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Chapter 30 The Circulatory System Copyright ©2012 Delmar, Cengage Learning. All rights reserved. 4 Main Parts of the Circulatory System 1. The heart – Acts like a pump 2. The blood vessels – Act like the plumbing 3. The blood – The circulating fluid 4. The lymphatic system – Acts to provide auxiliary fluid Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Anatomy of the Heart • Located behind the sternum and in between the lungs • Two-thirds of the heart is on the left side of the chest • The heart is about the size of a clenched fist • The tricuspid valve is located between the right atrium and ventricle Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Internal Heart Structures Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The External Heart Structures Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Heart Sounds • The lubb-dupp sounds – Lubb • First sound • Caused by the valves slamming shut – Dupp • Second sound • Caused by the closure of the semilunar valves Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Pacemaker of the Heart • A specialized group of nerve cells located in the right atrium is called the sinoatrial (SA) node or the “pacemaker.” • These cells generates the electrical impulse that starts the wave of muscle contractions in the heart. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. 5 Types of Blood Vessels 1. Arteries – Vessels throughout the body that expand and contract as they carry fresh, oxygenated blood away from the heart – The only exception is the pulmonary artery, which carries deoxygenated blood to the lungs. 2. Arterioles – Connect arteries to capillaries Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Major Arteries of the Body Copyright ©2012 Delmar, Cengage Learning. All rights reserved. 5 Types of Blood Vessels 3.Capillaries – Thin walls and have are one cell structures – Oxygen-rich blood enters the capillary bed, where the exchange of gasses occurs. – When blood leaves the capillary bed, it carries away carbon dioxide and waste. – Capillary beds reduce the rate of blood flow and allow oxygen and nutrients to enter the tissue cells in exchange for carbon dioxide and waste. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. 5 Types of Blood Vessels 4.Veins – Similar to arteries, but the walls are thinner and they lack elastic fibers – Veins carry deoxygenated blood back to the heart – Exception: The pulmonary veins return oxygenated blood from the lungs to the heart. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Major Veins of the Body Copyright ©2012 Delmar, Cengage Learning. All rights reserved. 5 Types of Blood Vessels 5. Venules – Join together with the capillaries to form veins that eventually enter the heart through the vena cava Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Portal Circulation Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Portal Circulation 1. Arteries branch off the aorta as it descends to the internal organs. 2. Each organ then receives the substances on which it reacts. 3. These substances can be sugar, salt, hormones, chemicals, nutrients, or waste. 4. Everything you eat, drink, inhale, or inject enters the circulatory system. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Pathway of Blood through the Pulmonary Circulation Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Pathway of Blood through the Systemic Circulation 1. Blood leaves the left ventricle and enters the aorta. 2. Blood travels throughout the body in the aorta. 3. The aorta divides at the fourth lumbar vertebra. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Pathway of Blood through the Systemic Circulation 4. The external branch becomes the femoral artery and continues down the leg. 5. The arteries become arterioles and join the capillaries. 6. Deoxygenated blood leaves the capillaries and enters the venules and veins. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Pathway of Blood through the Systemic Circulation 7. The major veins of the lower extremities join with the inferior vena cava. 8. The major veins of the upper extremities join with the superior vena cava. 9.The superior and inferior vena cava empty into the right atrium of the heart. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Structure of the Lymphatic System • The lymphatic system is made up of: – Lymph nodes – Lymph (a straw-colored fluid) – Lymph vessels – Spleen – Lymph tissue – Tonsils – Thymus gland Lymph fills the spaces between the cells, acts as a bridge between cells and capillaries, and contains blood plasma. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. • Adenitis- Lymph nodes become swollen • Bradycardiaconsistently slow heart rate • Spleen is located just beneath the left side of the diaphragm Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Components of Whole Blood and Their Roles • Red blood cells (RBCs) – Erythrocytes – Contain hemoglobin which gives blood its red color – Hemoglobin attracts and carries oxygen and carbon dioxide in the blood. – Erythrocytes live about 4 months. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Components of Whole Blood Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Components of Whole Blood and Their Roles • Plasma – Serum globin in blood plasma assists in the formation of antibodies • White blood cells (WBCs) – Leukocytes – Leukocytes play a vital role in defending the body against invasion by chasing down bacteria. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Components of Whole Blood and Their Roles • Granulocytes are white blood cells produced in the red bone marrow. • There are three types: – Neutrophils – Eosinophils – Basophils Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Components of Whole Blood and Their Roles • Neutrophils – Surround, swallow, and digest bacteria • Eosinophils – Respond to allergic reactions or parasites • Basophils – Respond to chronic infection Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Components of Whole Blood and Their Roles • Agranulocytes – White blood cells produced by bone marrow and lymph tissue that break down into two types: 1. Lymphocytes produce immunity by developing antibodies and attaching to and destroying foreign bodies. 2. Monocytes eat and destroy bacteria. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Components of Whole Blood and Their Roles • Platelets – Thrombocytes – Smallest of the three cells – Formed in the bone marrow from cell fragments – Platelets function in the process of clotting blood Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Clotting Process 1. The cut vessel attracts or catches platelets. 2. Platelets form a small mass at the cut. 3. Platelets release a chemical that causes the vessel to narrow and decreases blood loss until a clot forms. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Clotting Process 4.Platelets and the injured tissue release thromboplastin, which begins to create a reaction that forms a network of fine mesh fibers over the cut. 5.This net catches the red blood cells, platelets, and plasma and forms the clot. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Blood Types and Their Importance • Blood types are determined by the presence of a protein factor, called an antigen, on the surface of the red blood cell. • There are 4 types of blood: 1.A 2.B 3.AB- Universal recipient 4.O- Universal donor Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Blood Types and Their Importance • Blood plasma also has a protein substance, called an antibody, that reacts to the protein on the surface of the blood cell. • Blood clumps and forms clots if antigens and antibodies of the same type come together. • During blood transfusions, determining the blood type can prevent this reaction. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. The Importance of the Rh Factor • Originally detected in, and named after, the Rhesus monkey • An antigen that may or may not be present in the red blood cell (Rh + or Rh -) • If a person without the antigen receives blood with the antigen, the body produces antibodies that can cause serious complications. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Arteriography • X-ray examination of the arteries after injection of a contrast medium • This test indicates the status of blood flow, aneurysms, or the presence of hemorrhage. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Cardiac Catheterization • A catheter is inserted into the brachial or femoral artery and is passed up into the heart. • A contrast medium is injected into the catheter to permit visualization of the heart chambers, valves, and pulmonary and coronary arteries. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Doppler Ultrasonography • Sound waves are transmitted through the skin and are reflected by blood cells moving through the blood vessels. • This test evaluates blood vessels and can diagnose deep vein thrombosis, aneurysms, and arterial blockages. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Echocardiograph • Uses high-frequency sound waves to make images of the internal heart structures. • This test evaluates cardiac function, the condition of the heart valves, defects in the heart walls, and the presence of fluid between layers of the pericardium. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Electrocardiograph • Abbreviated EKG or ECG • Provides a graphic recording of the electrical activity of the heart • This test identifies heart rhythms and provides a method of detecting the progression of cardiac disease Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Holter Monitor • An ambulatory EKG that records heart activity over a 24-hour period. • This test helps to evaluate symptoms that occur irregularly. • This test can also evaluate the status of recovering cardiac patients. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Heart Scan • Computerized CT scan that sweeps electron beams so fast that it freezes the beating motion of the heart. • This test diagnoses the presence of plaque and coronary occlusion. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. MUGA SCAN • Multiple-gated acquisition scan • After isotopes are injected into the vein and taken up by the myocardium, a camera records the motion of the heart. • This test evaluates the condition of the myocardium. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Myocardial Perfusion Imaging • This test measures the passage of blood through the coronary arteries to the myocardium. • The blood vessels are dilated and a radioactive material is injected. • This material concentrates in the areas of the myocardium with good blood flow. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Venogram • X-ray studies using a contrast medium to determine the condition of the deep veins of the legs Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Anemia • Term used to indicate elements that are lacking in the blood • Iron-deficiency anemia – Lack of iron • Aplastic anemia – Injury or destruction of blood cell formation by the bone marrow • Blood loss anemia – Condition of low red blood cell count occurring over an extended period of time Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Aneurysm • Ballooning out of the wall of an artery • Often associated with atherosclerosis or arteriosclerosis • Cerebral aneurysms – Occur in the brain • Thoracic aneurysms – Occur in the chest • Abdominal aneurysms – Occur in the abdomen Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Angina • Severe chest pain that radiates down the inner surface of the left arm • Usually associated with emotional stress or physical exertion • May last from a few seconds to several minutes Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Cardiac Arrest • Complete, sudden cessation of heart action • Rapidly fatal • Produces brain damage after 5 minutes Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Arrhythmia • Any abnormal changes in the heart rhythm • Can range from mild to life threatening • Classified according to the origin (e.g., atria) or the irregularity (e.g., premature, fibrillation) Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Arteriosclerosis • “Hardening” of the arteries and arterioles • Causes: Muscular and elastic tissue is replaced by fibrous tissue and calcification. • The heart must exert more pressure because the vessels no longer expand and recoil with each heartbeat. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Atherosclerosis • The development of fatty material along the lining of the arteries. • The openings of the arteries may be partially or completely blocked, reducing or eliminating blood flow to the area. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Athletic Heart Syndrome • Cardiac changes that occur as a result of strenuous exercise • The heart enlarges, especially the ventricles, because of the need for increased output. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Carditis • Inflammation of the heart • Results from an infectious process caused by the invasion of a virus, fungus, or bacterial pathogen Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Cerebrovascular Accident • Sudden impairment of the flow of blood to the brain that interrupts the flow of oxygen and causes damage or destruction to brain tissue • Commonly called a stroke Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Congestive Heart Failure • A group of cardiac dysfunctions that results in poor performance of the heart with related congestion of the circulatory system • This disorder can be a complication of coronary artery disease. • The myocardium of the left ventricle is most commonly affected. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Coronary Artery Disease • A disease of the arteries that surround the heart and carry oxygen and nutrients to the myocardium • Causes angina-like symptoms, nausea, vomiting, fainting, and perspiration Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Embolism • Foreign matter that enters and circulates in the bloodstream • This matter can be made up of blood, exudate, fat, or air. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Heart Failure • A condition, particularly with the aged, in which the heart pumps too weakly to supply the body with blood. • Severe failure shortens life expectancy. • Heart transplant may be one treatment option. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Heart Replacement • The diseased heart is removed and replaced with a healthy donor heart after much physical, financial, legal, emotional, and ethical preparation. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Hypertension • Blood pressure readings consistently above 140/90 • Foremost contributing factor to stroke and kidney damage • Essential – No known cause for the elevation • Secondary – Elevation is the result of disease. • Benign – The increase occurs over a long time period. • Malignant – Rapid, severe increase Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Hypertrophic Cardiomyopathy • Results in thickening of the walls of the ventricles in the heart (markedly thickened) • The heart becomes stiff and cannot fill with blood or pump efficiently. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Hypotension • Blood pressure that results in readings below the normal range • Hypotension may become life threatening when blood circulation becomes impaired and gas exchange is inadequate. • Poor diet is not a common cause of hypotension. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Leukemia • Malignant disease of the bone marrow or lymph tissue • Leukemia can be present in an acute or chronic form Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Murmur • Abnormal sounds made by blood leaking through a heart valve; can be heard with a stethoscope • The murmur is named for the valve that is leaking. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Myocardial Infarction • Also called a “heart attack” • A complication of coronary artery disease that results from partial or complete blockage of the artery and causes destruction of myocardial tissue. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. How to Recognize a Heart Attack • A sensation of uncomfortable pressure, fullness, squeezing, aching, or pain, usually in the center of the chest • Pain, aching, or heaviness in the shoulders, neck, jaw, arms, or upper back, or spreading to the chest • Pain accompanied by lightheadedness, fainting, sweating, nausea, vomiting, or shortness of breath Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Phlebitis • Localized inflammation of a vein that causes an alteration of the epithelial lining; is likely to form a blood clot Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Sickle Cell Anemia • Congenital form of anemia that occurs primarily among African Americans • Red blood cells have a hemoglobin defect in their molecular structure that causes the cell to become sickle shaped. • These cells, which carry oxygen, cannot easily pass through blood vessels. • Inherited condition due to an autosomal recessive trait Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Stasis Ulcer • A secondary condition resulting from chronic venous insufficiency • Causes redness, swelling, scaling, cracks in the skin, and ulcers • The most common site for stasis ulcers is the ankles. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Thrombophlebitis • An acute condition that results from inflammation of the vein walls and the formation of a blood clot (thrombus) • Usually develops in superficial veins, but deep vein thrombosis can affect small or large veins; the clot interrupts blood flow and can break off and become an embolus Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Varicosities • The result of veins that have become dilated or twisted, and are inefficient • Usually results from weakness of the valves • This weakness permits blood to leak backward and causes dilation of the vessel. Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Definitions to know • • • • • Tachycardia- Consistently fast heart rate Bradycardia- Consistently slow heart rate Systole- contraction phase of a heart beat Diastole- relaxation phase of a heart beat Defibrillator- device used to discharge a strong electrical current into a patient’s heart through electrode paddles held against the bare chest wall • Premature atrial contractions (PACs)- cause the atria to contract ahead of the anticipated time • Premature junctional contractions (PJCs)- these have the ectopic pacemaker focused at the junction of the AV node and the bundle of His Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Cont. • Premature ventricular contractions (PVC)- originate in the ventricle and cause contraction ahead of the next anticipated beat • Low- density lipoprotein- “bad” cholesterol • High- density lipoprotein- “good” cholesterol • Stasis- stagnation of blood • Stent- stainless steel mesh tube commonly used with a balloon catheter to prop open a coronary artery • Benign- form of hypertension in which the blood pressure rises moderately over a fairly long period • Infarction- interference with circulation Copyright ©2012 Delmar, Cengage Learning. All rights reserved. One more full of definitions • Transient ischemic attack- small, temporary interruption of blood flow, also known as a warning sign • Stenotic- refers to a leaking valve • Hemorrhagic stroke- stroke in which a blood vessel ruptures, and the escaping blood damages brain tissue either by pressure against it or from lack of circulation through the tissue • Malignant- form of hypertension in which blood pressure rises rapidly and severely, and may not respond to treatment • Regurgitate- backward flow of blood into the left atrium Copyright ©2012 Delmar, Cengage Learning. All rights reserved. Locations • Know the location of each major vein; jugular, femoral, pulmonary, cephalic, brachial, tibial, inferior vena cava, superior vena cava, saphenous, common iliac – Jugular- from the head and neck – Femoral- in the thigh from the knee into the pelvis – Pulmonary- from the lungs to the left atrium of the heart Copyright ©2012 Delmar, Cengage Learning. All rights reserved.