PowerPoint PresentationAbout This ChapterTable 14.1 OVERVIEW OF THE CARDIOVASCULAR SYSTEM – The Primary FUNCTION of the Cardiovascular System TRANSPORTCardiovascular System ComponentsFigure 14.1Figure 14.2Pressure Differentials Drive Blood FlowFluid Flow through a Tube Depends on the Pressure Gradient – fluids flow from high to low pressure (pressure gradient)Figure 14.3c-1 ESSENTIALS – The Physics of Fluid FlowSlide 10Figure 14.3d ESSENTIALS – The Physics of Fluid FlowResistance Opposes FlowPoiseuille’s LawFigure 14.3e ESSENTIALS – The Physics of Fluid FlowSlide 15Figure 14.4Mean Arterial PressureFigure 14.5f ANATOMY SUMMARY – The HeartTable 14.2 The Heart and Major Blood VesselsFigure 14.5g ANATOMY SUMMARY – The HeartHeart Valves Ensure One-Way Flow in the HeartFigure 14.7a-b (1 of 6)Figure 14.7c-d (4 of 6)Cardiac MuscleFigure 14.5h ANATOMY SUMMARY – The HeartFigure 14.8Figure 14.9Cardiac Muscle Contraction Can Be GradedFigure 14.10Figure 14.11a (2 of 6)Figure 14.11b (3 of 6)Figure 14.12Figure 14.13Figure 14.14Electrical ConductionFigure 14.15a ESSENTIALS – The ElectrocardiogramFigure 14.15f ESSENTIALS – The ElectrocardiogramFigure 14.16Figure 14.15h ESSENTIALS – The ElectrocardiogramFigure 14.17aHeart SoundsSummary© 2013 Pearson Education, Inc.Cardiovascular PhysiologyChapter 14Ron Korthuis, [email protected] This Chapter•Overview of the cardiovascular system•Pressure, volume, flow, and resistance•Cardiac muscle and the heart•The heart as a pump© 2013 Pearson Education, Inc.Table 14.1 OVERVIEW OF THE CARDIOVASCULAR SYSTEM – The Primary FUNCTION of the Cardiovascular System TRANSPORTCardiovascular System Components•Heart–Septum divides left and right halves•Blood vessels–Arteries, arterioles, capillaries, postcapillary venules, veins–Pulmonary and systemic circulation•Blood–Cells (white & red) and plasma© 2013 Pearson Education, Inc.Figure 14.1THE CARDIOVASCULAR SYSTEMThe cardiovascular system is a closed loop.The heart is a pump that circulates bloodthrough the system. Arteries take bloodaway from the heart, and veins carryblood back to the heart.Veins Capillaries ArteriesHead andBrainArmsLungsSuperior vena cavaPulmonaryarteriesRightatriumPulmonaryveinsAscending arteriesAbdominal aortaAortaLeft atriumCoronaryarteriesLeft ventricleHeartRightventricleInferior vena cavaTrunkHepatic arteryHepatic portal veinHepaticveinLiverDigestivetractRenalarteriesKidneysRenalveinsAscending veinsVenous valvePelvis andLegsDescending arteriesFIGURE QUESTIONA portal system is two capillary bedsjoined in series. Identify the twoportal systems shown in this figure.Figure 14.2Blood Flows Down a Pressure Gradient.The mean blood pressure of the systemic circulation rangesfrom a high of 93 mm Hg (millimeters of mercury) in the aortato a low of a few mm Hg in the venae cavae.Mean systemic blood pressure(mm Hg)100806040200AortaArteriesArteriolesCapillariesVenulesVeinsVenae cavaePRESSURE, VOLUME, FLOW, AND RESISTANCEPressure Differentials Drive Blood Flow•Pressure created by contracting muscles is transferred to blood•Driving pressure is created by the ventricles•If blood vessels dilate, blood pressure decreases•If blood vessels constrict, blood pressure increases•Volume changes affect blood pressure in cardiovascular system© 2013 Pearson Education, Inc.Fluid Flow through a Tube Depends on the Pressure Gradient – fluids flow from high to low pressure (pressure gradient)•Flow through a tube is directly proportional to the pressure gradient–Flow  P–The higher the pressure gradient, the greater the fluid flow© 2013 Pearson Education, Inc.Figure 14.3c-1 ESSENTIALS – The Physics of Fluid FlowFluid flows only if there is a positive pressuregradient ( P).Higher P Flow Lower PFlowP1P2P1  P2   PFigure 14.3c-1 ESSENTIALS – The Physics of Fluid FlowThis tube has no pressure gradient, so no flow.100 mm Hg 100 mm Hg P  0, so no flowFluid flows only if there is a positive pressuregradient ( P).Figure 14.3d ESSENTIALS – The Physics of Fluid FlowFluid flow through a tube depends onthe pressure gradient.Flow depends on the pressure gradient ( P),not on the absolute pressure (P).  P is equalin these tubes so flow is the same. P  100  75  25 mm Hg P  40  15  25 mm Hg100 mm Hg 75 mm Hg40 mm Hg 15 mm HgFlowFlowflow isequal•Flow through a tube is inversely proportional to resistance–Flow  1/R–If resistance increases, flow decreases–If resistance decreases, flow increases© 2013 Pearson Education, Inc.Resistance Opposes Flow•R  8L/r4 or R  L/r4 •Resistance is proportional to length (L) of the tube (blood vessel)–Resistance increases as length increases•Resistance is proportional to viscosity (), or thickness, of the fluid (blood)–Resistance increases as viscosity increases•Resistance is inversely proportional to tube radius to the fourth power–Resistance decreases as radius increases © 2013 Pearson Education, Inc.Poiseuille’s LawFigure 14.3e ESSENTIALS – The Physics of Fluid FlowAs the radius of a tube decreases, the resistance to flow increases.Radius of A  1Volume of A  1 Volume of B  16Radius of B  2FIGURE QUESTIONIf the radius of A changes to 3, the flow through Awill be about ______ times the flow through B.Resistance  Flow Tube ATube ATube BTube BR R  1Flow Flow  1Flow Flow  16R R 1142411161radius41resistance111116•Small change in radius has a large effect on resistance to blood flow–Vasoconstriction is a decrease in blood vessel diameter/radius and decreases blood flow–Vasodilation is an increase in blood vessel diameter/radius and increases blood flow•Flow = P/R–Flow of blood in the cardiovascular system is –Directly proportional to the pressure gradient–Inversely proportional to the resistance to flow© 2013 Pearson Education, Inc.Resistance Opposes FlowFigure 14.4Flow rate is not the same as velocity of flow.The narrower the vessel, the faster the velocity of flow.If the cross-sectional area of thispipe is 3 cm2, what is the velocityof the flow?A  12 cm2A  1 cm212 cm3FlowFlow rate (Q)  12 cm3/minVelocity (v) XYv  12 cm/min v  1 cm/minv v Flow rate (Q)Cross-sectional area (A)12 cm3/min1 cm212 cm3/min12 cm2At point X At point YFIGURE QUESTIONMean Arterial Pressure•Mean arterial pressure = cardiac output 