Chapter 38: Circulation and PerfusionCirculation refers to flow of blood throughout theheart and blood vessels.Perfusion describes blood flow to a capillary bed toprovide nutrients and oxygen to tissues and organs.Although the distinction between these two concepts issubtle, they go hand in hand in explaining how a healthycirculatory system contributes to healthy functioning of everyorgan in the body.pg 1438-1452 (stop at prevent clotformation)
Helpful website for understandingcardiovascular anatomy andphysiologyv/health/dci/Diseases/hhw/hhw_whatis.htmlFollow the link and click on:What Is ...AnatomyContractionCirculationElectrical System•Meet the Heart—Khan Academy•high-school-biology/hs-human-body-systems/hs-the-circulatory-and-respiratory-systems/v/meet-the-heart•Blood Flow thru the Heart—KhanAcademy•health-and-medicine/circulatory-system/circulatory-system-introduction/v/flow-through-the-heart
Structures of the CardiovascularSystemHeart•Cardiac Cycle: simultaneouscontraction of the twoatria, followed a fraction ofa second later by thesimultaneous contractionof the ventricles.•Electrical Conduction:electrical activity thatinitiates contraction of themyocardiumFigure 38-1The atria receive blood into the heart; theventricles pump blood out of the heart. Valvesbetween the chambers allow blood to flow inone direction from one chamber to anotherwithout backflow.
Structures of the CardiovascularSystem (cont’d)Cardiac Cycle•Sinoatrial (SA) node:pacemaker of the heart•Atrioventricular (AV)node: electrical activitypasses through the AVnode into the left andright bundles of HIS andinto Purkinje fibers to theventriclesFigure 38-2Conduction pathway of the heart.Anterior view of the interior of theheart. The electrocardiogram tracingis one of a normal heartbeat.
Structures of the CardiovascularSystem (cont’d)Systemic and PulmonaryBlood Vessels•Arteries:oxygenated bloodto the tissues•Arterioles•Capillaries•Veins and venules:•Deoxygenated blood backto heart/lungsFigure 38-1The atria receive blood into the heart; theventricles pump blood out of the heart.Valves between the chambers allow bloodto flow in one direction from one chamberto another without backflow.
Structures of the Cardiovascular System(cont’d)•Heart, blood vessels, red blood cells•Hemoglobin: carries oxygen•The vascular system is composed of three types of vessels: arteries andarterioles, veins, and capillaries.•Arteries•Oxygenated blood to tissues. Arteries have thick, elastic walls that allow them tostretch during cardiac contraction (systole)and to recoil when the heart relaxes(diastole).