The function of the heart is to maintain a constant circulation of blood around the body by its constant pumping action. The walls of the heart are composed of cardiac muscle which never tires and has its own inherent rhythm which can be modified by nerve impulses. The heart is divided into four chambers; the two on the right side are completely separated from the two on the left by the septum. The right side of the heart contains deoxygenated blood, the left contains oxygenated blood. Heat Beat During one cardiac cycle or heart beat: •Atria and ventricles relax together (diastole), atria fill with blood: 0. 4 seconds.
•Atria contract (atrial systole), blood is forced into arteries: 0. 1 seconds •Ventricles contract (ventricular systole), blood is forced into arteries: 0. 3 seconds. Total beat = 0. 8 seconds. 75 beats per minute. The rate of heart beat increases with exercise so that more blood is pumped to the lungs to be oxygenated, and to the muscles to provide extra oxygen for increased respiration and energy production. Causes and Effects of Heart Attacks Animal fats such as cholesterol are believed to be the main cause of atherosclerosis. The fat is laid down on the walls of the arteries and reduces their internal diameter.
This causes the high blood pressure in hypertension. Hypertension is dangerous because it shows blockage or reduced blood flow in blood vessels. Such blockage (thrombosis) in reducing the oxygen supply to the brain can cause unconsciousness and death. When this blockage occurs in the coronary artery, which supplies the heart muscle, a coronary heart attack is caused. This blockage reduces the supply of oxygen to the muscle, stopping it from contracting. Sudden death results from a main blockage and this is responsible for more than one – third of all deaths in affluent countries such as the USA.
A similar blockage in arteries to the brain causes death by cerebral hemorrhage. Arteriosclerosis, an associated disease, occurs when the walls of the arteries harden and become less elastic. This also increases blood pressure and so hypertension. The nicotine in cigarette smoke also causes arteriosclerosis and coronary thrombosis. Here’s a quick look at the rising heart attack rate among middle-aged U. S. women. That trend, reported in 2009, is based on more than 8,000 U. S. men and women aged 35-54 studied between 1988-1994 and 1999-2004. During both time periods, heart attacks were more common among men than women.
But men’s heart attack rate dropped from 2. 5% to 2. 2%, while women’s heart attack rate rose from 0. 7% to 1%. In short, heart attack rates headed down for men, and up for women. Why? Men had a few things going for them. Their blood pressure dropped, their HDL (“good”) cholesterol improved, and they were less likely than women to smoke. “The lower rates of smoking, improved blood pressure levels, and improved HDL among men suggest that educational campaigns aimed at men are working,” says researcher Amytis Towfighi, MD, of the University of Southern California.
But women showed only one positive trend: an improvement in their HDL cholesterol level. They also had two major drawbacks: a higher rate of smoking and an uptick in diabetes, most likely because of obesity. Heart Attack Hazard: ObesityAbout 35% of U. S. women are obese, according to the CDC. And those extra pounds pack a cardiovascular threat. “We used to think obesity was a risk factor simply because it is associated with established risk factors such as high blood pressure and diabetes and high cholesterol levels.
But now we recognize that by itself, it increases risk,” says Martha L. Daviglus, MD, PhD, professor of preventive medicine and medicine at Northwestern University’s Feinberg School of Medicine in Chicago and spokeswoman for the American Heart Association. Cardiovascular disease is a class of diseases that involves the heart, the blood vessels (arteries, capillaries and veins) or both. Cardiovascular disease is the #1 Killer of women, but as women, but as a woman, even if you know that you’re probably too busy most days to think about it. But you should think about it because what you do each day in part determines you risk for developing cardiovascular disease and suffering its life – threatening consequences.
“Cardiovascular disease” develops over – time, affecting your body in ways you might not notice until it’s too late. By thinking about it now, you can learn ways to reduce your risks recognize the warning signs of a heart attack and advocate getting the help you need. One in three women over the age of 20 has some form of cardiovascular disease. It strikes women at younger ages than most people think and the risk rises in idle age. According to the Centers for Disease Control and Prevention, heart disease is the third most common cause of death among women ages 25 to 44 years old and two thirds of women who have heart attack never fully recover.
More women have strokes than men. According to the American Stroke Association; each year more than a 100, 000 women under the age of 65 in the United States will have stroke. Smoking is a major risk factor for heart attack in women. Roughly one third of the adults in the United States have high blood pressure. According to the National Heart, lung and blood Institute. After age 55, women are at increased risk of hypertensions, a major contributor to cardiovascular disease. REFERENCE PAGE 1 ONE AUTHOR PAGE 2 ONE AUTHOR P. GADD1973, 1978, 1984, 1993 DESIGN AND ILLUSTRATION.