Cardiovascular Anatomy and Physiology Notes- Diagrams & Illustrations - Osmosis

ARDIOVASCULAR ANATOMY & PHYSIOLOG CARDIOVASCULAR ANATOMY & PHYSIOLOGY -~ osms.it/cardiovascular-anatomy-physiology =~ CARDIOVASCULAR SYSTEM = Cardia-, cardi-, cardio- = Heart, which pumps blood = Vascular: blood vessels (carry blood to body, return it to heart) = Delivers oxygen, nutrients to organs, tissues = Removes waste (carbon dioxide, other cellular respiration by-products) from organs, tissues MORPHOLOGY = Size: about size of person’s first (correlated with person’s size) = Shape: blunt cone-shaped = Position: slightly shifted to left side = Location o Lies in mediastinum in thoracic cavity MEDIASTINUM * MIDDLE of THORAX DIAPHRAGM VERTEBRAL COLUMN = Sits on top of diaphragm (main breathing muscle) = Behind sternum (breast bone) = |n front of vertebral column o Between lungs = Enclosed, protected by ribs o Right, left sides separated by muscular septum Heart wall layers = Epicardium: covers surface of heart, great vessels (AKA visceral pericardium) = Myocardium: muscular middle layer = Cardiac muscle cells: striated branching cells with many mitochondria, intercalated disks for synchronous contraction = Cardiac myocytes: striated, branching cells with fibrous cardiac skeleton Figure 1441 Heart location relative to other thoracic structures. OSMOSIS.ORG NOTES 83

84 OSMOSIS.ORG (supports muscle tissue, crisscrossing = Serous pericardium: simple squamous connective tissue collagen fibers); epithelium layer coronary vessels (lie on outside of heart, = Parietal pericardium: lines fibrous penetrate into myocardium to bring pericardium blood to that layer) = Visceral pericardium (epicardium): = Endocardium: innermost layer covers outer surface of heart = Made of thin epithelial layer, underlying = Cells of parietal, visceral pericardium connective tissue secrete protein-rich fluid (pericardial = Lines heart chamber, valve fluid) — fills space between layers = Pericardium: double-layered sac (lubricant for heart, prevents friction) surrounding heart = Fibrous pericardium: outer layer; tough fibrous connective tissue anchors heart within mediastinum CORONARY VESSELS 3. ENDOCARDIUM 1. EPICARDIUM * ENDOTliEUUM ’L HA |1 CARDIAC | , I [ | MUSCLE CELL Il 1L — CONNECTIVE %\ TISSVE USRI | x COLLAGEN I J * SUPPORTS MUSCLE (. 3. MYOCARDIVM Figure 14.2 Heart wall layers, from superficial to deep. SEROVS PERICARDIUM SAC of FLUID PARIETAL LAYER FIBROUS PERICARDIUM PROTEIN-RICH FLVID SURFACE of VISCERAL HEART LAYER , | EPICARDIUM Figure 14.3 Layers of the pericardium (the double-layered sac surrounding the heart))

86 14. BODY <€ ~ 13. AORTA OSMOSIS.ORG 1. SUPERIOR/INFERIOR VENA CAVA . RIGHT ATRIUM 3. TRICUSPID VALVE Y. RIGHT VENTRICLE 10. MITRAL/BICUSPID VALVE 11. LEFT VENTRICLE 1. AORTIC VALVE Figure 14.5 Blood flow physiology starting with the superior and inferior vena cavae bringing deoxygenated blood from the body to the right atrium of the heart. VENTRICULAR SYSTOLE VS. DIASTOLE Systole = Ventricular contraction/atrial relaxation = Occurs during S1 sound = Aortic, pulmonic valves open — blood pushed into aorta, pulmonary arteries = Systolic blood pressure o Arterial pressure when ventricles squeeze out blood under high pressure o Peripheral pulse felt Diastole = Ventricular relaxation/atrial contraction = Occurs during S2 sound = Tricuspid, mitral valves open — blood fills ventricles = Diastolic blood pressure = Ventricles fill with more blood (lower pressure) BLOOD DISTRIBUTION = Average adult: 5L/1.32gal total blood volume (not cardiac output) = 10% of total volume (approx. 500ml/0.13gal) in pulmonary arteries, capillaries, pulmonic circulatory veins = 5% of total volume (250ml|/0.07gal) in one of four heart chambers = 15% (750ml/0.29gal) in systemic arteries = 15% to brain = 5% nourishes heart n 25% to kidneys = 25% to Gl organs = 25% to skeletal muscles = 5% to skin = 5% (250mI/0.07gal) in systemic capillaries = 65% (3.25L/0.864gal) in systemic veins = Numbers can change (e.g. exercise) BLOOD FLOW TERMINOLOGY Preload = Amount of blood in left ventricle before contraction = Determined by filling pressure (end diastolic pressure) = “Volume work” of heart Afterload = Resistance (load) left ventricle needs to push against to gject blood during contraction = “Tension work” of heart = Components include = Amount of blood.in systemic circulation

Chapter 14 Cardiovascular Physiology: Cardiovascular Anatomy & Physiology = Degree of arterial vessel wall constriction (for left side of heart, main afterload source is systemic arterial resistance; for right side of heart, main afterload source is pulmonary arterial pressure) Stroke volume (SV) = Blood volume (in liters) pumped by heart per contraction = Determined by amount of blood filling ventricle, compliance of ventricular myocardium Cardiac output (CO) = Blood volume pumped by heart per minute (L/min) = CO =SV * heart rate = Example = SV = 70mL ejected per contraction = HR = 70bpm = CO=70%*70=4900mL/min = 4.9L/min Venous return » Blood-flow from veins back to atria Ejection fraction (EF) = Percentage of blood leaving heart during each contraction = EF = (stroke volumeend diastolic volume) * 100 Frank-Starling Mechanism = Ventricular contraction strength related to amount of ventricular myocardial stretch = Maximum contraction force achieved when myocardial actin, myosin fibers are stretched about 2-2.5 times normal resting length BLOOD VESSEL LAYERS (“TUNICS") Tunica intima (interna) = Innermost layer A. ADULT ~ S LITERS of BLOOD 15% (0.75 L) 10% (0.5 1) ARTERlES PULMONARY CIRCULATION sysTemc | S%(0.as51) \C CIRCULATION | CAPILLARIES 65% (3.25 L) \_/ VEINS 5% (0.35 L) HEART B. SYSTEMIC ARTERIAL BLOOD DISTRIBUTION @ 5% HepeT V\ as% as% @ é) SKELETAL knofie% MUSCLES as% v 1 Gl ORGANS Figure 14.6 A: Total blood volume distribution in an average adult. B: Systemic arterial blood distribution. OSMOSIS.ORG 87

Chapter 14 Cardiovascular Physiology: Cardiovascular Anatomy & Physiology = Fluid moves out of vessel, into interstitial space (space between blood vessels, cells) = Water-soluble substances (ions) cross capillary wall through clefts, between endothelial cells, through large pores in fenestrated capillary walls o Lipid-soluble molecules (oxygen, carbon dioxide) dissolve, diffuse across endothelial cell membranes BULK FLOW = Passive water, nutrient movement across capillary wall down concentration gradient LARGEST ARTERIES L Sy {?’vljyj/ ARTERIOLE CAPILLARY TUNICA INTIMA (SOMETIMES) BASEMENT MEMBRANE METAARTERIOLE VENULE \’?—1 \ Figure 14.8 Key features of different blood vessel types. Key features = Moves large amounts of water, substances in same direction through fenestrated capillaries = Material movement = Faster transport method = Regulates blood, interstitial volume = Filtration, reabsorption = Continuous fluid mixing between plasma, interstitial fluid Types = Filtration: bulk flow when moving from blood to interstitium = Reabsorption: bulk flow when moving from interstitium to blood Other characteristics = Kidney: major site of bulk flow where waste products are filtered out, nutrients reabsorbed = Fluid filters out of capillaries into interstitial space (net filtration) at arteriolar end, reabsorbed (net reabsorption) at venous end = Hydrostatic interstitial fluid pressure draws fluid into capillary = Hydrostatic capillary pressure pushes fluid out of capillary o Colloid interstitial fluid pressure pushes fluid out of capillary = Colloid capillary pressure draws fluid into capillary MICROCIRCULATION = Microcirculation: arterioles + capillaries + venules = Arteriole blood flow through capillary bed, to venule (nutrient, waste, fluid exchange) = Capillary beds composed of vascular shunt (vessel connects arteriole, venule to capillaries), actual capillaries o Terminal arteriole — metarteriole — thoroughfare channel — postcapillary venule o Precapillary sphincter: valve regulates blood flow into capillary = Various chemicals, hormones, vasomotor nerve fibers regulate amount of blood entering capillary bed OSMOSIS.ORG 89

LYMPHATIC ANATOMY & PHYSIOLOGY ~ osms.it/lumphatic-anatomy-physiology =~ LYMPHATIC SYSTEM Function = Fluid balance = Returns leaked interstitial fluid, plasma proteins to blood, heart via lymphatic vessels = Lymph: name of interstitial fluid when in lymph vessels = | ymphedema: lymph dysfunctional/ absent (lymph node removal in cancer) — edema forms = Immunity = Fat absorption Lymphatic capillaries = Collect interstitial fluid leaked by capillaries = Found in all tissues (except bone, teeth, marrow) = Microscopic dead-ended vessels unlike blood capillaries, helps fluid remain inside = Usually found next to blood capillaries = Lymph moves via breathing, muscle contractions, arterial pulsation in tight tissues LYMPHATIC VESSELS INTERSTITIAL x \ CollAGEN FIcLAMENTS - = Carries particles away from inflammation sites/injury towards bloodstream, stopping first through lymph nodes that filter out harmful substances = Overlapping endothelial cells create valves; prevent backflow, infectious spread = | acteals: specialized lymphatic capillaries found in small intestine villi = Carry absorbed fats into blood = Chyle: fat-containing lymph Larger lymphatics = Capillaries — collecting vessels — trunks — ducts — angle of jugular, subclavian veins; right lymphatic duct empties into right angle, thoracic into left = Collecting vessels have more valves, more anastomoses than veins o Superficial collecting vessels follow veins = Deep collecting vessels follow arteries = Lymphatic trunks s Paired: lumbar, bronchomediastinal, subclavian, jugular o Singular: intestinal LYMPHATIC CAPILLARIES MiNIVALVES — One-way 1o Figure 14.9 Lymphatic vessels collect interstitial fluid (which is then called lymph) and return it to the veins. Lymphatic capillaries have minivalves that open when pressure in the interstitial space is higher than in the capillary and shut when pressure in the interstitial space is lower. OSMOSIS.ORG

92 OSMOSIS.ORG LYMPH DRAINS into LYMPH NODES Figure 14.11 In lymph nodes, dendritic cells present pieces of pathogens they come across to B cells. If a dendritic cell presents something foreign to a B cell, the B cell turns into a plasma cell and starts secreting antibodies, which flow into the lymph and exit the lymph node. BeLow DIAPHRAGM | ARovE StoMACH Figure 1412 Spleen location, histology. Lymph nodes = Hundreds scattered throughout body, often grouped along lymphatic vessels o Superficial, deep = Many found in inguinal, axillary, cervical regions = Function = Lymph filtration, immune system activation SpPeenN White Pup Ren Purp = Kidney-shaped formations = Built like tiny spleens, 1-25cm/0.4-9.8in long = Covered by capsule with trabeculae, extend inward; trabeculae divide nodes sectionally = Cortex = Subcapsular sinus, lymphoid follicle, germinal center

Chapter 14 Cardiovascular Physiology: Cardiovascular Anatomy & Physiology = Medulla = Medullary cord, medullary sinus = Lymph flows through afferent lymphatic vessels — enters node through hilum — subcapsular sinus — cortex — medullary sinus — exiting via efferent lymphatic vessels in hilum = Fewer efferent vessels than afferent vessels, slows traffic down — allows node to filter lymphatic fluid = Swollen painful nodes indicate inflammation, painless nodes may indicate cancer Thymus » [ ocated between sternum, aorta in mediastinum = Two lobes, many lobules composed of cortex, medulla o Cortex: T lymphocyte maturation site (immature T lymphocytes move from bone marrow to thymus for maturation) = Medulla: contains some mature T lymphocytes, macrophages, cell-clusters called thymic corpuscles (corpuscles contain special T lymphocytes thought to be involved in preventing autoimmune disease) = Lymphocyte production site in fetal life = Active in neonatal, early life; atrophies with age Bone marrow = B cells: made, mature in bone marrow = T cells: made in bone marrow, mature in thymus Mucosa-associated lymphoid tissue (MALT) = Lymphoid tissue that is associated with mucosal membranes = Tonsils: lymphoid-tissue ring around pharynx o Have crypts (epithelial invaginations) which trap bacteria o Palatine: paired tonsils on each side of pharynx (largest tonsils, most often inflamed) o Lingual: near base of tongue = Pharyngeal: near nasal cavity (called adenoid when inflamed) o Tubal: near Eustachian tube = Peyer’s patches: small bowel MALT Appendix = Worme-like large bowel extension = Contains numerous lymphoid follicles = Fights intestinal infections Figure 1413 Thymus location. TonsiLs Abenoid Paating Figure 1414 Tubal, pharyngeal (adenoid), palatine, and lingual tonsils create a lymphoid-tissue ring around pharynx. OSMOSIS.ORG 93

Chapter 14 Cardiovascular Physiology: Cardiovascular Anatomy & Physiology FIRST HEART SOUND (s1) TRICUSPID VALVE MITRAL VALVE SECOND HEART SOUND (52) AORTIC VALVE PULMONARY VALVE Figure 1415 Valves that close to produce S1 and S2 sounds and optimal auscultation sites. ABNORMAL HEART SOUNDS ~ osms.it/dbnormal-heart-sounds @ ARBNORMAL S1 drift towards each other before onset of systole Loud S1 . . _ = Shorter PR interval — less time to drift = As left ventricle fills, pressure increases closure — wider closure distance — = As left atrium empties, pressure increases louder S1 as it empties against increasingly pressure- loaded ventricle; as atrium approaches empty, pressure begins to decrease ventricular filling pressure — ventricular = Differential diagnosis: short PR interval, pressure crosses critical atrioventricular mild mitral stenosis, hyperdynamic states valve closing threshold while atrial = Short PR interval (< 120ms) pressures are still high — load snap = Normally atrioventricular valve leaflets = Short PR interval — incomplete ventricular emptying — higher OSMOSIS.ORG 95

96 = Mild mitral stenosis o Significant force required to close stenotic mitral valve — large atrioventricular pressure gradient required = Slam shut with increased force, producing loud sound = Hyperdynamic states = Shortened diastole — large amount of ongoing flow across valve during systole — |leaflets wide apart, pressure remains high = Results in forceful atrioventricular valve closure Soft S1 = Differential diagnosis: long PR intervals, severe mitral stenosis, left bundle branch block, chronic obstructive pulmonary disease (COPD), obesity, pericardial effusion = Long PR intervals (> 200ms) = Atrium empties fully — low pressure — low ventricular pressure required to close atrioventricular valves — valves close when ventricle is in early acceleration phase (low pressures) — soft sound » Severe mitral stenosis o eaflets too stiff, fixed to change position Variable S1 = Auscultatory alternans = When observed with severe left ventricular dysfunction, correlate of pulsus alternans = Differential diagnosis: atrioventricular dissociation, atrial fibrillation, large pericardial effusion, severe left ventricular dysfunction Split S1 = S1 usually a single sound o Near-simultaneous mitral, tricuspid valve closures; soft intensity of tricuspid valve closure = Splitting usually from tricuspid valve closure being delayed relative to mitral valve closure = Differential diagnosis: right bundle branch block, left-sided preexcitation, idioventricular rhythm arising from left OSMOSIS.ORG ventricle ABNORMAL Sa. Split S2 = Physiological S2 splitting s Expiration: S1 A2P2 (no split) o Inspiration: S1 A2...P2 (40ms split) = Wide split = Detection: splitting during expiration » Expiration: S1 A2..P2 (slight split) = Inspiration: S1 A2 ...... P2 (wide split) = Differential diagnosis: right bundle branch block, left ventricle preexcitation, pulmonary hypertension, massive pulmonary embolism, severe mitral regurgitation, constrictive pericarditis = Fixed split = Splitting during both expiration, inspiration; does not lengthen during inspiration = Expiration: S1 A2..P2 (slight split) = [nspiration: S1 A2..P2 (slight split) = Differential diagnosis: atrial septal defect, severe right ventricular failure = Reversed split = Split during expiration, but not inspiration s Expiration: S1 P2...A2 (moderate split) = Inspiration: S1 P2A2 = Differential diagnosis: left bundle branch block, right ventricle preexcitation, aortic stenosis/AR Abnormal single S2 variants = Loud P2 o Expiration: S1 A2P2 o Inspiration: S1 A2 .... P2! = Diagnosis: pulmonary hypertension = Left ventricular outflow obstruction = Absent A2 = Expiration: S1 P2 o [nspiration: S1 P2 = Diagnosis: severe aortic valve disease = Fused A2/P2 o Expiration: S1 A2P?2 o Inspiration: S1 A2P2 o Differential diagnosis: ventricular septal defect with Eisenmenger’s syndrome, single ventricle

98 OSMOSIS.ORG Summation gallop = Superimposition of atrial, ventricular gallops during tachycardia = Heart rate 1 — diastole shortens more than systole — S3, S4 brought closer together until they merge HEART MURMURS Key features = Blood flow silent when laminar, uninterrupted = Turbulent flow may generate abnormal sounds (AKA “heart murmurs”) = Murmurs can be auscultated with stethoscope Causes = May be normal in young children, some elderly individuals = | blood viscosity (e.g. anaemia) = | diameter of vessel, valve, orifice (e.g. valvular stenosis, coarctation of aorta, ventricular septal defect) = 1 blood velocity through normal structures (e.g. hyperdynamic states—sepsis, hyperthyroid) = Regurgitation across incompetent valve (e.g. valvular regurgitation) Describing heart murmurs = Specific language used to describe murmurs in diagnostic workup = Timing: refers to timing relative to cardiac cycle o Systolic “flow murmurs”; aortic, pulmonic stenosis; mitral, tricuspid regurgitation; ventricular septal defect; aortic outflow tract obstruction o Diastolic: aortic, pulmonic regurgitation; mitral, tricuspid stenosis = Continuous murmurs are least common, generally seen in children with congenital heart disease (e.g. patent ductus arteriosus, cervical venous hum) = Occasionally may have two related murmurs, one systolic, one diastolic; gives impression of continuous murmur (e.g. concurrent aortic stenosis, aortic regurgitation) = Location = Location on chest wall where murmur is best heard = Radiation = Location where murmur is audible despite not lying directly over heart = Generally radiate in same direction as turbulent blood is flowing = Aortic stenosis: carotid arteries = Tricuspid regurgitation: anterior right thorax = Mitral regurgitation: left axilla = Shape = How sound intensity changes from onset to completion = Shape determined by pattern of pressure gradient driving turbulent flow, loudest segment occurring at time of greatest gradient (moment of highest velocity) = Three basic shapes: crescendo- decrescendo, uniform (holosystolic when occurring during systole), decrescendo = Crescendo-decrescendo, uniform generally systolic; decrescendo murmurs generally diastolic CRESCENDO - DECRESCENDO MURMUR Lt men—] “WHOOSH" DIASTOLE SVSTOLE DIASTOLE S1 62 DECRESCENDO MURMUR Kiasman SYSTOLE DIASTOLE 51 s2 51 UNIFORM MURMUR CLICK S1 s2 Figure 1417 Three basic heart murmur shapes: crescendo-decrescendo, decrescendo, uniform/holosystolic.

Chapter 14 Cardiovascular Physiology: Cardiovascular Anatomy & Physiology = Pitch = High pressure gradients — high pitched murmurs (e.g. mitral regurgitation, ventricular septal defect) o Large volume of blood-flow across low pressure gradients — low pitched murmurs (e.g. mitral stenosis) o [f both high pressure, high flow (severe aortic stenosis), both high, low pitches are produced simultaneously — subjectively unpleasant/“harsh” sounding murmur = Intensity = Murmur loudness graded on scale from I-VI = Dependent on blood velocity generating murmur; acoustic properties of intervening tissue; hearing; examiner experience; stethoscope used, ambient noise presence o |: barely audible o |I: faint, but certainly present o |l easily, immediately heard o |V: associated with thrill (palpable vibration over involved heart valve) o V: heard with only edge of stethoscope touching chest wall = VI: heard without stethoscope (or without it making direct contact with chest wall) = Quality = Subjective, attempt to describe timbre, depends on how many different base frequencies of sound are generated, relative amplitude of various harmonics = Mitral regurgitation: blowing/musical = Mitral stenosis: rumbling = Aortic stenosis: harsh = Aortic regurgitation: blowing o Still’'s murmur (benign childhood): musical o Patent ductus arteriosus: machine-like Diagnostic maneuvers (dynamic auscultation) = Some maneuvers may elicit characteristic intensity/timing changes (changes in hemodynamics during maneuvers) = Dynamic auscultation: listening for subtle changes during physical maneuvers = [nspiration = | intrathoracic pressure — 1 pulmonary venous return to right heart — 1 right heart stroke volume — right sided murmurs — 1 intensity = Dilation of pulmonary vascular system — | pulmonary venous return to left side of heart — | left heart stroke volume — left side murmurs — | intensity = Expiration = 1 intrathoracic pressure — | venous return to right heart — | right ventricle stroke volume — | intensity of right sided murmurs = 1 pulmonary venous return to left side — 1 left ventricle stroke volume — left sided murmur — 71 intensity = Valsalva maneuver = Forceful exhalation against closed glottis = | venous return to heart — | left ventricular volume — | cardiac output = Murmurs of hypertrophic obstructive cardiomyopathy, occasionally mitral valve prolapse — 1 intensity = All other systolic murmurs — | intensity = [sometric handgrip = Squeeze two objects (such as rolled towels) with both hands = Do not simultaneously Valsalva o [f unconscious, simulate by transient arterial occlusion (BP cuffs applied to both upper arms, inflated to 20- 40mmHg above systolic blood pressure for 20 seconds) = 1 venous return, 1 sympathetic tone — 1 heart rate, systemic venous return — 1 cardiac output — murmurs from mitral regurgitation, aortic regurgitation, ventricular septal defect — 1 intensity = Murmur from hypertrophic obstructive cardiomyopathy — | intensity = Murmur from aortic stenosis — most commonly unchanged = | eg elevation o Lying supine, both legs raised 45° = 1 venous return — 1 left ventricular volume = Murmur from hypertrophic obstructive cardiomyopathy — | intensity = Murmurs from aortic stenosis, mitral regurgitation may — 1 intensity OSMOSIS.ORG 99

Chapter 14 Cardiovascular Physiology: Cardiovascular Anatomy & Physiology change throughout murmur o Referred to as “flat” murmur because intensity does not change = Radiates to axilla due to direction of regurgitant jet = Auscultatory summary: S1. Flat murmur. S2 = Tricuspid regurgitation = Tricuspid valve auscultation site: 4/5th intercostal, left sternal margin = Holo-/pansystolic murmur = Normal S1 occurs due to tricuspid valve closure — pulmonic valve closed, pressure rises in right ventricle o [n tricuspid regurgitation, valve cannot completely close — pressure builds in right ventricle — blood forced back out through partially closed tricuspid valve — murmur is continuous as long as pressures remain high enough = Pulmonic valve opens to redirect blood —s left ventricle maintains contraction (thus raises pressure) — blood continues flowing through partially closed tricuspid valve (through whole systole) = Arium becomes more compliant as it fills — atrium pressure does not significantly increase = Right ventricle pressure notably higher than that of right atrium — murmur sound does not change throughout murmur = Referred to as “flat” murmur (intensity does not change) = Auscultatory summary: S1. flat murmur. S2 = Mitral valve prolapse = Mitral valve auscultation site: 5% intercostal space, midclavicular line/apex = Mitral valve billows into left atrium — clicking sound (unlike aortic stenosis, not associated with ejection of blood, non-ejection click, mid-late systolic) = Ventricle contracts — mitral valve closure — S1 — pressure rises — mitral valve accelerates into left atrium — stops abruptly (chordae tendineae restraint) — rapid tensing — click = Often associated with mitral regurgitation — after click murmur of mitral regurgitation may follow = Auscultatory summary: S1. Mid systolic click with late systolic murmur. S2 Diastolic murmurs = Aortic regurgitation o Aortic regurgitation auscultation site: left parasternal border o Blood flows back through incompletely closed aortic valve o Occurs between S2, S1 = S2, aortic valve closure — mitral valve opens, heart in diastole — blood enters left ventricle through regurgitant valve, through normal filling via mitral valve o [nitially, low pressure in ventricle (compared to systemic blood pressure forcing blood through regurgitant valve) — ventricle fills — as pressure mounts, less flow through regurgitant valve — decrescendo murmur o Early diastolic decrescendo murmur o Auscultatory summary: S1. S2. Early diastolic decrescendo murmur. S1 = Pulmonic regurgitation = Pulmonic regurgitation auscultation site: upper left parasternal border o Blood flows back through incompletely closed pulmonic valve o Occurs between S2, S1 = S2 aortic valve closure — tricuspid valve opens, heart in diastole — incomplete pulmonic valve closure — right ventricle fills via incompletely closed pulmonic valve as well as tricuspid valve = [nitially — low ventricle pressure allows for high flow through regurgitant valve — pressure rises, | flow through regurgitant valve — decrescendo murmur = Early diastolic decrescendo murmur o Auscultatory summary: S1. S2. Early diastolic decrescendo murmur. S1 = Mitral stenosis = Mitral valve auscultation site: 5% intercostal space, midclavicular line/apex = Mitral valve can't open efficiently o S2 — agortic valve closure — milliseconds later, mitral valve should open (fill ventricle during diastole), only small opening occurs OSMOSIS.ORG 101

102 OSMOSIS.ORG SystoLIC MURMURS ”LUB“ QDUB“ — - 1I WHOOSH DIASTOLE I SVSTOLE DIASTOLE S1 S2 STENOSIS AORTIC VALVE STENOSIS LAORTIC or PULHONIC VALVE REGURGITATION LMITRAL or TRICUSPID VALVE TRICUSPID VALVE REGURGITATION MITRAL VALVE REGURGITATION MITRAL VALVE PROLAPSE VENTRAL SEPTAL DEefFecT ~ t§ SEVERE ENOUGH — * HOLOSYSTOLIC MURMUR MITRAL REGURGITATION j:/\m‘?zlun VENTRICLE - = r Figure 14148 Causes of systolic murmurs.