles) -> septum -> outside of heart. Depolarization: membrane potential gets + and atria contracts.