Chapter 11 CARDIOVASCULAR SYSTEM The heart is a muscle that pumps blood. Blood vessels carry the blood.

PRACTITIONERS Cardiology (cardi/o = heart) Cardiology (cardi/o = heart) Cardiologist Cardiologist Interventional cardiologist Interventional cardiologist Performs procedures and inserts devices Performs procedures and inserts devices Cardiac surgeon Cardiac surgeon Cardiovascular surgeon (vascul/o = vessel) Cardiovascular surgeon (vascul/o = vessel) Treats vessels Treats vessels

HEART FACTS Located in center of thoracic cavity Located in center of thoracic cavity Between the lungs & behind the sternum Between the lungs & behind the sternum Size of your fist Size of your fist Points (bottom, apex) left Points (bottom, apex) left Three-layered wall Three-layered wall Pericardium – outer layer of fibrous tissue Pericardium – outer layer of fibrous tissue Myocardium – middle layer of thick muscle (my/o) Myocardium – middle layer of thick muscle (my/o) Endocardium – inner layer of epithelial cells Endocardium – inner layer of epithelial cells

Anatomy & Physiology of Heart and Surrounding Structures

HEART 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 chambers 4 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 chambers Valves connect upper and lower chambers Bicuspid valve – left side (bi = two) Bicuspid valve – left side (bi = two) Also called mitral valve Also called mitral valve Tricuspid valve – right side Tricuspid valve – right side Open and close together Open and close together Prevent blood from flowing back into the atria Prevent blood from flowing back into the atria

HEART ANATOMY (con’t) 2 additional valves in ventricles 2 additional valves in ventricles Pulmonary valve –opening of pulmonary artery Pulmonary valve –opening of pulmonary artery Aortic valve –opening of the aorta Aortic 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 Valve 2. Tricuspid Valve 3. Mitral (Bicuspid) Valve 4. Aortic Valve 5. Heart Apex

Check your labels!

INTERNAL VIEW OF HEART

HEART ACTION Heart contracts to pump blood Heart 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 ventricles Contraction by atria, then ventricles Together = cardiac cycle Together = cardiac cycle Average heart beat is 72/min Average heart beat is 72/min Cardiac output = volume of blood pumped in 1 min. Cardiac output = volume of blood 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 HEART Pulmonary circulation Pulmonary circulation Right side of heart carries blood to lungs Right side of heart carries blood to lungs Return of de-oxygenated blood from the body Return of de-oxygenated blood from the body Blood flow to pick up oxygenated blood in lungs Blood flow to pick up oxygenated blood in lungs Systemic circulation Systemic circulation Left side of heart carries blood to body Left side of heart carries blood to body Oxygenated blood returns from lungs Oxygenated blood returns from lungs Oxygenated blood sent out to body cells via aorta Oxygenated blood sent out to body cells via aorta

CONDUCTION SYSTEM Works like an electrical circuit Works like an electrical circuit Signal flows from Signal flows from SA node –begins process SA node –begins process Pacemaker of heart Pacemaker of heart Determines rhythm Determines rhythm AV node AV node Right and left bundle branches (Bundle of His) Right and left bundle branches (Bundle of His) Purkinje fibers Purkinje fibers

CONDUCTION SYSTEM

Plasma (55% of the blood) Plasma (55% of the blood) A straw-colored fluid which is about 90% water and 10% dissolved gases, salts, nutrients, enzymes, hormones, waste products and plasma proteins A straw-colored fluid which is about 90% water and 10% dissolved gases, salts, nutrients, enzymes, hormones, waste 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 binds oxygen Contain hemoglobin, which is the iron-containing protein that binds oxygen WBC’s (leukocytes) (4,000-10,000) WBC’s (leukocytes) (4,000-10,000) They are the army of the circulatory system They are the army of the circulatory system May increase dramatically when the body is fighting an infection May increase dramatically when the body is fighting an infection Platelets (250,000 – 400,000) Platelets (250,000 – 400,000) Help in blood clotting by clumping together at the injury to prevent blood from flowing out of the cut Help in blood clotting by clumping together at the injury to prevent blood from flowing out of the cut Parts of the Blood

BLOOD VESSELS Vessel Vessel Vas/o Vas/o Angi/o Angi/o Arteries (arteri/o) Arteries (arteri/o) Carries blood away from the heart Carries blood away from the heart Largest artery is the aorta Largest 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 exchanged Nutrients and gases are exchanged

VESSELS (con ‘t) Venous system Venous system Carries blood back to heart Carries 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 cavae Largest = superior and inferior venae cavae Veins have one-way valves to prevent back flow of blood Veins have one-way valves to prevent back flow of blood Lumen: central opening of vessel Lumen: central opening of vessel Pulse: artery expanding and contracting Pulse: artery expanding and contracting Arterial system helps maintain body’s blood pressure: constrict and dilate to keep an even pressure gradient Arterial system helps maintain body’s blood pressure: constrict and dilate to keep an even pressure gradient

PULSE POINTS (palpable pulses)

HEART FACTS Heart has a circulatory system to nourish the heart muscle Heart has a circulatory system to nourish the heart muscle Called coronary circulation (coron/o = circle or crown) Called coronary circulation (coron/o = circle or crown) Right and left coronary arteries Right 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 BP Hypertension = Elevated BP Increased resistance in vessels – Poor blood flow Increased resistance in vessels – Poor blood flow Hypotension Hypotension 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 & ILLNESS Listen to the heart with a stethoscope Listen to the heart with a stethoscope Lub - dub = S1, S2 Lub - dub = S1, S2 S1 – closing of AV valves as ventricles contract (systole) S1 – closing of AV valves as ventricles contract (systole) S2 – closing of semilunar valves closing in relaxation diastole S2 – closing of semilunar valves closing in relaxation diastole Listen to specific areas of heart for: Listen to specific areas of heart for: Abnormal heart sounds Abnormal heart sounds Valve defects Valve defects

Heart Sounds - Opening and Closing of Valves, "Lub Dub" Stethoscope - instrument to listen and measure heart sounds

FETUSES & NEWBORNS At birth, lungs inflate and aeration begins At birth, lungs inflate and aeration begins Congenital heart defects Congenital heart defects Impaired cardiac function Impaired cardiac function ASD: opening between atrium ASD: opening between atrium VSD: opening between ventricles VSD: opening between ventricles PDA: persistent fetal circulation PDA: persistent fetal circulation Coarctation of aorta: narrowing of descending portion of aorta Coarctation of aorta: narrowing of descending portion of aorta

CHILDREN Murmurs Murmurs Innocent murmurs Innocent murmurs Functional murmurs Functional murmurs

ADULTS –Risk Factors Risk factors for heart disease Risk factors for heart disease Cannot be controlled: Cannot be controlled: Age, family history, gender Age, family history, gender Can be modified/treated/controlled: Can be modified/treated/controlled: Smoking Smoking Physical Activity Physical Activity Body mass Index: keep less than 25 (weight) Body mass Index: keep less than 25 (weight) Blood pressure: keep less than 120/80 Blood pressure: keep less than 120/80 Blood glucose: keep less than 140 (random) Blood glucose: keep less than 140 (random) Cholesterol Cholesterol Keep total below 200 Keep total below 200 HDL, LDL, triglyceride levels HDL, LDL, triglyceride levels

ADULTS PROBLEMS PROBLEMS Arteriosclerosis (scler/o = hardening) Arteriosclerosis (scler/o = hardening) Affects walls of small vessels Affects walls of small vessels Angina pectoris Angina pectoris Severe pain in chest (and may radiate) Severe pain in chest (and may radiate) Decreased blood flow to heart Decreased blood flow to heart Abnormalities in vessels Abnormalities in vessels Aneurysm Aneurysm Ballonlike swelling of an artery Ballonlike swelling of an artery Atherosclerosis (ather/o = pasty material) Atherosclerosis (ather/o = pasty material) Blockage caused by lipid deposits Blockage caused by lipid deposits

SENIORS Aging changes Aging changes Elevated BP Elevated BP Normal calcification of vessels Normal calcification of vessels Coronary heart disease Coronary heart disease General term General term Congestive heart Failure Congestive heart Failure Poor pumping ability of heart – poor body perfusion Poor pumping ability of heart – poor body perfusion Arrhythmias (rhythm = beat) Arrhythmias (rhythm = beat) Irregular heart rhythm Irregular 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 regulation Outside SA node regulation

GENERAL 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 vessel Narrowing of a vessel Vasodilation Vasodilation Widening of a vessel Widening of a vessel Varicose Vein Varicose Vein Dilated and twisted veins, usually in legs Dilated and twisted veins, usually in legs

TESTS Blood testing − lipid risk panel Blood testing − lipid risk panel Electrocardiogram (ECG) Electrocardiogram (ECG) Ultrasound of heart Ultrasound of heart EKG EKG Tracing electrical activity of the heart Tracing electrical activity of the heart Identify heart muscle changes Identify heart muscle changes

Interpreting EKGs An 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 RHYTHMS EKG tracings EKG tracings

PROCEDURES Interventional cardiology Interventional cardiology Cardiac catheterization (angiogram) Cardiac catheterization (angiogram) To determine flow of blood through heart and main vessels To determine flow of blood through heart and main vessels Use catheter and dye Use catheter and dye Balloon Angioplasty (PTCA) Balloon Angioplasty (PTCA) Balloon catheter inserted into blocked coronary artery, then inflated to push plaque against vessel walls Balloon catheter inserted into blocked coronary artery, then inflated to push plaque against vessel walls Endarterectomy Endarterectomy Removal of plaque from an artery Removal of plaque from an artery Common in carotids Common in carotids Coronary bypass graft (CABG) Coronary bypass graft (CABG) Cardiac vessels replaced with healthy ones Cardiac vessels replaced with healthy ones

DRUGS Improve function of heart muscle Improve function of heart muscle Beta-blockers, antiarryhythmics, Digoxin Beta-blockers, antiarryhythmics, Digoxin Eliminate access fluid Eliminate access fluid Diuretics (Lasix) – CHF Diuretics (Lasix) – CHF Ensure flow of blood through vessels Ensure flow of blood through vessels Anticoagulants Anticoagulants Decrease blood pressure Decrease blood pressure Antihypertensives Antihypertensives Decrease serum cholesterol levels Decrease serum cholesterol levels Hypolipidemics Hypolipidemics