THE HEARTTHE HEARTPresented by: Presented by:

Fe M. Compas, RN, MANFe M. Compas, RN, MAN

HEARTHEART

A 4 chambered, A 4 chambered, hollow, muscular hollow, muscular organorgan

Lies between the Lies between the lungs and within lungs and within the middle the middle mediastinummediastinum

About the size of About the size of the fistthe fist

HEARTHEART Shaped like an inverted Shaped like an inverted

conecone- base - base - upward, backward - upward, backward and to the right and to the right

- apex- apex- downward, forward - downward, forward and to the left and to the left- pulsation felt 2-3 - pulsation felt 2-3 fingerbreadths below fingerbreadths below the nipplethe nipple

COVERING OF THE HEARTCOVERING OF THE HEARTPERICARDIUMPERICARDIUM

fibro-serous coveringfibro-serous covering

Parietal PericardiumParietal Pericardium

Visceral PericardiumVisceral Pericardium- EPICARDIUM- EPICARDIUM- outermost wall of the heart- outermost wall of the heart

COVERING OF THE HEARTCOVERING OF THE HEART

WALLS OF THE HEARTWALLS OF THE HEART EPICARDIUM or VISCERAL PERICARDIUMEPICARDIUM or VISCERAL PERICARDIUM

- outermost layer- outermost layer

MYOCARDIUMMYOCARDIUM- middle muscular layer- middle muscular layer- contracts rhythmically and spontaneously - contracts rhythmically and spontaneously through the conduction system of the heartthrough the conduction system of the heart

ENDOCARDIUMENDOCARDIUM- innermost layer- innermost layer

MAJOR BLOOD VESSELS ATTACHED TO MAJOR BLOOD VESSELS ATTACHED TO THE HEARTTHE HEART

SUPERIOR VENA CAVASUPERIOR VENA CAVA- drains blood from the upper part of the body to the - drains blood from the upper part of the body to the right side of the heartright side of the heart

INFERIOR VENA CAVAINFERIOR VENA CAVA- drains blood from the lower part of the body to the - drains blood from the lower part of the body to the right side of the heartright side of the heart

PULMONARY TRUNKPULMONARY TRUNK- brings unoxygenated blood from the right side of - brings unoxygenated blood from the right side of the heart to the lungs for oxygenationthe heart to the lungs for oxygenation

PULMONARY VEINSPULMONARY VEINS- brings oxygenated blood from the lungs to the left - brings oxygenated blood from the lungs to the left side of the heartside of the heart

AORTAAORTA- brings oxygenated blood from the left side of the - brings oxygenated blood from the left side of the heart to the whole bodyheart to the whole body

CHAMBERS OF THE HEART :CHAMBERS OF THE HEART :ATRIAATRIA

RIGHT ATRIUM (RA)RIGHT ATRIUM (RA)- larger that the left- larger that the left- thinner wall- thinner wall- portal of entry to 3 veins- portal of entry to 3 veins- superior vena cava- superior vena cava- inferior vena cava- inferior vena cava- coronary sinus- coronary sinus

LEFT ATRIUM (LA)LEFT ATRIUM (LA)- thicker wall- thicker wall- portal of entry to 4 - portal of entry to 4 pulmonary veinspulmonary veins

INTERATRIAL SEPTUMINTERATRIAL SEPTUM- septum (wall) that - septum (wall) that separates the right and separates the right and left atriumleft atrium

FOSSA OVALISFOSSA OVALIS- located in the septum- located in the septum- represents the - represents the foramen ovale foramen ovale

- opening between - opening between the the 2 atria during 2 atria during fetal fetal life life

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CHAMBERS OF THE HEART :CHAMBERS OF THE HEART :VENTRICLESVENTRICLES

RIGHT VENTRICLE (RV)RIGHT VENTRICLE (RV) - wall thinner than left ventricle- wall thinner than left ventricle - receives blood from the right atrium- receives blood from the right atrium- pumps blood to the lungs through the pulmonary - pumps blood to the lungs through the pulmonary trunktrunk

LEFT VENTRICLE (LV)LEFT VENTRICLE (LV)- very thick walled- very thick walled- receives blood from the left atrium- receives blood from the left atrium- pumps blood to the whole body through the aorta- pumps blood to the whole body through the aorta

INTERVENTRICULAR SEPTUMINTERVENTRICULAR SEPTUM

VALVES OF THE HEARTVALVES OF THE HEART PURPOSE :PURPOSE :

- prevent backflow or reflux of blood between - prevent backflow or reflux of blood between chamberschambers

ATRIOVENTRICULAR (AV) VALVESATRIOVENTRICULAR (AV) VALVES SEMILUNAR VALVES (SL) VALVESSEMILUNAR VALVES (SL) VALVES

VALVES OF THE HEARTVALVES OF THE HEARTAtrioventricular (AV) Atrioventricular (AV)

ValvesValves TRICUSPID VALVETRICUSPID VALVE

- guards opening or - guards opening or orifice between RV and orifice between RV and RARA

BICUSPID or MITRAL BICUSPID or MITRAL VALVEVALVE- guards orifice between - guards orifice between LV and LALV and LA

Semilunar (SL) ValvesSemilunar (SL) Valves PULMONARY or PULMONARY or

PULMONIC VALVEPULMONIC VALVE- guards opening - guards opening between RV and between RV and Pulmonary TrunkPulmonary Trunk

AORTIC VALVEAORTIC VALVE- guards opening - guards opening between LV and Aortabetween LV and Aorta

FUNCTION OF THE HEARTFUNCTION OF THE HEART Pump bloodPump blood

Right ventricleRight ventricle- pumps blood to the pulmonary circulatory - pumps blood to the pulmonary circulatory systemsystem

Left ventricleLeft ventricle- pumps blood to the whole body- pumps blood to the whole body

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CONDUCTION SYSTEM OF THE HEARTCONDUCTION SYSTEM OF THE HEART SINO-ATRIAL (SA) NODESINO-ATRIAL (SA) NODE ATRIO-VENTRICULAR (AV) NODEATRIO-VENTRICULAR (AV) NODE BUNDLE OF HIS or AV BUNDLEBUNDLE OF HIS or AV BUNDLE PURKINJE FIBERSPURKINJE FIBERS

CONDUCTION SYSTEM OF THE HEARTCONDUCTION SYSTEM OF THE HEARTSINO-ATRIAL (SA) NODESINO-ATRIAL (SA) NODE Posterior wall of the RA Posterior wall of the RA

at the junction of the at the junction of the SVC and the RASVC and the RA

Cardiac PACEMAKERCardiac PACEMAKER- initiates the heartbeat- initiates the heartbeat

ATRIO-VENTRICULAR (AV) ATRIO-VENTRICULAR (AV) NODENODE

Right side of the inter-Right side of the inter-atrial septum atrial septum

BUNDLE OF HIS or AV BUNDLE OF HIS or AV BUNDLEBUNDLE

Goes down the right Goes down the right side of the side of the interventricular septuminterventricular septum

Divides into right and Divides into right and left branchesleft branches

PURKINJE FIBERSPURKINJE FIBERS Conducting fibers of the Conducting fibers of the

right and left Bundle right and left Bundle branchesbranches

Extend over the Extend over the undersurface of the undersurface of the endocardiumendocardium

CONDUCTION SYSTEM OF THE HEARTCONDUCTION SYSTEM OF THE HEART Electrical activity accompanies the spread of Electrical activity accompanies the spread of

excitation over the heartexcitation over the heart

ELECTROCARDIOGRAM (ECG or EKG)ELECTROCARDIOGRAM (ECG or EKG)- instrument used to record the electrical - instrument used to record the electrical activity of the heart using electrodes placed activity of the heart using electrodes placed on the anterior chest wallon the anterior chest wall

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ECGECG P waveP wave

- atrial depolarization- atrial depolarization

QRS complexQRS complex- ventricular depolarization- ventricular depolarization

P-R intervalP-R interval- atrioventricular interval- atrioventricular interval

T waveT wave- ventricular repolarization- ventricular repolarization

CARDIAC CYCLECARDIAC CYCLE Atrial depolarization Atrial depolarization

- initiates atrial - initiates atrial contraction which forces contraction which forces blood into the ventriclesblood into the ventricles

Atrial relaxationAtrial relaxation- AV valves begin to close- AV valves begin to close

Ventricular depolarizationVentricular depolarization- initiates ventricular - initiates ventricular contractioncontraction- closure of the AV valves - closure of the AV valves - first heart sound - first heart sound (S1 or lubb) (S1 or lubb)

Increase in ventricular Increase in ventricular pressurepressure

SL valves opensSL valves opens Ejection periodEjection period Ventricular relaxationVentricular relaxation

- pressure within ventricle - pressure within ventricle fallsfalls- closure of the SL valves- closure of the SL valves- second heart sound - second heart sound (S2 or (S2 or dubb)dubb)

Atrial depolarizationAtrial depolarization

HEART RATEHEART RATE Obtained by placing the stethoscope between Obtained by placing the stethoscope between

the 5the 5thth and 6 and 6thth ICS MCL ICS MCL- area just below the left nipple- area just below the left nipple

1 heart beat1 heart beat == lubb and dubblubb and dubb

60 – 100 bpm60 – 100 bpm

Factors Affecting Heart RateFactors Affecting Heart Rate Size of the bodySize of the body

- the smaller the body, the higher the rate- the smaller the body, the higher the rate- mouse- mouse == 1,000/min1,000/min- elephant - elephant == 30/min30/min- man- man == 60 – 80/min60 – 80/min

AgeAge- fetal life- fetal life == 120 – 160120 – 160- newborn- newborn == 120 – 140120 – 140- young children - young children == 100 – 120100 – 120- adults- adults == 60 - 8060 - 80

Body positionBody position- 5 – 10 beats/min more when standing erect- 5 – 10 beats/min more when standing erect

Factors Affecting Heart RateFactors Affecting Heart Rate Increased heart rate withIncreased heart rate with

- acute bleeding- acute bleeding- muscular activity- muscular activity- emotional excitement- emotional excitement- eating and right after a meal- eating and right after a meal- warm baths or hot drinks- warm baths or hot drinks- during ovulation- during ovulation

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REGULATION OF HEART RATEREGULATION OF HEART RATE Nervous regulationNervous regulation

- parasympathetic vs sympathetic stimulation- parasympathetic vs sympathetic stimulation- aortic reflex - aortic reflex

- stimulated when BP is high- stimulated when BP is high- carotid sinus reflex- carotid sinus reflex

- stimulated when BP is high- stimulated when BP is high Chemical regulationChemical regulation

- aortic and carotid sinus reflex- aortic and carotid sinus reflex- - O2 or O2 or CO2 increases heart rate, vis-a-vis CO2 increases heart rate, vis-a-vis

Mechanical regulationMechanical regulation- Starling’s Law of the Heart- Starling’s Law of the Heart- - flow of blood into heart distends myocardium flow of blood into heart distends myocardium HRHR

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BLOOD PRESSUREBLOOD PRESSURE SYSTOLIC PRESSURESYSTOLIC PRESSURE

- the pressure that develops in the large - the pressure that develops in the large arteries during each left ventricular arteries during each left ventricular contractionscontractions- 120 mmHg- 120 mmHg

DIASTOLIC PRESSUREDIASTOLIC PRESSURE- the pressure in the arterial system between - the pressure in the arterial system between heart beatsheart beats- 80 mmHg- 80 mmHg

Normal Blood Pressure = 120/80 mmHgNormal Blood Pressure = 120/80 mmHg

BLOOD PRESSUREBLOOD PRESSUREBLOOD PRESSURE BLOOD PRESSURE Equivalent to cardiac output and total Equivalent to cardiac output and total

peripheral resistanceperipheral resistance

CARDIAC OUTPUTCARDIAC OUTPUT Volume of blood pumped out of the ventricles Volume of blood pumped out of the ventricles

in 1 minutein 1 minute

Stroke Volume Stroke Volume XX Heart RateHeart Rate 60 – 70 ml60 – 70 ml XX 60 – 80 60 – 80

BLOOD PRESSUREBLOOD PRESSUREFactors contributing to Cardiac Output Factors contributing to Cardiac Output

Venous returnVenous return Force of cardiac contractionForce of cardiac contraction Heart rateHeart rate

BLOOD SUPPLY OF THE HEARTBLOOD SUPPLY OF THE HEART The heart also needs blood supply for its nourishmentThe heart also needs blood supply for its nourishment

RIGHT CORONARY ARTERYRIGHT CORONARY ARTERY- RA (SA node)- RA (SA node)- RV- RV- inferior surface of the interventricular septum- inferior surface of the interventricular septum- inferior surfaces of the LV- inferior surfaces of the LV

LEFT CORONARY ARTERYLEFT CORONARY ARTERY- Left anterior descending artery & Left circumflex - Left anterior descending artery & Left circumflex artery artery - superior 2/3 of the interventricular septum- superior 2/3 of the interventricular septum- superior and lateral surfaces of the LV- superior and lateral surfaces of the LV