ANATOMY AND PHYSIOLOGY OF THE HEART. HEART DISEASES
The heart (to be) _____ a pear shaped, muscular organ. It (to be) _____responsible for pumping blood through the blood vessels by repeated, rhythmic contractions. The heart (to compose) ______________ of cardiac muscle. It (to be) _____an involuntary muscle tissue.. In the human body, the heart (to situate) ______normally ________________ to the left of the middle of the thorax. The left lung (to be) _____smaller than the right lung because the heart (to occupy) ____________ more of the left hemithorax. The heart (to enclose) ____________by a sac known as the pericardium and (to surround) ___________________by the lungs. In normal adults, the mass of the heart (to be) ______ 250-350 g (9-12 oz), or about three fourths the size of a clenched fist, but extremely diseased hearts can (to be) ______ up to 1000 g in mass due to hypertrophy. It (to consist) ____________of four chambers, the two upper atria and the two lower ventricles. The function of the right side of the heart (to be) ________ to collect deoxygenated blood, in the right atrium, from the body and pump it, via the right ventricle, into the lungs (pulmonary circulation) so that carbon dioxide can (to drop) _________ off and oxygen (to pick) __________ up (gas exchange). The left side (to collect) ___________ oxygenated blood from the lungs into the left atrium. From the left atrium the blood (to move) ______________ to the left ventricle which (to pump) _________ it out to the body. On both sides, the lower ventricles (to be) _______ thicker and stronger than the upper atria. The muscle wall surrounding the left ventricle (to be) ______ thicker than the wall surrounding the right ventricle due to the higher force needed to pump the blood through the systemic circulation. The heart (to beat) ___________ up to 120 times per minute in childhood. When resting, the adult human heart (to beat) ______________at about 70 bpm (males) and 75 bpm (females), but this rate (to vary) __________ among people. However, the reference range (to be) ______ normally between 60 bpm (if less it (to term) ____________ bradycardia) and 100 bpm (if greater, it (to term) __________ tachycardia). The infant/neonatal rate of heartbeat (to be) _______ around 130-150 bpm, the toddler's about 100–130 bpm, the older child's about 90–110 bpm, and the adolescent's about 80–100 bpm. The pulse (to be) ______ the most straightforward (simple) way of measuring the heart rate. Auscultation is also a method of heart rate measurement. The study of diseases of the heart (to know) _____________ as cardiology. Important diseases of the heart include:
Congenital heart defects. Acute myocardial infarction (AMI or MI), (to know) _____commonly ___________ as a heart attack. MI (to be) ______a disease state that (to occur) ____________ when the blood supply to a part of the heart (to interrupt) ________________. MI (to be) _____ a medical emergency, and the leading cause of death for both men and women all over the world. Important risk factors (to be) _____ a previous history of vascular disease such as atherosclerotic coronary heart disease and/or angina, a previous heart attack or stroke, any previous episodes of abnormal heart rhythms, older age- especially men over 40 and women over 50, smoking, excessive alcohol consumption, the abuse of certain drugs, high triglyceride levels, high LDL ("bad cholesterol") and low HDL ("good cholesterol"), diabetes, high blood pressure, obesity, and chronically high levels of stress in certain persons. Classical symptoms of acute myocardial infarction (to include) ___________ chest pain, shortness of breath, nausea, vomiting, palpitations, sweating, and anxiety. Patients frequently (to feel) _____________ suddenly ill. Women often experience different symptoms than men. The most common symptoms of MI in women (to include) ____________ shortness of breath, weakness, and fatigue. Approximately one third of all myocardial infarctions (to be) _________ silent, without chest pain or other symptoms. Immediate treatment for suspected acute myocardial infarction (to include) ______ oxygen, aspirin, glyceryl trinitrate and pain relief. The patient (to receive) ________________ a number of diagnostic tests, such as an electrocardiogram (ECG, EKG), a chest X-ray and blood tests. Further treatment may (to include) _____________ either medications to break down blood clots that (to block) ____________ the blood flow to the heart, or mechanically restoring the flow by dilatation or bypass surgery of the blocked coronary artery. Coronary care unit admission (to allow) ________________ rapid and safe treatment of complications such as abnormal heart rhythms. Myocardial infarction 9to be) ______ a common presentation of ischemic heart disease. The WHO estimated that in 2002, 12.6% of deaths worldwide (to be) _______ from ischemic heart disease. Ischemic heart disease (to be) _____ the leading cause of death in developed countries, but third to AIDS and lower respiratory infections in developing countries. In the United States, diseases of the heart (to be) _______ the leading cause of death, causing a higher mortality than cancer (malignant neoplasms). Coronary heart disease (to be) _____ responsible for 1 in 5 deaths in the U.S.. Some 7,200,000 men and 6,000,000 women (to live) _______________________ with some form of coronary heart disease. 1,200,000 people (to suffer) __________ a (new or recurrent) coronary attack every year, and about 40% of them (to die) __________ as a result of the attack. This means that roughly every 65 seconds, an American (to die) _________ of a coronary event. Risk factors for atherosclerosis are generally risk factors for myocardial infarction: older age male gender cigarette smoking hypercholesterolemia (especially high low density lipoprotein and low high density lipoprotein) diabetes (with or without insulin resistance) high blood pressure obesity Many of these risk factors (to be) _______ modifiable, so many heart attacks can (to prevent) __________________by maintaining a healthier lifestyle. Physical activity, for example, (to associate) ________________________ with a lower risk profile. Non-modifiable risk factors (to include) ________________ age, gender, and family history of an early heart attack (before the age of 60), which (to think) _________________________ of as reflecting a genetic predisposition. Socioeconomic factors such as a shorter education and lower income (particularly in women), and living with a partner may also (to contribute) _________________ to the risk of MI. Women who (to use) _____________ combined oral contraceptive pills (to have) ______________ a modestly increased risk of myocardial infarction, especially in the presence of other risk factors, such as smoking. Inflammation (to know) _________________ to be an important step in the process of atherosclerotic plaque formation. The general appearance of patients may (to vary) ___________ according to the experienced symptoms; the patient may (to be) _______ comfortable, or restless and in severe distress with an increased respiratory rate. A cool and pale skin (to be) ______common and (to point) ___________ to vasoconstriction. Some patients (to have) ___________ low-grade fever (38–39 °C). Blood pressure may (to be) _______ elevated or decreased, and the pulse can (to be) _______ irregular. The primary purpose of the electrocardiogram (to be) _____ to detect ischemia.
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