HSC4711 Exam 2 Study Guide Cardiovascular Disease CVD heart disease o 80 million Americans o leading cause of death in US o one life every 37 seconds o killed more than 650 000 Americans in 2005 Cardiovascular system o consists of heart and blood vessels together working to move blood through body o heart four chambered fist sized muscle pumps deoxygenated blood to lungs and delivers oxygenated blood to body right pumps to lungs in pulmonary circulation left pumps to body in systemic circulation flow deoxygenated blood flows from vena cavae into right atrium which pumps blood to the right ventricle which pumps blood through pulmonary artery into lungs blood flows from lungs into left atrium which pumps into left ventricle which pumps blood into aorta to the rest of the body vena cava either of two large veins through which blood is returned to right atrium of heart atria two upper chambers which collect blood before passing to ventricles ventricles two lower chambers that pump blood through arteries to lungs and other parts of body aorta large artery that receives blood from left ventricle and distributes to rest of body body s largest artery 150 lb person has about 5 quarts of blood which circulates about once per minute o systole contraction of heart o diastole relaxation of heart o veins carry blood to heart thin walls o arteries carry blood away from heart thick elastic walls that allow expanding and relaxation with volume of blood being pumped o venules blood empties from capillaries into venules which connect to veins that return blood back to heart and tissues one cell thick o capillaries smallest arteries branch into these exchange oxygen and nutrients between blood o coronary arteries system of arteries branching from aorta that provides blood to heart muscle blockage of these is leading cause of heart attack o collateral circulation extra pathways to use extra blood o ischemia lack of oxygen due to poor blood flow Major risk factors for CVD that can be changed o TOBACCO USE one in five deaths is attributable to smoking smokers are 2 3x more likely to die from heart attack than nonsmokers cigarette smoking doubles risk of stroke damages lining of arteries reduces level of HDLs good cholesterol and raises bad cholesterol nicotine increases BP and heart rate CO displaces O2 in blood reducing the oxygen available to body causes platelets cell fragments in blood necessary for formation of blood clots to stick together leading to clotting as well as speeding development of fatty deposits in arteries ETS environmental tobacco smoke increases your risk of death from coronary heart disease up to 30 35000 people die form CVD each year from ETS o HIGH BLOOD PRESSURE hypertension sustained abnormally high blood pressure risk factor for heart attack and stroke and is considered a form of CVD itself created by pumping action of heart affected by many things exercise excitement etc short periods of high BP are normal but chronic high BP is a health risk expressed as two numbers first number is systolic second is diastolic results from increased output of blood by heart OR from increased resistance to blood flow in arteries increased resistance to blood flow can be caused by constriction of smooth muscle surrounding arteries of by atherosclerosis form of CVD in which inner layers of artery walls made thick and irregular by plaque deposits arteries become narrow and blood supply is reduced scars and hardens arteries which makes them less elastic and further increases blood pressure causes heart to work harder than normal which strains both the heart and arteries often called silent killer because it has no symptoms 33 of adults have hypertension 140 159 90 99 stage 1 160 100 stage 2 37 of adults have prehypertension 120 139 80 89 incidence of hypertension increases with age highest rate in African American 41 who get disease more severe more resistant to treatment more likely to be fatal at early age get BP check every two years DASH diet recommended for people with hypertension emphasizes more fruits veggies whole grains and increasing fiber and potassium death rates from CVD begin to rise when BP is 115 70 prehypertension o HIGH CHOLESTEROL fatty wax like substance that circulates in blood and is important for cell membranes sex hormones vitamin D fluid coating lungs and protective nerve sheaths essential for proper functioning of body excess can clog arteries and cause CVD lipoproteins protein and lipid substances in blood that carry fats and cholesterol classified according to density size chemical composition LDLs low density lipoprotein lipoprotein containing moderate amount of protein and high amount of cholesterol bad cholesterol excess cholesterol deposited in blood vessels increases CVD risk blocked coronary artery heart attack artery supplying brain blocked stroke HDLs high density lipoproteins helps transport cholesterol out of artery protects against CVD good cholesterol shuttle unused cholesterol back to liver for recycling test lipoprotein levels every 5 years beginning at age 20 high LDL high cholesterol high triglyceride levels combined with low HDL levels are associated with higher CVD risk good HDL levels seems to offer protection from CVD even when total cholesterol is high increase fiber more saturated fats less unsaturated fats and trans fats exercise regularly eat more fish fruit veggies whole grains o PHYSICAL INACTIVITY 40 60 million Americans are so sedentary they are at high risk for CVD magic bullet against CVD decreases BP decreases resting heart rate increases HDL levels maintains weight improves condition of blood vessels controls prevents diabetes o OBESITY risk of CVD is 2 3x more likely in obese people BMI 30 for every 5 unit increase in BMI risk goes up by 30 associated strongly with hypertension high cholesterol insulin resistance diabetes physical inactivity increasing age heart has to work harder can lead to ventricular hypertrophy enlargement in heart cause by elevated pressures in heart chambers which causes heart muscle to die eventually even a modest weight reduction 5 10 of body weight can reduce CVD risk for obese people o DIABETES elevated blood glucose levels due to an insufficient supply inadequate action of insulin doubles risk of CVD for men and triples for women loss of 5 10 years off life damage endothelial cells that line arteries making them more vulnerable to atherosclerosis often have platelet and blood coagulation blood clotting