The Heart A four-chambered, hollow muscular pump that circulates blood throughout the cardiovascular system. It lies slightly to the left of the midline

The Heart

• A four-chambered, hollow muscular pump that circulates blood throughout the cardiovascular system.

• It lies slightly to the left of the midline and has three linings:– Endocardium

• The inner lining of the heart.

– Myocardium• The muscular, middle layer of the heart.

– Pericardium• The outer, membranous sac surrounding the heart.

Cardiovascular System Animation

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Copyright ©2008 by Pearson Education, Inc.Pearson Prentice Hall

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Medical Terminology, 6eBy Jane Rice

Figure 9.1Tissues of the heart.

Heart Chambers Animation

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The Heart

• The heart is divided into right and left heart by a partition called the septum. Each side has an upper and lower chamber:– Atria, or upper chamber– Ventricles, or lower chambers

The Heart

• Right atrium is located at the right upper portion. It is a thin-walled space that receives blood from all body parts except the lungs.

• Two large veins, superior and inferior vena cavae, bring the blood to the right atrium.

The Heart

• Left atrium is located at the left upper portion. It receives blood rich in O2 as it returns from the lungs via the right and left pulmonary veins.

The Heart

• Right Ventricle– Located at the right lower portion, it receives blood

from the right atrium through the atrioventricular (AV) valve and pumps it through a semilunar valve to the lungs.

• Left Ventricle– Located at the left lower portion, it receives blood from

the left atrium through the atrioventricular (AV) valve and pumps it through a semilunar valve to a large artery known as the aorta and from there to all parts of the body except the lungs.

The Heart

• Heart Valves– Tricuspid or right atrioventricular– Pulmonary semilunar– Bicuspid or mitral– Aortic semilunar

The Heart

• The Tricuspid or Right Atrioventricular Valve – Guards the opening between the right atrium and right

ventricle.– The tricuspid valve allows the flow of blood into the

ventricle and prevents its return to the right atrium.• The Pulmonary Semilunar Valve

– The exit valve for blood leaving the right ventricle is located between the right ventricle and the pulmonary artery.

– It allows blood to flow from the right ventricle through the pulmonary artery to the lungs.

The Heart

• The Bicuspid or Mitral Valve– Also known as the left atrioventricular, it is located

between the left atrium and left ventricle.– It allows blood to flow to the left ventricle and

closes to prevent its return to the left atrium.

The Heart

• The Aortic Semilunar Valve– The exit point for blood leaving the left ventricle is

located between the left ventricle and the aorta.– It allows blood to flow into the aorta and prevents

its return to the ventricle.




Figure 9.2Valves of the heart.

Fetal Heart Development Animation

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Figure 9.3Coronary circulation. (A) Coronary vessels portraying the complexity and extent of the coronary circulation. (B) Coronary vessels that supply the anterior surface of the heart.




Figure 9.3Coronary circulation. (A) Coronary vessels portraying the complexity and extent of the coronary circulation. (B) Coronary vessels that supply the anterior surface of the heart.

Vascular System of the Heart

• The heart has its own vascular system.• The coronary arteries supply the heart with

blood, and the coronary veins, draining into the coronary sinus, collecting the blood and returning it to the right atrium.




Figure 9.4The functioning of the heart valves and blood flow.

The Flow of Blood

• Blood flows through the heart, to the lungs, back to the heart, and to various parts of the body.

• http://www.youtube.com/watch?v=AbmWLXpL0Aw

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The Flow of Blood

• Blood from the superior and inferior vena cavae enters the right atrium.

• Blood passes through the tricuspid valve into the right ventricle.

• Right ventricle pumps blood through the pulmonary semilunar valve into the left and right pulmonary arteries.

The Flow of Blood

• Pulmonary arteries carry blood to the lungs where the blood gives up waste and takes on O2 as it passes through capillaries (microscopic blood vessels with thin walls that allow the passage of O2 and nutrients to the body and lets the blood pick up waste and CO2) and into veins.

The Flow of Blood

• Blood leaves lungs through the left and right pulmonary veins carrying it to the left atrium.

The Flow of Blood

• The oxygenated blood passes through the bicuspid or mitral valve into the left ventricle.

• The blood is pumped through the aortic valve and into the aorta.

• The aorta supplies a branching system of smaller arteries that connects to tiny capillaries throughout the body.

Cardiac Cycle Animation 4

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Heartbeat

• The heartbeat is controlled by the autonomic nervous system and is generated by specialized neuromuscular tissue of the heart.

• The average heartbeat (pulse) is between 60 and 100 beats per minute for the average adult.

• The heart rate may be affected by emotions, smoking, disease, body size, age, stress, the environment, and many other factors.

Heartbeat

• Sinoatrial Node (SA Node)– Also known as the pacemaker of the heart, is

located the upper chamber of the right atrium, just below the opening of the superior vena cava.

– It consists of a dense network of Purkinje fibers (atypical muscle fibers), considered to be the source of the impulses initiating the heartbeat.

– Electrical impulses discharged by the SA node are distributed to the right and left atria and cause them to contract.

Heartbeat

• Atrioventricular Node (AV Node)– Located beneath the endocardium of the right

atrium, the AV node transmits electrical impulses to the bundle of His.

– Extends from the AV node into the intraventricular septum, where it divides into two branches within the two ventricles. The Purkinje fibers include the bundle of His and the peripheral fibers, which end in the ventricular muscles, where the excitation of the muscle is initiated, causing contraction.

Electrocardiogram(ECG or EKG)

• Record of the electrical activity of the heart, which provides valuable information in the diagnosing of cardiac abnormalities.

Electrocardiogram Video

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Figure 9.5Conduction system of the heart.




Figure 9.6Electrocardiogram (ECG [EKG]).

• Normal ekg http://www.youtube.com/watch?NR=1&v=7N4viIanngg&feature=fvwp

• Cardiac arrest– http://www.youtube.com/watch?v=_

F3HGwpL7uY&feature=related• Congestive heart failure

– http://www.youtube.com/watch?feature=fvwp&v=GnpLm9fzYxU&NR=1

• Real beating heart– http://www.youtube.com/watch?v=Gnv54V8Jj1U

http://www.youtube.com/watch?NR=1&v=7N4viIanngg&feature=fvwp



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http://www.youtube.com/watch?v=Gnv54V8Jj1U




Figure 9.7Major arteries of the systemic circulation.

Arteries

• Consist of a branching system of vessels that transport blood from the right and left ventricles of the heart to all body parts.

• All arteries have a pulse, which reflects the rhythmical beating of the heart.

Arteries

• Following is a list of points commonly used to check the rate, rhythm, and condition of arterial walls:– Radial– Brachial– Carotid– Temporal– Femoral– Popliteal– Dorsalis pedis




Figure 9.8Primary pulse points of the body.

Upper Limb Arteries Animation

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Lower Limb Arteries Animation

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Blood Pressure

• The pressure exerted by the blood on the wall of the vessels.

• The term most commonly refers to the pressure exerted in large arteries at the peak of the pulse wave.

• Sphygmomanometer• Stethoscope




Figure 9.9Blood pressure measurement.

Blood Pressure Measurement Video

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Veins

• The vessels that transport blood from the peripheral tissue and from the lungs to the heart.




Figure 9.10Major veins of the systemic circulation.

Capillaries

• Microscopic blood vessels with single-celled walls that connect arterioles (small arteries) with venules (small veins).

Capillaries

• Blood passing through capillaries gives up O2 and nutrients carried to this point by arteries and picks up waste and CO2 as it enters veins.

Capillary Pressure Animation

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Life Span Considerations:The Child

• Development of the fetal heart is usually completed during the first two months of gestation.

• It is completely formed and functioning by 10 weeks.

• Most congenital heart defects develop before the 10th week of pregnancy.

• If using a fetoscope, the fetal heart can be heard at 16 weeks.

Life Span Considerations:The Child

• Oxygen is received by the fetus through fetal circulation and discontinues when the umbilicus is clamped.

• Pulse, blood pressure, and respiration will vary according to age.

Congenital Heart Defects Animation

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Life Span Considerations:The Older Adult

• Lifestyles have a direct effect on the circulatory system of the older individual.

• The normal aging heart is able to provide an adequate cardiac output.

• In some older adults, the heart must work harder to pump blood because of:– Arteriosclerosis– Atherosclerosis– Heart failure




Figure 9.11Signs and symptoms of a patient with heart failure.




Figure 9.12Multisystem effects of heart failure.

• Medical Words and Definitions with Word Parts

• These terms (shown in black in the Building Your Medical Vocabulary feature) can be analyzed and defined by dividing them into component parts.

1. Prefixes (P)2. Roots (R)3. Combining Forms (CF)4. Suffixes (S)

Building Your Medical Vocabulary

• Medical Words and Definitions without Word Parts• These terms (shown in pink in the Building Your Medical Vocabulary feature)

are not usually analyzed and defined by dividing them into component parts.

Building Your Medical Vocabulary




Figure 9.13Abdominal aortic aneurysm.




Figure 9.14Infarction angioma. (Courtesy of Jason L. Smith, MD)




Figure 9.15 Temporal arteritis. (Courtesy of Jason L. Smith, MD)




Figure 9.16A permanent epicardial pacemaker. The pulse generator can be placed in subcutaneous pockets in the subclavian or abdominal regions.




Figure 9.17Schematic of an automated external defibrillator (AED) attached to a patient.




Figure 9.18Cardiomyopathy.




Figure 9.19Defibrillator (cardioverter).




Figure 9.20How microorganisms enter bloodstream and affect heart lesions, which could result in bacterial endocarditis.




Figure 9.21Hemangioma. (Courtesy of Jason L. Smith, MD)




Figure 9.22Sclerosing hemangioma. (Courtesy of Jason L. Smith, MD)




Figure 9.23Pulse oximetry with the sensor probe applied securely, flush with skin, making sure that both sensor probes are aligned directly opposite each other.




Figure 9.24Balloon angioplasty. (A) The balloon catheter is threaded into the affected coronary artery. (B) The balloon is positioned across the area of obstruction. (C) The balloon is then inflated, flattening the plaque against the arterial wall (D).




Figure 9.25Pericardiocentesis.




Figure 9.26Raynaud’s phenomenon. (Courtesy of Jason L. Smith, MD)




Figure 9.27Symptoms of a patient in shock.




Figure 9.28Placement of a balloon expandable intracoronary stent. (A) The stainless steel stent is fitted over a balloon-tipped catheter. (B) The stent is positioned along the blockage and expanded. (C) The balloon is deflated and removed, leaving the stent

in place.




Figure 9.29Telangiectasis. (Courtesy of Jason L. Smith, MD)




Figure 9.30Thrombophlebitis. (Courtesy of Jason L. Smith, MD)




Figure 9.31Thrombus formation in an atherosclerotic vessel depicting: (A) the initial clot formation, and (B) and (C) the varying degrees of occlusion.




Figure 9.32Development of varicose veins.

Coronary Heart Disease

• Is the most common form of heart disease and is also referred to as Coronary Artery Disease (CAD).

• There is narrowing of coronary arteries that supply blood to the heart.

• It is a progressive disease that increases the risk of myocardial infarction (MI) and sudden death.


• Symptoms may include:– Angina or chest pain.– Chest pain may radiate to the neck, jaw, or left

arm.– Shortness of breath (SOB) signifying heart failure.


• Coronary heart disease is the leading cause of death in the United States for men and women.


• Conditions that contribute to CHD include:– Atherosclerosis.– Combination of unhealthy lifestyle choices and

genetics.– High levels of VLDL and LDL lipoproteins are

associated with cholesterol and triglyceride deposits in arteries.

– Obesity.– Diabetes mellitus.– Hypertension.

Coronary Heart Disease Video

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Figure 9.34Blood vessels: (A) normal artery, (B) constriction, and (C) arteriosclerosis and atherosclerosis.




Figure 9.35Atherosclerotic artery.




Peripheral Artery Disease

• A condition in which fatty deposits build up in the inner linings of the artery walls.

• The blockages restrict blood circulation, mainly in arteries leading to the kidneys, stomach, arms, legs, and feet.

Peripheral Artery Disease

• Symptoms include:– Claudication: dull cramping pain in the hips,

thighs, calves, or buttocks.– Numbness or tingling in the leg, foot, or toes– Impotence– Sores or infections that do not heal– Weakness in legs or arms

Dysrhythmia

• An abnormality of the rhythm or rate of the heartbeat.

• It is caused by a disturbance of the normal electrical activity within the heart.

Dysrhythmia

• The symptoms of dysrhythmias can include:– Dizziness– Palpitations– Shortness of breath– Fatigue– Weakness– Angina– Fainting

Dysrhythmia

• Most are caused by heart disease such as endocarditis and heart failure.

• They can be life threatening if they decrease the pumping action of the heart.

• There are two types:– Tachycardias: rapid heartbeat of over 100

beats/minute.– Bradycardias: slow heartbeat of less than 60

beats/minute.

Dysrhythmia Video

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Hypertension

• Known as the silent killer, describes blood pressure higher than normal.

• With HBP, the blood vessels can become tight and constricted, causing the blood to press on the vessel walls with extra force.

Hypertension

• Hypertension can be controlled by:– Taking BP medication as prescribed– Establishing healthy eating habits– Exercising– Avoiding stress– Making lifestyle changes– Regular check-ups







Figure 9.36Uncontrolled hypertension can lead to stroke, eye damage, heart attack, kidney failure, and peripheral artery disease.

Prehypertension

• Individuals aged 18 years and over with blood pressure ranging from 120/80 to 139/89 mmHg.

• Adults at the upper end of prehypertension are twice as likely to proceed to hypertension as those with lower blood pressure levels.

• Lifestyle and dietary modifications are critical in the prevention of high blood pressure.

Heart Attack

• Occurs when the blood supply to part of the myocardium is severely reduced or stopped.

• The plaque can eventually tear or rupture, triggering a blood clot that blocks the artery and leads to a heart attack.

• Such an event is called a coronary thrombosis or coronary occlusion.

• The most common symptom of a heart attack is chest pain or angina.

Heart Attack

• The warning signs of a heart attack include:– Pressure, fullness, squeezing pain in the center of

the chest that last for 2 minutes or longer.– Pain that spreads to the shoulders, neck, or arms.– Dizziness, fainting, sweating, nausea, or shortness

of breath.

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The Heart A four-chambered, hollow muscular pump that circulates blood throughout the cardiovascular system. It lies slightly to the left of the midline