国外生理学与解剖学学习课件教学课件PPT.ppt

18-1,Anatomy&Physiology IIProfessor:Dr.Edward C.Deemer,Copyright(c)The McGraw-Hill Companies,Inc.Permission required for reproduction or display.,Dr.Edward Deemer APII,Missed ExamsDont.If by some miracle you get me to excuse the absence,the make up exam will be Essay Form.A death certificate would be an example of an valid excuse.AttendanceAttendance:Be on time.If you are not 5 minutes early:you are late!Attendance will be taken and recorded by me during the class period.Cell Phone PolicyTurn your cell phones OFF.Not to vibrate.,19-3,Circulatory System:The Heart,Circulatory system heart,blood vessels and bloodCardiovascular system heart,arteries,veins and capillariesTwo major divisions:Pulmonary circuit-right side of heartcarries blood to lungs for gas exchangeSystemic circuit-left side of heartsupplies blood to all organs of the body,19-4,Circulatory System:The Heart,Gross anatomy of the heartOverview of cardiovascular systemCardiac conduction system and cardiac muscleElectrical and contractile activity of heartBlood flow,heart sounds,and cardiac cycleCardiac output,19-5,Cardiovascular System Circuit,19-6,Position,Size,and Shape,Located in mediastinum,between lungsBase-broad superior portion of heartApex-inferior end,tilts to the left,tapers to point3.5 in.wide at base,5 in.from base to apex and 2.5 in.anterior to posterior;weighs 10 oz,19-7,Heart Position,19-8,Pericardium,Allows heart to beat without friction,room to expand and resists excessive expansionParietal pericardiumouter,tough,fibrous layer of CTPericardial cavity filled with pericardial fluidVisceral pericardium(a.k.a.epicardium of heart wall)inner,thin,smooth,moist serous layer covers heart surface,19-9,Pericardium and Heart Wall,Pericardial cavity contains 5-30 ml of pericardial fluid,19-10,Heart Wall,Epicardium(a.k.a.visceral pericardium)serous membrane covers heartMyocardiumthick muscular layerfibrous skeleton-network of collagenous and elastic fibersprovides structural support and attachment for cardiac muscleelectrical nonconductor,important in coordinating contractile activityEndocardium-smooth inner lining,19-11,Heart Chambers,4 chambersright and left atria two superior,posterior chambersreceive blood returning to heartright and left ventricles two inferior chamberspump blood into arteries,Atrioventricular sulcus-separates atria,ventriclesAnterior and posterior sulci-grooves separate ventricles(next slide),19-12,External Anatomy-Anterior,19-13,External Anatomy-Posterior,19-14,Heart Chambers-Internal,Interatrial septumwall that separates atriaPectinate musclesinternal ridges of myocardium in right atrium and both auriclesInterventricular septumwall that separates ventriclesTrabeculae carneaeinternal ridges in both ventricles,19-15,Internal Anatomy-Anterior,19-16,Heart Valves,Atrioventricular(AV)valvesright AV valve has 3 cusps(tricuspid valve)left AV valve has 2 cusps(mitral,bicuspid valve)chordae tendineae-cords connect AV valves to papillary muscles(on floor of ventricles)Semilunar valves-control flow into great arteriespulmonary:right ventricle into pulmonary trunkaortic:from left ventricle into aorta,19-17,Heart Valves,19-18,Heart Valves,19-19,AV Valve Mechanics,Ventricles relaxpressure dropssemilunar valves closeAV valves openblood flows from atria to ventriclesVentricles contractAV valves closepressure risessemilunar valves openblood flows into great vessels,19-20,Operation of Atrioventricular Valves,19-21,Operation of Semilunar Valves,19-22,Blood Flow Through Heart,19-23,Angina and Heart Attack,Angina pectoris partial obstruction of coronary blood flow can cause chest pain pain caused by ischemia,often activity dependent Myocardial infarction complete obstruction causes death of cardiac cells in affected areapain or pressure in chest that often radiates down left arm,19-24,Coronary Circulation,Left coronary artery(LCA)anterior interventricular branchsupplies blood to interventricular septum and anterior walls of ventriclescircumflex branchpasses around left side of heart in coronary sulcus,supplies left atrium and posterior wall of left ventricle Right coronary artery(RCA)right marginal branch supplies lateral R atrium and ventricleposterior interventricular branchsupplies posterior walls of ventricles,19-25,Venous Drainage of Heart,20%drains directly into right atrium and ventricle via thebesian veins80%returns to right atrium via:great cardiac vein blood from anterior interventricular sulcusmiddle cardiac vein from posterior sulcusleft marginal veincoronary sinus collects blood and empties into right atrium,19-26,Coronary Vessels-Anterior,19-27,Coronary Vessels-Posterior,19-28,Nerve Supply to Heart,Sympathetic nerves from upper thoracic spinal cord,through sympathetic chain to cardiac nervesdirectly to ventricular myocardiumcan raise heart rate to 230 bpmParasympathetic nervesright vagal nerve to SA nodeleft vagal nerve to AV nodevagal tone normally slows heart rate to 70-80 bpm,19-29,Cardiac Conduction System,Propertiesmyogenic-heartbeat originates within heartautorhythmic regular,spontaneous depolarizationComponentsnext slide,19-30,Cardiac Conduction System,SA node:pacemaker,initiates heartbeat,sets heart ratefibrous skeleton insulates atria from ventriclesAV node:electrical gateway to ventriclesAV bundle:pathway for signals from AV nodeRight and left bundle branches:divisions of AV bundle that enter interventricular septumPurkinje fibers:upward from apex spread throughout ventricular myocardium,19-31,Cardiac Conduction System,19-32,Metabolism of Cardiac Muscle,Aerobic respirationRich in myoglobin and glycogenLarge mitochondria Organic fuels:fatty acids,glucose,ketonesFatigue resistant,19-33,Cardiac Rhythm,Systole ventricular contractionDiastole-ventricular relaxationSinus rhythmset by SA node at 60 100 bpmadult at rest is 70 to 80 bpm(vagal inhibition)Premature ventricular contraction(PVC)caused by hypoxia,electrolyte imbalance,stimulants,stress,etc.,19-34,Cardiac Rhythm,Ectopic foci-region of spontaneous firing(not SA)nodal rhythm-set by AV node,40 to 50 bpm intrinsic ventricular rhythm-20 to 40 bpm Arrhythmia-abnormal cardiac rhythmheart block:failure of conduction systembundle branch blocktotal heart block(damage to AV node),19-35,Electrocardiogram(ECG),Composite of all action potentials of nodal and myocardial cells detected,amplified and recorded by electrodes on arms,legs and chest,19-36,ECG,P waveSA node fires,atrial depolarizationatrial systoleQRS complexventricular depolarization(atrial repolarization and diastole-signal obscured)ST segment-ventricular systoleT waveventricular repolarization,19-37,Normal Electrocardiogram(ECG),19-38,1)atrial depolarization begins2)atrial depolarization complete(atria contracted)3)ventricles begin to depolarize at apex;atria repolarize(atria relaxed)4)ventricular depolarization complete(ventricles contracted)5)ventricles begin to repolarize at apex6)ventricular repolarization complete(ventricles relaxed),Electrical Activity of Myocardium,19-39,Diagnostic Value of ECG,Invaluable for diagnosing abnormalities in conduction pathways,MI,heart enlargement and electrolyte and hormone imbalances,19-40,ECGs,Normal and Abnormal,19-41,ECGs,Abnormal,Extrasystole:note inverted QRS complex,misshapen QRS and T and absence of a P wave preceding this contraction.,19-42,ECGs,Abnormal,Arrhythmia:conduction failure at AV node,No pumping action occurs,19-43,Cardiac Cycle,One complete contraction and relaxation of all 4 chambers of the heartAtrial systole,Ventricle diastoleAtrial diastole,Ventricle systoleQuiescent period,19-44,Resistance opposes flowgreat vessels have positive blood pressureventricular pressure must rise above this resistance for blood to flow into great vessels,Principles of Pressure and Flow,Pressure causes a fluid to flow pressure gradient-pressure difference between two points,19-45,Heart Sounds,Auscultation-listening to sounds made by bodyFirst heart sound(S1),louder and longer“lubb”,occurs with closure of AV valvesSecond heart sound(S2),softer and sharper“dupp”occurs with closure of semilunar valves S3-rarely heard in people 30,19-46,Phases of Cardiac Cycle,Quiescent periodall chambers relaxedAV valves open and blood flowing into ventriclesAtrial systoleSA node fires,atria depolarizeP wave appears on ECGatria contract,force additional blood into ventriclesventricles now contain end-diastolic volume(EDV)of about 130 ml of blood,19-47,Isovolumetric Contraction of Ventricles,Atria repolarize and relaxVentricles depolarizeQRS complex appears in ECGVentricles contractRising pressure closes AV valves-heart sound S1 occursNo ejection of blood yet(no change in volume),19-48,Ventricular Ejection,Rising pressure opens semilunar valvesRapid ejection of bloodReduced ejection of blood(less pressure)Stroke volume:amount ejected,70 ml at restSV/EDV=ejection fraction,at rest 54%,during vigorous exercise as high as 90%,diseased heart 50%End-systolic volume:amount left in heart,19-49,Ventricles-Isovolumetric Relaxation,T wave appears in ECGVentricles repolarize and relax(begin to expand)Semilunar valves close(dicrotic notch of aortic press.curve)-heart sound S2 occursAV valves remain closedVentricles expand but do not fill(no change in volume),19-50,Ventricular Filling-3 phases,Rapid ventricular filling AV valves first openDiastasis sustained lower pressure,venous returnAtrial systole filling completed,19-51,Major Events of Cardiac Cycle,Quiescent periodVentricular fillingIsovolumetric contractionVentricular ejectionIsovolumetric relaxation,19-52,Events of the Cardiac Cycle,19-53,Rate of Cardiac Cycle,Atrial systole,0.1 secVentricular systole,0.3 secQuiescent period,0.4 secTotal 0.8 sec,heart rate 75 bpm,19-54,Ventricular Volume Changes at Rest,End-systolic volume(ESV)60 mlPassively added to ventricle during atrial diastole+30 mlAdded by atrial systole+40 mlEnd-diastolic volume(EDV)130 mlStroke volume(SV)ejected by ventricular systole-70 mlEnd-systolic volume(ESV)60 mlBoth ventricles must eject same amount of blood,19-55,Unbalanced Ventricular Output,19-56,Unbalanced Ventricular Output,19-57,Cardiac Output(CO),Amount ejected by ventricle in 1 minuteCardiac Output=Heart Rate x Stroke Volumeabout 4 to 6L/min at restvigorous exercise CO to 21 L/min for fit person and up to 35 L/min for world class athleteCardiac reserve:difference between a persons maximum and resting CO with fitness,with disease,19-58,Heart Rate,Pulse=surge of pressure in arteryinfants have HR of 120 bpm or moreyoung adult females avg.72-80 bpmyoung adult males avg.64 to 72 bpmHR rises again in the elderlyTachycardia:resting adult HR above 100stress,anxiety,drugs,heart disease or body temp.Bradycardia:resting adult HR 60in sleep and endurance trained athletes,19-59,Chronotropic Effects,Positive chronotropic agents HR Negative chronotropic agents HRCardiac center of medulla oblongataan autonomic control center with two neuronal pools:a cardioacceleratory center(sympathetic),and a cardioinhibitory center(parasympathetic),19-60,Sympathetic Nervous System,Cardioacceleratory centerstimulates sympathetic cardiac nerves to SA node,AV node and myocardiumthese nerves secrete norepinephrine,which binds to-adrenergic receptors in the heart(positive chronotropic effect)CO peaks at HR of 160 to 180 bpmSympathetic n.s.can HR up to 230 bpm,(limited by refractory period of SA node),but SV and CO(less filling time),19-61,Parasympathetic Nervous System,Cardioinhibitory center stimulates vagus nervesright vagus nerve-SA nodeleft vagus nerve-AV nodesecretes ACH(acetylcholine)which binds to muscarinic receptorsnodal cells hyperpolarized,HR slowsvagal tone:background firing rate holds HR to sinus rhythm of 70 to 80 bpmsevered vagus nerves(intrinsic rate-100bpm)maximum vagal stimulation HR as low as 20 bpm,19-62,Inputs to Cardiac Center,Higher brain centers affect HRcerebral cortex,limbic system,hypothalamus sensory or emotional stimuli(rollercoaster,IRS audit)Proprioceptors inform cardiac center about changes in activity,HR before metabolic demands ariseBaroreceptors signal cardiac centeraorta and internal carotid arteries pressure,signal rate drops,cardiac center HRif pressure,signal rate rises,cardiac center HR,19-63,Inputs to Cardiac Center,Chemoreceptorssensitive to blood pH,CO2 and oxygenaortic arch,carotid arteries and medulla oblongata primarily respiratory control,may influence HR CO2(hypercapnia)causes H+levels,may create acidosis(pH 7.35)Hypercapnia and acidosis stimulates cardiac center to HR,19-64,Chronotropic Chemicals,Affect heart rateNeurotransmitters-cAMP 2nd messengercatecholamines(NE and epinephrine)potent cardiac stimulantsDrugs caffeine inhibits cAMP breakdownnicotine stimulates catecholamine secretionHormonesTH adrenergic receptors in heart,sensitivity to sympathetic stimulation,HR,19-65,Stroke Volume(SV),Governed by three factors:preloadcontractility AfterloadCardiac Output=heart rate X stroke volume 75 bpm X 70 ml/beat=5250 ml/min(5.25 L)Total blood volume of body is 4-6 LTotal volume of blood passes through heart every minute.,Some Normal Values You Should Know“Hint,Hint!”,Blood Pressure:120/80Systolic Pressure:120Diastolic Pressure:80Heart Rate:Newborns:120 bpmAdult Females:72-80Adult Males:64-72Stroke Volume:70 ml/beatCardiac Output:5.25 L/minuteBlood Volume:4-6 L,19-66,19-67,Frank-Starling law of heart-SV EDVventricles eject as much blood as they receivemore they are stretched(preload)the harder they contractWhat happens if the heart does not eject as much as it recieves?,Some Cardiac Pathology You should know about“Hint Hint!”,Coronary ThrombosisThrombosis Clot lodging in a blood vesselA cause of Myocardial InfarctDVT Deep Vein ThrombosisMyocardial Infarct AKA heart attackVenous plaquing,Thrombi,Congestive Heart FailureInsufficient ventricular ejection of blood.Weakened heart muscle(infarct,High BP,defect)Right side vs.Left side,19-68,