Chapter 11Chapter 11CARDIOVASCULAR SYSTEMCARDIOVASCULAR SYSTEM

The heart is a muscle that pumps The heart is a muscle that pumps blood. blood.

Blood vessels carry the blood.Blood vessels carry the blood.

PRACTITIONERSPRACTITIONERS

Cardiology (cardi/o = heart)Cardiology (cardi/o = heart)

Cardiologist Cardiologist Interventional cardiologistInterventional cardiologist

Performs procedures and inserts devices Performs procedures and inserts devices

Cardiac surgeonCardiac surgeon

Cardiovascular surgeon (vascul/o = Cardiovascular surgeon (vascul/o = vessel)vessel)

Treats vesselsTreats vessels

HEART FACTSHEART FACTS Located in center of thoracic cavityLocated in center of thoracic cavity

Between the lungs & behind the sternumBetween the lungs & behind the sternum Size of your fistSize of your fist

Points (bottom, apex) left Points (bottom, apex) left

Three-layered wallThree-layered wall Pericardium – outer layer of fibrous tissuePericardium – outer layer of fibrous tissue Myocardium – middle layer of thick Myocardium – middle layer of thick

muscle (my/o)muscle (my/o) Endocardium – inner layer of epithelial Endocardium – inner layer of epithelial

cells cells

Anatomy & Physiology of Anatomy & Physiology of Heart and Surrounding Heart and Surrounding

Structures Structures

HEART ANATOMYHEART ANATOMY Septum (sept/o = partition)Septum (sept/o = partition)

Separates the two sides of the heart (L & R)Separates the two sides of the heart (L & R) 4 chambers4 chambers

Atria (atrium) – 2 upper chambers (atri/o)Atria (atrium) – 2 upper chambers (atri/o) Ventricles – 2 lower chambers (ventricul/o)Ventricles – 2 lower chambers (ventricul/o)

Valves connect upper and lower chambersValves connect upper and lower chambers Bicuspid valve – left side (bi = two) Bicuspid valve – left side (bi = two)

Also called mitral valveAlso called mitral valve Tricuspid valve – right sideTricuspid valve – right side Open and close togetherOpen and close together Prevent blood from flowing back into the atriaPrevent blood from flowing back into the atria

HEART ANATOMY (con’t)HEART ANATOMY (con’t) 2 additional valves in ventricles2 additional valves in ventricles

Pulmonary valve –opening of pulmonary Pulmonary valve –opening of pulmonary arteryartery

Aortic valve –opening of the aortaAortic valve –opening of the aorta Work at the same time Work at the same time

Name the valves

(#5 is not a valve)

1. Pulmonary Valve2. Tricuspid Valve3. Mitral (Bicuspid) Valve4. Aortic Valve5. Heart Apex

Check your labels!

INTERNAL VIEW OF HEARTINTERNAL VIEW OF HEART

HEART ACTIONHEART ACTION Heart contracts to pump bloodHeart contracts to pump blood

Systole – contraction phase Systole – contraction phase Diastole – relaxation phase Diastole – relaxation phase

Heartbeat consists of:Heartbeat consists of: Contraction by atria, then ventriclesContraction by atria, then ventricles Together = cardiac cycleTogether = cardiac cycle

Average heart beat is 72/minAverage heart beat is 72/min Cardiac output = volume of blood Cardiac output = volume of blood

pumped in 1 min. pumped in 1 min.

Regulation of Cardiac Cycle- controlled by the cardiac center within the medulla oblongata. The cardiac center signals heart to increase or decrease its rate according to many factors that the brain constantly monitors.

•Muscle Activity

•Body Temperature

•Blood ion levels (potassium & calcium)

BLOOD FLOW THROUGH THE BLOOD FLOW THROUGH THE HEARTHEART

Pulmonary circulationPulmonary circulation Right side of heart carries blood to lungsRight side of heart carries blood to lungs Return of de-oxygenated blood from the Return of de-oxygenated blood from the

bodybody Blood flow to pick up oxygenated blood in Blood flow to pick up oxygenated blood in

lungslungs

Systemic circulationSystemic circulation Left side of heart carries blood to body Left side of heart carries blood to body Oxygenated blood returns from lungsOxygenated blood returns from lungs Oxygenated blood sent out to body cells Oxygenated blood sent out to body cells

via aorta via aorta

CONDUCTION SYSTEMCONDUCTION SYSTEM Works like an electrical circuitWorks like an electrical circuit

Signal flows fromSignal flows from SA node –begins process SA node –begins process

Pacemaker of heartPacemaker of heart Determines rhythm Determines rhythm

AV nodeAV node Right and left bundle branches (Bundle of Right and left bundle branches (Bundle of

His)His) Purkinje fibersPurkinje fibers

CONDUCTION SYSTEM CONDUCTION SYSTEM

Plasma (55% of the blood)Plasma (55% of the blood) A straw-colored fluid which is about 90% water and 10% A straw-colored fluid which is about 90% water and 10%

dissolved gases, salts, nutrients, enzymes, hormones, dissolved gases, salts, nutrients, enzymes, hormones, waste products and plasma proteinswaste products and plasma proteins

Cells (45% of the blood)Cells (45% of the blood) RBC’s RBC’s

Most numerous (5-6 million)Most numerous (5-6 million) Contain hemoglobin, which is the iron-containing protein that Contain hemoglobin, which is the iron-containing protein that

binds oxygenbinds oxygen WBC’s (leukocytes) (4,000-10,000)WBC’s (leukocytes) (4,000-10,000)

They are the army of the circulatory systemThey are the army of the circulatory system May increase dramatically when the body is fighting an May increase dramatically when the body is fighting an

infectioninfection Platelets (250,000 – 400,000)Platelets (250,000 – 400,000)

Help in blood clotting by clumping together at the injury to Help in blood clotting by clumping together at the injury to prevent blood from flowing out of the cutprevent blood from flowing out of the cut

Parts of the Blood

BLOOD VESSELSBLOOD VESSELS VesselVessel

Vas/oVas/o Angi/oAngi/o

Arteries (arteri/o)Arteries (arteri/o) Carries blood away from the heartCarries blood away from the heart Largest artery is the aortaLargest artery is the aorta

Get smaller – form arterioles (arteriol/o)Get smaller – form arterioles (arteriol/o)

Arterioles change into capillaries Arterioles change into capillaries Nutrients and gases are exchangedNutrients and gases are exchanged

VESSELS (con ‘t) VESSELS (con ‘t) Venous systemVenous system

Carries blood back to heartCarries blood back to heart Capillaries form into tiny venules Capillaries form into tiny venules Veins (ven/o , phleb/o)Veins (ven/o , phleb/o) Largest = superior and inferior venae cavaeLargest = superior and inferior venae cavae

Veins have one-way valves to prevent back flow of Veins have one-way valves to prevent back flow of bloodblood

Lumen: central opening of vesselLumen: central opening of vessel

Pulse: artery expanding and contractingPulse: artery expanding and contracting

Arterial system helps maintain body’s blood Arterial system helps maintain body’s blood pressure: constrict and dilate to keep an even pressure: constrict and dilate to keep an even pressure gradientpressure gradient

PULSE POINTS (palpable PULSE POINTS (palpable pulses)pulses)

HEART FACTSHEART FACTS Heart has a circulatory system to nourish the Heart has a circulatory system to nourish the

heart muscle heart muscle Called coronary circulation (coron/o = circle or Called coronary circulation (coron/o = circle or

crown)crown) Right and left coronary arteriesRight and left coronary arteries

Decreased blood flow leads to heart tissue death Decreased blood flow leads to heart tissue death Myocardial infarction (heart attack) Myocardial infarction (heart attack)

Blood pressure (BP) Blood pressure (BP) Hypertension = Elevated BPHypertension = Elevated BP

Increased resistance in vessels – Poor blood flowIncreased resistance in vessels – Poor blood flow HypotensionHypotension

Too little blood flowing to organs Too little blood flowing to organs Read: systolic pressure (#) /diastolic pressure (#) Read: systolic pressure (#) /diastolic pressure (#)

Goal is ~ 120/80 Goal is ~ 120/80

WELLNESS & ILLNESSWELLNESS & ILLNESS Listen to the heart with a stethoscopeListen to the heart with a stethoscope

Lub - dub = S1, S2 Lub - dub = S1, S2 S1 – closing of AV valves as ventricles contract S1 – closing of AV valves as ventricles contract

(systole)(systole) S2 – closing of semilunar valves closing in S2 – closing of semilunar valves closing in

relaxation diastole relaxation diastole

Listen to specific areas of heart for:Listen to specific areas of heart for: Abnormal heart soundsAbnormal heart sounds Valve defects Valve defects

Heart Sounds - Opening and Closing of Valves, "Lub Dub"

Stethoscope - instrument to listen and measure heart sounds

FETUSES & NEWBORNSFETUSES & NEWBORNS At birth, lungs inflate and aeration At birth, lungs inflate and aeration

beginsbegins Congenital heart defectsCongenital heart defects

Impaired cardiac functionImpaired cardiac function ASD: opening between atriumASD: opening between atrium VSD: opening between ventriclesVSD: opening between ventricles PDA: persistent fetal circulationPDA: persistent fetal circulation Coarctation of aorta: narrowing of Coarctation of aorta: narrowing of

descending portion of aortadescending portion of aorta

CHILDRENCHILDREN

MurmursMurmurs Innocent murmursInnocent murmurs Functional murmurs Functional murmurs

ADULTS –Risk FactorsADULTS –Risk Factors Risk factors for heart diseaseRisk factors for heart disease

Cannot be controlled:Cannot be controlled: Age, family history, genderAge, family history, gender

Can be modified/treated/controlled:Can be modified/treated/controlled: SmokingSmoking Physical ActivityPhysical Activity Body mass Index: keep less than 25 (weight)Body mass Index: keep less than 25 (weight) Blood pressure: keep less than 120/80Blood pressure: keep less than 120/80 Blood glucose: keep less than 140 (random)Blood glucose: keep less than 140 (random) CholesterolCholesterol

Keep total below 200Keep total below 200 HDL, LDL, triglyceride levels HDL, LDL, triglyceride levels

ADULTSADULTS PROBLEMSPROBLEMS

Arteriosclerosis (scler/o = hardening) Arteriosclerosis (scler/o = hardening) Affects walls of small vesselsAffects walls of small vessels

Angina pectorisAngina pectoris Severe pain in chest (and may radiate)Severe pain in chest (and may radiate)

Decreased blood flow to heartDecreased blood flow to heart

Abnormalities in vesselsAbnormalities in vessels AneurysmAneurysm

Ballonlike swelling of an arteryBallonlike swelling of an artery Atherosclerosis (ather/o = pasty material) Atherosclerosis (ather/o = pasty material)

Blockage caused by lipid deposits Blockage caused by lipid deposits

SENIORSSENIORS Aging changesAging changes

Elevated BPElevated BP Normal calcification of vesselsNormal calcification of vessels

Coronary heart diseaseCoronary heart disease General termGeneral term

Congestive heart FailureCongestive heart Failure Poor pumping ability of heart – poor body Poor pumping ability of heart – poor body

perfusionperfusion Arrhythmias (rhythm = beat)Arrhythmias (rhythm = beat)

Irregular heart rhythmIrregular heart rhythm Ectopic beats (ecto = outer)Ectopic beats (ecto = outer)

Heartbeat outside regular rate and rhythm Heartbeat outside regular rate and rhythm Outside SA node regulationOutside SA node regulation

GENERAL TERMSGENERAL TERMS Bradycardia (brady = slow)Bradycardia (brady = slow)

Tachycardia (tachy = rapid)Tachycardia (tachy = rapid)

Cardiomegaly (megal/o = enlargement)Cardiomegaly (megal/o = enlargement)

Vasoconstriction Vasoconstriction Narrowing of a vesselNarrowing of a vessel

VasodilationVasodilation Widening of a vesselWidening of a vessel

Varicose VeinVaricose Vein Dilated and twisted veins, usually in legs Dilated and twisted veins, usually in legs

TESTSTESTS Blood testing Blood testing −− lipid risk panel lipid risk panel

Electrocardiogram (ECG)Electrocardiogram (ECG) Ultrasound of heartUltrasound of heart

EKGEKG Tracing electrical activity of the heartTracing electrical activity of the heart Identify heart muscle changes Identify heart muscle changes

Interpreting EKGsAn EKG is printed on paper covered with a grid of squares.Notice that five small squares on the paper form a larger square. The width of a single small square on EKG paper represents 0.04 seconds.  - A common length of an EKG printout is 6 seconds; this is known as a "six second strip."

HEART RHYTHMSHEART RHYTHMS EKG tracingsEKG tracings

PROCEDURESPROCEDURES Interventional cardiologyInterventional cardiology

Cardiac catheterization (angiogram)Cardiac catheterization (angiogram) To determine flow of blood through heart and To determine flow of blood through heart and

main vesselsmain vessels Use catheter and dyeUse catheter and dye

Balloon Angioplasty (PTCA)Balloon Angioplasty (PTCA) Balloon catheter inserted into blocked coronary Balloon catheter inserted into blocked coronary

artery, then inflated to push plaque against artery, then inflated to push plaque against vessel wallsvessel walls

EndarterectomyEndarterectomy Removal of plaque from an arteryRemoval of plaque from an artery

Common in carotidsCommon in carotids Coronary bypass graft (CABG)Coronary bypass graft (CABG)

Cardiac vessels replaced with healthy ones Cardiac vessels replaced with healthy ones

DRUGSDRUGS Improve function of heart muscleImprove function of heart muscle

Beta-blockers, antiarryhythmics, DigoxinBeta-blockers, antiarryhythmics, Digoxin

Eliminate access fluidEliminate access fluid Diuretics (Lasix) – CHFDiuretics (Lasix) – CHF

Ensure flow of blood through vesselsEnsure flow of blood through vessels AnticoagulantsAnticoagulants

Decrease blood pressureDecrease blood pressure AntihypertensivesAntihypertensives

Decrease serum cholesterol levelsDecrease serum cholesterol levels HypolipidemicsHypolipidemics