Medical Terminology. Chapter 5: The Cardiovascular System

Transcription

1 Medical Terminology Chapter 5: The Cardiovascular System

2 CHAPTER OBJECTIVES This chapter covers the cardiovascular system, which is the body s delivery service, and the combining terms and abbreviations used in the building words that relate to it. Upon completion of this chapter, you should be able to: Name the parts of the cardiovascular system and discuss their function Define combining forms used in building words that relate to the cardiovascular system Identify the meaning of abbreviations Name the common diagnoses, laboratory tests and clinical procedures used in treating the cardiovascular system Define the major pathological conditions, surgical terms and pharmacological agents relating to the cardiovascular system

3 INTRODUCTION The heart and circulatory system make up your cardiovascular system. Your heart works as a pump that pushes blood to the organs, tissues, and cells of your body. Blood delivers oxygen and nutrients to every cell and removes the carbon dioxide and waste products made by those cells. Blood is carried from your heart to the rest of your body through a complex network of arteries, arterioles, and capillaries. Blood is returned to your heart through venules and veins. As in the adult, survival of the developing embryo depends on the circulation of blood to maintain homeostasis and a favorable cellular environment. In response to this need, the cardiovascular system makes its appearance early in development and reaches a functional state long before any other major organ system. Incredible as it seems, the primitive heart begins to beat regularly early in the fourth week following fertilization. The vital role of the cardiovascular system in maintaining homeostasis depends on the continuous and controlled movement of blood through the thousands of miles of capillaries that permeate every tissue and reach every cell in the body. It is in the microscopic capillaries that blood performs its ultimate transport function. Nutrients and other essential materials pass from capillary blood into fluids surrounding the cells as waste products are removed.

4 Numerous control mechanisms help to regulate and integrate the diverse functions and component parts of the cardiovascular system in order to supply blood to specific body areas according to need. These mechanisms ensure a constant internal environment surrounding each body cell regardless of differing demands for nutrients or production of waste products. Role of the circulatory system in relation to other systems. Click image to enlarge. Image Source: OpenStax College, Anatomy & Physiology. OpenStax College.

5 THE HEART The heart is a muscular pump that provides the force necessary to circulate the blood to all the tissues in the body. Its function is vital because, to survive, the tissues need a continuous supply of oxygen and nutrients, and metabolic waste products have to be removed. Deprived of these necessities, cells soon undergo irreversible changes that lead to death. While blood is the transport medium, the heart is the organ that keeps the blood moving through the vessels. The normal adult heart pumps about 5 liters of blood every minute throughout life. If it loses its pumping effectiveness for even a few minutes, the individual's life is jeopardized. STRUCTURE OF THE HEART The human heart is a four-chambered muscular organ, shaped and sized roughly like a man's closed fist with two-thirds of the mass to the left of midline. It is enclosed in a pericardial sac that is lined with the parietal layers of a serous membrane. The visceral layer of the serous membrane forms the epicardium. Three layers of tissue form the heart wall. The outer layer of the heart wall is the epicardium, the middle layer is the myocardium, and the inner layer is the endocardium.

6 The internal cavity of the heart is divided into four chambers: Right atrium Right ventricle Left atrium Left ventricle The two atria are thin-walled chambers that receive blood from the veins. The two ventricles are thickwalled chambers that forcefully pump blood out of the heart. Differences in thickness of the heart chamber walls are due to variations in the amount of myocardium present, which reflects the amount of force each chamber is required to generate. The right atrium receives deoxygenated blood from systemic veins; the left atrium receives oxygenated blood from the pulmonary veins. Link to Learning: Please watch the following video: MedlinePlus: heartbeat, then, explore the heart with this interactive activity: Texas Heart Institute: Anatomy of the Human Heart. Image Source: Wikimedia Diagram of the human heart

7 VALVES OF THE HEART Pumps need a set of valves to keep the fluid flowing in one direction and the heart is no exception. The heart has two types of valves that keep the blood flowing in the correct direction. The valves between the atria and ventricles are called atrioventricular valves (also called cuspid valves), while those at the bases of the large vessels leaving the ventricles are called semilunar valves. The right atrioventricular valve is the tricuspid valve. The left atrioventricular valve is the bicuspid, or mitral, valve. The valve between the right ventricle and pulmonary trunk is the pulmonary semilunar valve. The valve between the left ventricle and the aorta is the aortic semilunar valve. When the ventricles contract, atrioventricular valves close to prevent blood from flowing back into the atria. When the ventricles relax, semilunar valves close to prevent blood from flowing back into the ventricles. While it is convenient to describe the flow of blood through the right side of the heart and then through the left side, it is important to realize that both atria and ventricles contract at the same time. The heart works as two pumps, one on the right and one on the left, working simultaneously. Blood flows from the right atrium to the right ventricle, and then is pumped to the lungs to receive oxygen. From the lungs, the blood flows to the left atrium, then to the left ventricle. From there it is pumped to the systemic circulation.

8 Link to learning: Review the following educational poster, An Incredible Machine: The Valves of the Heart, created by the Texas Heart Institute then explore this interactive demonstration, Heart Valves. CIRCULATORY PATHWAYS Blood is carried through the body via blood vessels. An artery is a blood vessel that carries blood away from the heart, where it branches into ever-smaller vessels. Eventually, the smallest arteries, vessels called arterioles, further branch into tiny capillaries, where nutrients and wastes are exchanged, and then combine with other vessels that exit capillaries to form venules, small blood vessels that carry blood to a vein, a larger blood vessel that returns blood to the heart. Arteries and veins transport blood in two distinct circuits: the systemic circuit and the pulmonary circuit. Systemic arteries provide blood rich in oxygen to the body s tissues. The blood returned to the heart through systemic veins has less oxygen, since much of the oxygen carried by the arteries has been delivered to the cells. In contrast, in the pulmonary circuit, arteries carry blood low in oxygen exclusively to the lungs for gas exchange. Pulmonary veins then return freshly oxygenated blood from the lungs to the heart to be pumped back out into systemic circulation.

9 Coronary circulation is the circulation of blood in the blood vessels of the heart muscle (myocardium). The vessels that deliver oxygenrich blood to the myocardium are known as coronary arteries, which branch off the aorta (the largest artery). The vessels that remove the deoxygenated blood from the heart muscle are known as cardiac veins. Link Learning: Please read, Classification and Structure of Blood Vessels watch the following interactive demonstration, Circulatory System, created by the Texas Heart Institution. Image Source: OpenStax College, Anatomy & Physiology. OpenStax College.

10 Click each image to enlarge. Major Veins of the Systemic System Major Arteries of the Systemic System Link Learning: Please read Circulatory Pathways. Image Source: OpenStax College, Anatomy & Physiology. OpenStax College.

11 Please watch the following video by Mayo Clinic, Heart and the Circulatory System How they Work, for an overview on what you have learned.

12 BLOOD PRESSURE Blood pressure is the force exerted by blood upon the walls of the blood vessels or the chambers of the heart. Blood pressure may be measured in capillaries and veins, as well as the vessels of the pulmonary circulation; however, the term blood pressure without any specific descriptors typically refers to systemic arterial blood pressure that is, the pressure of blood flowing in the arteries of the systemic circulation. In clinical practice, this pressure is measured in mm Hg and is usually obtained using the brachial artery of the arm. When systemic arterial blood pressure is measured, it is recorded as a ratio of two numbers (e.g., 120/80 is a normal adult blood pressure), expressed as systolic pressure over diastolic pressure. The systolic pressure is the higher value (typically around 120 mm Hg) and reflects the arterial pressure resulting from the ejection of blood during ventricular contraction, or systole. The diastolic pressure is the lower value (usually about 80 mm Hg) and represents the arterial pressure of blood during ventricular relaxation, or diastole. The difference between the systolic pressure and the diastolic pressure is the pulse pressure. Example: An individual with a systolic pressure of 120 mm Hg and a diastolic pressure of 80 mm Hg would have a pulse pressure of 40 mmhg. Generally, a pulse pressure should be at least 25 percent of the systolic pressure. A pulse pressure below this level is described as low or narrow. Link Learning: Please watch the following video: MedlinePlus: Blood Pressure.

13 ELECTRICAL SYSTEM OF THE HEART A heart's electrical system, also called the cardiac conduction system, controls all the events that occur when your heart pumps blood. Electrical impulses from your heart muscle (the myocardium) cause your heart to contract (beat). This electrical signal begins in the sinoatrial (SA) node, located at the top of the right atrium. The SA node is sometimes called the heart's "natural pacemaker." An electrical impulse from this natural pacemaker travels through the muscle fibers of the atria and ventricles, causing them to contract. Although the SA node sends electrical impulses at a certain rate, your heart rate may still change depending on physical demands, stress, or hormonal factors. Click Image to Enlarge Image Source: OpenStax College, Anatomy & Physiology. OpenStax College.

14 The components of the cardiac conduction system include the sinoatrial node, the atrioventricular node, the atrioventricular bundle (also called bundle of His), the atrioventricular bundle branches, and the Purkinje cells. The contractions of the heart take place in the myocardium and cycle through polarization (resting state) to depolarization (contraction state) to repolarization (recharging state). Link to Learning: Please watch the following animations and read the associated material provided by: National Heart, Lung, and Blood Institute: Heart Contraction and Blood Flow and Your Heart s Electrical System. FETAL CIRCULATION In a developing embryo, the heart has developed enough by day 21 post-fertilization to begin beating and circulation patterns are clearly established by the fourth week of embryonic life. It is critical to the survival of the developing human that the circulatory system forms early to supply the growing tissue with nutrients and gases, and to remove waste products. Most circulatory pathways in a fetus are like those in the adult but there are some notable differences because the lungs, the gastrointestinal tract, and the kidneys are not functioning before birth. The fetus obtains its oxygen and nutrients from the mother and also depends on maternal circulation to carry away the carbon dioxide and waste products.

15 The umbilical cord contains two umbilical arteries to carry fetal blood to the placenta and one umbilical vein to carry oxygen-and-nutrient-rich blood from the placenta to the fetus. The ductus venosus is the connection from the umbilical vein to the inferior vena cava of the fetus and allows blood to bypass the immature liver in fetal circulation. The foramen ovale and ductus arteriosus are modifications that permit blood to bypass the lungs in fetal circulation. The foramen ovale is an opening in the interatrial septum that allows blood to flow from the right atrium to the left atrium. The ductus arteriosus allows for the passage of deoxygenated blood from the fetal heart to the umbilical cord to the placenta. The foramen ovale and ductus arteriosus close shortly after birth when the newborn begins to breathe. The ductus venosus becomes nonfunctional once the umbilical cord is severed. Click Image to enlarge. Image Source: OpenStax College, Anatomy & Physiology. OpenStax College.

16 Combining Forms of the Cardio Vascular System angi/o vessel ech/o reflected sound scler/o hardening angin/o to choke electr/o electricity sept/o a partition artero/o artery glyc/o sweet sphygm/o pulse ather/o fatty substance hem/o blood sten/o narrowing atri/o atrium hemangi/o blood vessel steth/o chest auscultate/o listen to isch/o to hold back thromb/o blood clot cardi/o heart lipid/o fat valvul/o valve chol/e bile lun/o moon vas/o blood vessel circulat/o circular man/o thin ven/o vein claudicate/o to limp palpit/o throbbing ventricul/o ventricle corpor/o body pericardi/o pericardium pericardi/o pericardium cyan/o dark blue phleb/o vein phleb/o vein dilat/o to widen pulmon/o lung dynam/o power rrythm/o rhythm

17 Abbreviations Relating to the Cardiovascular System ACG angiocardiography CMP cardiomyopathy LV left ventricle AcG accelerator globulin CO cardiac output LVH left ventricle hypertrophy AF atrial fibrillation CV cardiovascular MI myocardial infarction AMI acute myocardial infarction CVA cerebrovascular accident MS mitral stenosis AS aortic stenosis CVD cardiovascular disease MVP mitral valve prolapse ASHD arteriosclerotic heart disease DVT deep vein thrombosis P pulse AV atrioventricular ECG,EKG electrocardiogram PAD peripheral artery disease BP blood pressure ECHO echocardiogram RBCs red blood cells CABG coronary artery bypass graft ETT exercise tolerance test SA sinoatrial CAD coronary artery disease HBP high blood pressure SCA sudden cardiac arrest CC cardiac catheterization HDL high density lipoprotein SV stroke volume CHD coronary heart disease HF heart failure TC total cholesterol CHF coronary heart failure HgB hemoglobin tpa,tpa tissue plasminogen activator Chol cholesterol HR heart rate VLDL very low density lipoprotein CK creatine kinase HTN hypertension VSD ventricular septal defect CPK creatine phosphokinase IV intravenous VT ventricular tachycardia CLI critical limb ischemia LDH lactic dehydrogenase

18 TEST YOUR KNOWLEDGE This is a challenge question. Use the knowledge you have learned to determine the meaning of the following word. There are three different word parts to this word. A hemangioma means: a) Blood found in the spinal cord fluid b) A tumor of heart muscle c) A tumor of blood vessels d) Blood found between the brain and the skull. Answer: c) A tumor of blood vessels Click the image to check your answer.

19 DIAGNOSTIC, PROCEDURAL AND LABORATORY TERMS A cardiologist is a physician who specializes in the diagnosis and treatment of diseases of the circulatory system, especially, the heart. A cardiovascular surgeon, is a specialist who performs the actually heart surgery. A Hematologist, is a physician who specializes in diseases of the blood. Link to Learning: Please read Merck Manual: Overview of Heart and Blood Vessel Symptoms. There are many diagnostic tests that can show a doctor whether a person has cardiovascular disorder. The type of test performed will depend on a person s symptoms and medical history. During a standard physical examination, a doctor will perform some basic tests such as listening to a person s heart with a stethoscope. This is also called auscultation, the study of heart sounds, or listening to the sounds of the body through a stethoscope. A doctor may then take a person s blood pressure using a sphygmomanometer. Other common diagnostic tests include: Electrocardiogram (ECG or EKG): A test that records the electrical activity of the heart, shows abnormal rhythms (arrhythmias), and can sometimes detect heart muscle damage. A healthy person's electrocardiogram has a certain pattern. When there are changes in that pattern, your doctor can tell that there is a problem with your heart.

20 Stress test (also called exercise tolerance test ETT): A test that is given while a person walks on a treadmill in order to monitor the heart during exercise. Breathing and blood pressure rates are also monitored. These tests help doctors learn more about the structure and blood flow of the heart. Echocardiogram (also known as echo): A noninvasive test that uses sound waves to produce an image of the heart to evaluate how the heart's chambers and valves are functioning. Holter monitor: A small, portable recording device that is worn by a person to record heartbeats on tape during a period of 24 hours or longer. The impulses recorded by the monitor give a doctor a 24 hour record of a heart s electrical activity. Magnetic resonance imaging (MRI) of the heart: An imaging method that uses powerful magnets and radio waves to create pictures of the heart. This type of test may be used to evaluate the heart valves and major vessels, detect coronary artery disease, evaluate congenital defects, and detect the presence of tumors or other abnormalities. Magnetic resonance angiography (MRA) of the heart. An MRI exam of the blood vessels. Unlike traditional angiography that involves placing a tube (catheter) into the body, MRA is noninvasive.

21 Cardiac catheterization (also called coronary angiogram, or angiography). A test in which a long, thin tube (catheter) is guided through the large artery in the upper leg, and threaded into the heart. Once the catheter is in place, dye is injected through the catheter and into the heart. The movement of dye through the heart and coronary arteries is then recorded. This test aids doctors in seeing how the heart chambers and the coronary arteries are working. Doctors may also take x-rays of your heart to determine if your heart is an unusual shape or if it is larger than it should be. Link to Learning: Please read, Mayo Clinic: Blood Tests for Heart Disease, note that there are two pages to this article so you will need to click on the next button at the end of page one. PATHOLOGICAL TERMS Cardiovascular disease (CVD) is a class of diseases that involves the heart or blood vessels. The underlying mechanisms vary depending on the disease in question, however, the majority of cardiovascular disease is caused by risk factors that can be controlled, treated or modified, such as cholesterol, high blood pressure, obesity, tobacco use, lack of physical activity and diabetes.

22 Ischemic heart disease refers to problems with the circulation of blood to the heart muscle. A partial blockage of one or more of the coronary arteries can result in a lack of enough oxygenated blood (ischemia) thus causing symptoms such as angina (chest pain) and dyspnea (shortness of breath). A complete blockage of an artery causes necrosis (damage to the tissues) or a myocardial infarction, commonly known as a heart attack. Cerebrovascular disease (Stroke) refers to a problem with the circulation of blood in the blood vessels of the brain. A blockage with effects lasting less than 24 hours is referred to as a transient ischemic attack (TIA). A complete blockage with long-term effects is referred to as a cerebrovascular thrombosis (clot) or accident or a stroke. Sometimes, a blood vessel in the brain can burst resulting in long term effects. Peripheral vascular disease affects the circulation primarily in the legs. Patients with this disease typically complain of pain in their calves especially when walking. Heart failure occurs when the pumping action of the heart cannot provide enough blood to the rest of the body as it is needed. This can happen as a result of damage to the heart muscle, for example from a heart attack, or from excessive consumption of alcohol, or because of a heart muscle disease also called a cardiomyopathy. Patients with heart failure usually suffer from shortness of breath and swelling of the legs.

23 Rheumatic heart disease begins with a bacterial infection in childhood, affecting joints and heart valves. The heart problems appear many years later. Often the valves have to be replaced by an operation. Other infections can occur attacking the inner tissues of the heart including the valves (endocarditis) and the outer tissue overlying the heart (pericarditis). Congenital heart disease is a problem with the structure of the heart arising because of a birth defect. These anatomical defects can be as simple as a small hole in one of the inside walls of the heart or they can be very complex, affecting the way blood flows through the heart and lungs. Some congenital heart problems result in death unless immediately corrected by surgical intervention. Others cause disability to varying degrees and are treated by surgery later in life with correction of the problem sometimes requiring more than a single operation. Link to Learning: Please read, World Heart Federation, Cardiovascular Disease: Terms. SURGICAL TERMS Anastomosis: A surgical connection between two structures. It usually means a connection that is created between tubular structures, such as blood vessels or loops of intestine.

24 Angioplasty: a procedure to restore blood flow through the artery. Angioscopy : a medical technique for visualizing the interior of blood vessels. In this technique, a flexible fiberoptic catheter is inserted directly into an artery. Arteriotomy (or arterotomy): a medical term for an opening or cut of an artery wall. Atherectomy: surgical removal of atheroma. Balloon valvuloplasty: A procedure performed to open a narrowed heart valve using a thin tube called a catheter with a small balloon at its tip. Bypass: Blood vessels from another part of your body are used to go around, or bypass, a blocked artery. The result is that more blood and oxygen can flow to your heart again. Cardiopulmonary bypass: is a technique that temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the body. Embolectomy: the emergency surgical removal of emboli which are blocking blood circulation. Endarterectomy: surgical removal of part of the inner lining of an artery, together with any obstructive deposits.

25 Fontan procedure: It involves diverting the venous blood from the right atrium to the pulmonary arteries without passing through the morphologic right ventricle; i.e., the systemic and pulmonary circulations are placed in series with the functional single ventricle. Heart transplant: A surgery to remove a damaged or diseased heart and replace it with a healthy donor heart. Intravascular stent: a stent placed within a blood vessel to allow blood to flow freely. Phlebotomy: drawing blood from the body. PHARMACOLOGICAL TERMS Anticoagulants: Decrease the clotting (coagulating) ability of the blood. Sometimes called blood thinners, although they do not actually thin the blood. They do NOT dissolve existing blood clots. Used to treat certain blood vessel, heart and lung conditions. Antiplatelet Agents: Keep blood clots from forming by preventing blood platelets from sticking together.

26 Angiotensin-Converting Enzyme (ACE) Inhibitors: Expand blood vessels and decreases resistance by lowering levels of angiotensin II. Allow blood to flow more easily and makes the heart's work easier or more efficient. Angiotensin II Receptor Blockers: Rather than lowering levels of angiotensin II (as ACE inhibitors do) angiotensin II receptor blockers prevent this chemical from having any effects on the heart and blood vessels. This keeps blood pressure from rising. Angiotensin-Receptor Neprilysin Inhibitors (ARNIs): Neprilysin is an enzyme that breaks down natural substances in the body that open narrowed arteries. By limiting the effect of neprilysin, it increases the effects of these substances and improves artery opening and blood flow, reduces sodium (salt) retention, and decreases strain on the heart. Beta Blockers: Decrease the heart rate and cardiac output, which lowers blood pressure and makes the heart beat more slowly and with less force. Calcium Channel Blockers: Interrupt the movement of calcium into the cells of the heart and blood vessels. May decrease the heart's pumping strength and relax blood vessels.

27 Digitalis Preparations: Increase the force of the heart's contractions, which can be beneficial in heart failure and for irregular heartbeats. Diuretics: Cause the body to rid itself of excess fluids and sodium through urination. Help to relieve the heart's workload. Also decrease the buildup of fluid in the lungs and other parts of the body, such as the ankles and legs. Different diuretics remove fluid at varied rates and through different methods. Vasodilators: Relax blood vessels and increases the supply of blood and oxygen to the heart while reducing its workload. Can come in pills to be swallowed, chewable tablets and as a topical application (cream). Link to Learning: Please read, American Heart Association, Cardiac Medications.

28 TEST YOUR KNOWLEDGE Use the knowledge you have learned so far to build the following words. When you are finished, click the image to check your answers. Build a medical word that means: 1. Surgical repair of a vessel 2. Inflammation of (blood) vessels 3. Narrowing of the aorta 4. Tumor of fatty plaque 5. Enlargement of the heart 6. Recording of the electricity of the heart 7. Tumor of a blood vessel 8. Dilation of a vein 9. Destruction of a blood clot 10. Without a pulse Answer: 1. angi/o/plasty 2. vascul/itis 3. aort/o/stenosis 4. ather/oma 5. cardi/o/megaly 6. electro/cardi/o/gram 7. hemangi/oma 8. phleb/ectasis 9. thromb/o/lysis 10. a/sphyxia

29 PRONUNCIATION Practice pronouncing each term, then click the audio icon to hear it. Arrythmia (a-rith-me-a) Aorta (a-or-ta) Arteriosclerosis (ar-ter-ee-o-skler-o-sis) Arteriole (ar-te-re-ol) Asystole (a-sis-toe-lee) Bruit (bru-ee) Claudication (claw-di-kay-shun) An alteration in rhythm of the heartbeat either in time or force. The large arterial trunk that carries blood from the heart to be distributed by branch arteries through the body. Largest artery of the body. A chronic disease characterized by abnormal thickening and hardening of the arterial walls with resulting loss of elasticity. Any of the small terminal twigs of an artery that ends in capillaries. Cardiac arrest. Any of several generally abnormal sounds heard on auscultation. The quality or state of being lame. Audio and Definition Source: MedlinePlus Medical Dictionary, public domain.

30 Diastole (di-as-toe-lee) Endothelium (en-do-thee-lee-um) Fibrillation (fi-bri-lay-shun) Hemangioma (he-man-je-o-ma) Ischemia (is-ke-me-a) Necrosis (ne-kro-sis) Pericardium (per-i-kar-de-um) The passive rhythmical expansion or dilation of the cavities of the heart during which they fill with blood. A single layer of thin flattened cells that line internal body cavities. Very rapid irregular contractions of the muscle fibers of the heart resulting in a lack of synchronism between heartbeat and pulse. A usually benign tumor made up of blood vessels that typically occurs as a purplish or reddish slightly elevated area of skin. Deficient supply of blood to a body part (as the heart or brain) that is due to obstruction of the inflow of arterial blood (as by the narrowing of arteries by spasm or disease). Death of living tissue; specifically : death of a portion of tissue differentially affected by local injury (as loss of blood supply, corrosion, burning, or the local lesion of a disease). Protective covering of the heart. Audio and Definition Source: MedlinePlus Medical Dictionary, public domain.

31 Saphenous (sa-fee-nus) Spygmomanometer (SFIG-mo-ma-NOM-e-ter) Systole (SIS-toe-lee) Thrombocytosis (THROM-bo-si-TOE-sis) Valvulitis (val-vu-li-tis) Venule (VEN-yule or VEEN-yule) Of, relating to, associated with, or being either of the saphenous veins. An instrument for measuring blood pressure and especially arterial blood pressure. Of, relating to, associated with, or being either of the saphenous veins. Increase and especially abnormal increase in the number of blood platelets. A small vein; especially : any of the minute veins connecting the capillaries with the larger systemic veins. A small vein; especially : any of the minute veins connecting the capillaries with the larger systemic veins You have now completed chapter 5. To navigate back to the main Moodle page, click the back button in your browser. Audio and Definition Source: MedlinePlus Medical Dictionary, public domain.