医学英语心脏.ppt

SUMC 2011-2012Students copyThe cardiovascular systemnWhat is the circulatory system?nWhat does the CV system do?nInternal and external anatomynCardiac cyclenHeart soundsnConductive system of the heartnBlood vesselsnDiseases of the CVSThe Heart and blood vessels together make up the cardiovascular System.nCirculate blood throughout entire body forTransport of oxygen to cellsTransport of CO2 away from cellsTransport of nutrients(glucose)to cellsMovement of immune system components(cells,antibodies)Transport of endocrine gland secretionsThe Heart:location in thoraxThe Heart:location in thoraxnOblique PositionnApex=Left of Midline(5th ICS),Anterior to rest of heartnBase(posterior surface)sits on vertebral columnnSuperior Right=3rd Costal Cartilage,1”right midsternumnSuperior Left=2nd Costal Cartilage,1”left midsternumnInferior Right=6th Costal Cartilage,1”right midsternumnInferior Left=5th Intercostal Space at Midclavicular lineSerous membraneContinuous withblood vesselsThe Heart:muscle layers and coveringsThe Heart:muscle layers and coveringsConnective tissEndothiliumExternal Heart AnatomyPage 44The Heart:ChambersLungsBody cellsOur circulatory system is a double circulatory system.This means it has two parts parts.the right side of the system deals with deoxygenated blood.the left side of the system deals with oxygenated blood.CirculationCoronary circulation the circulation of blood within the heart.Pulmonary circulation the flow of blood between the heart and lungs.Systemic circulation the flow of blood between the heart and the cells of the body.The Heart:ValvesBicuspid(mitral)Tricuspid (AV)PulmonaryAortic (SL)How does the Heart work?blood from the bodyblood from the lungsThe heart beat begins when theheart muscles relax and bloodflows into the atria.STEP ONEThe atria then contract andthe valves open to allow bloodinto the ventricles.How does the Heart work?STEP TWOHow does the Heart work?The valves close to stop bloodflowing backwards.The ventricles contract forcing the blood to leave the heart.At the same time,the atria arerelaxing and once again filling withblood.The cycle then repeats itself.STEP THREEFilling of Heart Chambers the Cardiac CycleCopyright 2003 Pearson Education,Inc.publishing as Benjamin CummingsThe Heart:Cardiac OutputCopyright 2003 Pearson Education,Inc.publishing as Benjamin CummingsCardiac output(CO)total vent blood/minAmount of blood pumped by each side of the heart in one minuteCO=(heart rate HR)x(stroke volume SV)Stroke volumeVolume of blood pumped by each ventricle in one contractionS1-What is it?closing of the bicuspid and tricuspid valves.(closure of the AV valves)The Pulmonic and Aortic valves are openingand blood is being forced into the arteriesS2-What is it?The sounds are because of the closing of the Pulmonic and Aortic valves (closure of the semilunar valves)Conductive SystemAction potential-electrical impulse causing the contraction of heart muscle cellsThe SA node,or pacemaker,initiates the heartbeat and causes the atria to contract on average every 0.85 seconds.The AV node conveys the stimulus and initiates contraction of the ventricles.The signal for the ventricles to contract travels from the AV node through the atrioventricular bundle to the smaller Purkinje fibers.ElectrocardiogramnAn electrocardiogram(ECG)is a recording of the electrical changes that occur in the myocardium during a cardiac cycle.nThe P wave occurs just prior to atrial contraction;the QRS complex occurs just prior to ventricular contraction;and the T wave occurs when the ventricles are recovering from contraction.The Vascular SystemCopyright 2003 Pearson Education,Inc.publishing as Benjamin CummingsBlood Vessels:AnatomyThree layers(tunics)Tunic intimaEndotheliumTunic mediaSmooth muscleTunic externaMostly fibrous connective tissueConductive SystemCopyright 2003 Pearson Education,Inc.publishing as Benjamin CummingsFigure 11.5nTunica externaOutermost layerelastin and collagenStrengthens,AnchorsnTunica mediaMiddle layerCircular Smooth MuscleVaso-constriction/dilationnTunica intimaInnermost layerEndotheliumMinimize frictionnLumenArtery/Vein differences（归纳：dtwlv)Arteries(aa.)Veins(vv.)Direction of flowBlood Away from HeartBlood to HeartPressureHigherLowerWallsTHICKER:Tunica media thicker than tunica externaTHINNER:Tunica externa thicker than tunica mediaLumenSmallerLargerValvesNo valvesValves Coronary artery circulationPulsePulse pressure wave of bloodMonitored at“pressure points”where pulse is easily palpatedMeasuring Arterial Blood PressureCardiovascular DiseasesnCardiovascular diseases include those that affect the heart and those that affect the peripheral vascular system.nThe heart and blood vessels may be primarily attacked by these diseases or they may be secondarily affected as a consequence of another disease.Risk Factors for Cardiovascular Disease(sdosp)nSmokingnDiabetesnObesity nStressnPhysical InactivitynHigh Blood Pressure 140(systolic)/90(diastolic)Cardiovascular DiseasesnCoronary Artery Disease(CAD)nEndocarditisnPericarditisnRheumatic Heart DiseasenHypertensionnCardiac ArrhythmianCongestive Heart Failure(CHF)nStrokenArteriosclerosisnAneurysm