The Cardiovascular SystemThe Cardiovascular System

Organs of the Cardiovascular Organs of the Cardiovascular System System

HeartHeartBlood vesselsBlood vessels– ArteriesArteries

ArteriolesArteriolesCapillariesCapillaries

– VeinsVeinsVenulesVenules

The Heart The Heart Muscular organ the size of a Muscular organ the size of a fistfistFour chambers – L/R Four chambers – L/R Ventricles L/R AtriaVentricles L/R AtriaEndocardium- lines the Endocardium- lines the heart chambersheart chambersMyocardium- muscle layerMyocardium- muscle layerPericardium- membranous Pericardium- membranous outer coveringouter covering

AtriaAtria

Right Atrium (RA)- Right Atrium (RA)- right upper chamber- right upper chamber- receives blood from receives blood from body- deoxygenated body- deoxygenated bloodbloodLeft atrium (LA)- left Left atrium (LA)- left upper heart.- receives upper heart.- receives oxygenated blood oxygenated blood from lungs and sends from lungs and sends it to the left ventricleit to the left ventricle

VentriclesVentricles

Right ventricle- (RV)- Right ventricle- (RV)- right lower chamber- right lower chamber- receives blood from right receives blood from right atrium and sends it to the atrium and sends it to the lungs through pulmonary lungs through pulmonary arteryartery

Left Ventricle (LV)- lower Left Ventricle (LV)- lower left chamber- receives left chamber- receives blood from left atrium and blood from left atrium and sends it through the aorta sends it through the aorta to the body.to the body.

AortaAorta: The main : The main trunk of the systemic trunk of the systemic arteries, carrying arteries, carrying blood from the left blood from the left side of the heart to side of the heart to the arteries of all the arteries of all limbs and organs. limbs and organs. Pulmonary Artery Pulmonary Artery carries blood to carries blood to lungslungs

Right Atrium

Right Ventricle

Left Atrium

Left Ventricle

Aorta

pulmonary artery

Tricuspid valveTricuspid valve controls blood controls blood flow between the flow between the right atrium and right atrium and ventricleventricleMitral valveMitral valve controls blood controls blood movement movement between the left between the left atrium and atrium and ventricleventricle

Right Atrium

Right Ventricle

Left Atrium

Left Ventricle

Tricuspid Valve

Mitral Valve

Pulmonary valvePulmonary valve controls blood controls blood movement from movement from right ventricle into right ventricle into pulmonary artery pulmonary artery The The aortic valveaortic valve controls blood flow controls blood flow from the left from the left ventricle to the ventricle to the aortaaorta

Right Atrium

Right Ventricle

Left Atrium

Left Ventricle

Tricuspid Valve

Pulmonary valve

Mitral Valve

Aortic valve

ArteriesArteries• Tubes that carry Tubes that carry

blood away from the blood away from the heart. heart.

• Muscular elastic Muscular elastic wallswalls

• Form arterioles Form arterioles which form which form capillariescapillaries

• Carry blood and Carry blood and oxygen to the body oxygen to the body cellscells

Veins• Tubes that carry blood toward the heart•Thinner muscular walls•Carry blood back to heart•Cuplike valves to help move blood

Coronary ArteriesCoronary ArteriesSupply blood to the Supply blood to the heart muscle.heart muscle.The heart needs a The heart needs a large amount of large amount of blood and 5-7% of blood and 5-7% of blood flows blood flows through the through the coronary arteries.coronary arteries.

CapillariesCapillariesCapillaries- tubes that Capillaries- tubes that connect arteries and connect arteries and veinsveinsWalls only one cell Walls only one cell thickthickSite for exchange of Site for exchange of nutrients and oxygen nutrients and oxygen from blood cells and from blood cells and carbon dioxide and carbon dioxide and wastes to the bloodwastes to the blood

BloodBlood

The body contains 4 to The body contains 4 to 6 quarts6 quartsContains Plasma: Contains Plasma: antibodies, nutrients, antibodies, nutrients, gases, waste productsgases, waste productsProduced in bone Produced in bone marrowmarrowWhite and red blood White and red blood cells cells

Chapter 18, Cardiovascular System Chapter 18, Cardiovascular System 1515

Heart Physiology: Sequence of ExcitationHeart Physiology: Sequence of Excitation

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Cardiac CycleCardiac CycleCardiac cycle refers to all events Cardiac cycle refers to all events associated with blood flow through associated with blood flow through the heartthe heart– SystoleSystole – contraction of heart muscle – contraction of heart muscle– DiastoleDiastole – relaxation of heart muscle – relaxation of heart muscle

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Phases of the Cardiac CyclePhases of the Cardiac Cycle

Ventricular fillingVentricular filling – mid-to-late – mid-to-late diastolediastoleVentricular systole (contraction)Ventricular systole (contraction)– Atria relax Atria relax – Rising ventricular pressure results in Rising ventricular pressure results in

closing of AV valvesclosing of AV valves

Phases of the Cardiac CyclePhases of the Cardiac CycleIsovolumetric relaxationIsovolumetric relaxation – early – early diastolediastole– Ventricles relaxVentricles relax– Backflow of blood in Backflow of blood in aorta and pulmonary aorta and pulmonary

trunktrunk closes semilunar valves closes semilunar valvesDicrotic notchDicrotic notch – brief rise in aortic – brief rise in aortic pressure caused by backflow of blood pressure caused by backflow of blood rebounding off semilunar valvesrebounding off semilunar valves

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Heart SoundsHeart SoundsHeart sounds (lub-dup) are Heart sounds (lub-dup) are associated with closing of heart associated with closing of heart valvesvalves– First soundFirst sound occurs as occurs as AV valves closeAV valves close

and signifies and signifies beginning of systole beginning of systole (contraction)(contraction)

– Second soundSecond sound occurs when occurs when SL valves SL valves closeclose at the at the beginning of ventricular beginning of ventricular diastole (relaxation)diastole (relaxation)

Cardiac Output: ExampleCardiac Output: Example

CO (ml/min) = HR (75 beats/min) x SV CO (ml/min) = HR (75 beats/min) x SV (70 ml/beat)(70 ml/beat)CO = 5250 ml/min (5.25 L/min)CO = 5250 ml/min (5.25 L/min)

Measuring Cardiac FunctionMeasuring Cardiac FunctionBlood PressureBlood Pressure

ElectrocardiogramElectrocardiogram

Stress TestStress Test

AngiographyAngiography

Blood PressureBlood PressureMeasure of fluid pressure within systemMeasure of fluid pressure within systemSystolic Pressure: Pressure generated by Systolic Pressure: Pressure generated by contractioncontractionDiastolic Pressure: Pressure achieved Diastolic Pressure: Pressure achieved between contractions. between contractions.

ElectrocardiographyElectrocardiographyElectrical activity is recorded by Electrical activity is recorded by electrocardiogram (ECG)electrocardiogram (ECG)P wave corresponds to depolarization of P wave corresponds to depolarization of SA nodeSA nodeQRS complex corresponds to ventricular QRS complex corresponds to ventricular depolarizationdepolarizationT wave corresponds to ventricular T wave corresponds to ventricular repolarizationrepolarizationAtrial repolarization record is masked by Atrial repolarization record is masked by the larger QRS complexthe larger QRS complex

ElectrocardiogramElectrocardiogramMeasure of the Measure of the electrical activity of electrical activity of the heartthe heart

Stress TestStress TestECG during ECG during exerciseexercise

AngiographyAngiographyCardiac catheterizationCardiac catheterizationInject dye into heartInject dye into heartX-ray to examine blockagesX-ray to examine blockages

Disorders Related to CVSDisorders Related to CVSAtrial Septal DefectAtrial Septal DefectVentricular Septal DefectVentricular Septal DefectMitral valve prolapseMitral valve prolapse

Congestive heart failure (CHF) is Congestive heart failure (CHF) is caused by:caused by:– Coronary atherosclerosisCoronary atherosclerosis– Persistent high blood pressurePersistent high blood pressure– Multiple myocardial infarctsMultiple myocardial infarcts– Dilated cardiomyopathy (DCM) – main Dilated cardiomyopathy (DCM) – main

pumping chambers of the heart are pumping chambers of the heart are dilated and contract poorly dilated and contract poorly

Clinical ProblemsClinical ProblemsMI = myocardial infarctionMI = myocardial infarction– death of area of heart muscle from lack of Odeath of area of heart muscle from lack of O22

– replaced with scar tissuereplaced with scar tissue– results depend on size & location of damageresults depend on size & location of damageBlood clotBlood clot– use clot dissolving drugs streptokinase or t-PA use clot dissolving drugs streptokinase or t-PA

& heparin& heparin– balloon angioplastyballoon angioplastyAngina pectorisAngina pectoris– heart pain from ischemia heart pain from ischemia ((lack of blood flow lack of blood flow

and oxygen ) of cardiac muscleand oxygen ) of cardiac muscle