The Heart http://www.news-medical.net/health/What-is-Cardiovascular-Disease.aspx
The human heart is the size of a fist. However, it works relentlessly from before birth to death. The heart begins beating by 21 to 28 days after conception and beats throughout life. It is also the strongest muscle in the human body.
The average heart beats about 100,000 times daily or about two and a half billion times over a seventy year lifetime. With each beat, the heart pumps blood through the blood vessels or arteries to all parts of the body. It beats approximately 70 to 80 times a minute. This rate can double during exercise or at times of emotion.
The cardiovascular system Blood cells, called erythrocytes, carrying oxygen attached to their hemoglobin protein, travel from the left ventricle into the Aorta, the major artery leaving the heart. It travels via arteries of ever-decreasing size till it reaches the narrowest of arteries called capillaries (the progression is arteries -> arterioles -> capillaries). It is in the capillaries where the oxygen is passed from erythorcytes to the organs and tissues of the body. It is also in the capillaries where the erythrocytes pick up carbon dioxide (CO2) to return to the lungs.
Having delivered its oxygen and nutrients and having collected waste products, blood is brought back through a system of progressively enlarging veins (the progression is venules -> veins) to the heart where oxygen poor blood enters into the right atrium from the inferior (low extremities) and superior (upper extremities) vena cava. From the right atrium, this oxygen poor blood passes into the right ventricle where it is then pumped to the lungs through the pulmonary artery. In the lungs, carbon dioxide dissolves out of the blood and oxygen dissolves in. The oxygenated blood is then returned to the right atrium through the pulmonary vein. (The pulmonary circuit is the only instance where deoxygenate blood travels in an artery and oxygenated blood travels in a vein.) From the right atrium, this oxygenated blood is then passed to the right ventricle to begin the cycle anew.
This is called the circulatory system or the cardiovascular system and is vital for living. Cardiovascular system literally means “cardio” or heart and “vascular” or a system or network of blood vessels.
How many people do cardiovascular diseases affect? Diseases or disorders of this system are termed cardiovascular diseases. Cardiovascular diseases kill an estimated 17 million people worldwide each year. Majority of these are due to heart attacks and strokes. Tobacco consumption and smoking remains the largest risk factor for cardiovascular diseases worldwide. It raises the risk of strokes as well.
Some of the cardiovascular diseases include: Coronary heart disease This is due to disease or narrowing of the blood vessels supplying the heart muscle. These blood vessels are called coronary blood vessels. Atherosclerosis is the most common cause and is caused due to hardening and narrowing of coronary arteries of heart by formation of plaques and plugs.
Coronary heart disease can be caused due to risk factors like high blood pressure, high blood cholesterol, tobacco use, obesity, unhealthy diet, physical inactivity, diabetes, advancing age, inherited disposition.
Congenital heart disease This is due to malformation or abnormal formations of the structures of the heart at birth. This may be inherited or due to other factors. This includes holes in the heart, abnormal valves, abnormal heart chambers etc. Mothers taking drugs, alcohol, mothers with infections like rubella or mothers with poor diets deficient of vital nutrients are at risk of giving birth to babies with congenital heart defects.
Stroke or Cerebrovascular accident (CVA) This is caused when the blood supply to part of the brain is hampered. This may result from either blockage or rupture of a blood vessel in the brain. Those at risk include those with high blood pressure, heart rhythm disorders, high blood cholesterol, tobacco use, diabetes and advancing age.
Congestive heart failure This is caused when the heart muscles become progressively unable to pump blood into the blood vessels. The heart becomes congested with fluid. Those at risk include those with high blood pressure, heart rhythm disorders, heart attacks, obesity etc.
Peripheral arterial disease or peripheral vascular diseases This affects the arteries supplying the arms and legs. The risks are similar as those for coronary heart disease.
Deep venous thrombosis (DVT) and pulmonary embolism In DVT, blood clots form in the leg veins giving rise to severe pain and disability. These clots can dislodge and move to the heart and lungs leading to life threatening complications. Risk factors include long surgery, trauma, obesity, cancers, recent childbirth, use of oral contraceptive and hormone replacement therapy etc.
Rheumatic heart disease This is caused due to damage to the heart muscle and heart valves from rheumatic fever. This is caused due to infection with streptococcal bacteria.
Other cardiovascular diseases This includes tumors of the heart, blood vessel tumors or ballooning (aneurysm) of the blood vessels of the brain, cardiomyopathy, heart valve diseases, disorders of the lining of the heart or pericarditis, aortic aneurysm etc.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab) 1230L Heart Disease Health Center WedMD: Risk Factors for Heart Disease http://www.webmd.com/heart-disease/risk-factors-heart-disease
Some risk factors for heart disease you can control and some you cannot. Coronary artery disease causes roughly 1.2 million heart attacks each year, and more than forty percent of those suffering from a heart attack will die. Even more worrisome, 335,000 people with heart attacks will die in an emergency department or before ever reaching the hospital. According to the American Heart Association, over 7 million Americans have suffered a heart attack in their lifetime.
What Are the Risk Factors for Heart Disease? There are several risk factors for heart disease; some are controllable, others are not. Uncontrollable risk factors include: Male sex Older age Family history of heart disease Post-menopausal Race (African Americans, American Indians, and Mexican Americans are more likely to have heart disease than Caucasians)
Still, there are many heart disease risk factors that can be controlled. By making changes in your lifestyle, you can actually reduce your risk for heart disease. Controllable risk factors include: Smoking. High LDL, or "bad" cholesterol and low HDL, or "good" cholesterol. Uncontrolled hypertension (high blood pressure). Physical inactivity. Obesity (more than 20% over one's ideal body weight). Uncontrolled diabetes. High C-reactive protein which signals inflammation. Uncontrolled stress and anger.
What Can I Do to Lower My Risk of Heart Disease? Making changes in your lifestyle is a proven method for reducing your risk of heart disease. While there are no guarantees that a heart-healthy lifestyle will keep heart disease away, these changes will certainly improve your health in other ways, such as improving your physical and emotional well-being. Also, because some risk factors are related to others, making changes in one area can benefit other areas. Here are some ways you can reduce your risk of heart disease.
Quit smoking. Smokers have more than twice the risk for heart attack as nonsmokers. Smoking is also the most preventable risk factor. If you smoke, quit. Better yet, never start smoking at all. Nonsmokers who are exposed to constant smoke (such as living with a spouse who smokes) also have an increased risk. So taking measures to eliminate this exposure to smoke is important.
Improve cholesterol levels. The risk for heart disease increases as your total amount of cholesterol increases. In general, your total cholesterol goal should be less than 200 mg/dl; HDL, the good cholesterol, higher than 40 mg/dl in men and 50 mg/dl in women (and the higher the better); and LDL should be less than 130 mg/dl in healthy adults. For those with diabetes or multiple risk factors for heart disease, LDL goal should be less than 100 mg/dl (some experts recommend less than 70 mg/dl if you are very high risk). Interpretation and treatment of cholesterol values must be individualized, taking into account all of your risk factors for heart disease. A diet low in cholesterol and saturated and trans fat will help lower cholesterol levels and reduce your risk for heart disease. Regular exercise will also help lower "bad" cholesterol and raise "good" cholesterol. Medications are often needed to reach cholesterol goals.
Control high blood pressure. About 60 million people in the U.S. have hypertension, or high blood pressure, making it the most common heart disease risk factor. Nearly one in three adults has systolic blood pressure (the upper number) over 140, and/or diastolic blood pressure (the lower number) over 90, which is the definition of hypertension. Like cholesterol, blood pressure interpretation and treatment should be individualized, taking into account your entire risk profile. Control blood pressure through diet, exercise, weight management, and if needed, medications.
Control diabetes. If not properly controlled, diabetes can contribute to significant heart damage, including heart attacks and death. Control diabetes through a healthy diet, exercise, maintaining a healthy weight, and taking medications as prescribed by your doctor.
Get active. Many of us lead sedentary lives, exercising infrequently or not at all. People who don't exercise have higher rates of death and heart disease compared to people who perform even mild to moderate amounts of physical activity. Even leisure-time activities like gardening or walking can lower your risk of heart disease. Most people should exercise 30 minutes a day, at moderate intensity, on most days. More vigorous activities are associated with more benefits. Exercise should be aerobic, involving the large muscle groups. Aerobic activities include brisk walking, cycling, swimming, jumping rope, and jogging. If walking is your exercise of choice, use the pedometer goal of 10,000 steps a day. Consult your doctor before starting any exercise program.
Eat right. Eat a heart-healthy diet low in salt, saturated fat, trans fat, cholesterol, and refined sugars. Try to increase your intake of foods rich in vitamins and other nutrients, especially antioxidants, which have been proven to lower your risk for heart disease. Also eat plant-based foods such as fruits and vegetables, nuts, and whole grains.
Achieve and maintain a healthy weight. Excess weight puts significant strain on your heart and worsens several other heart disease risk factors such as diabetes, high blood pressure, and high cholesterol and triglycerides. Research is showing that obesity itself increases heart disease risk. By eating right and exercising, you can lose weight and reduce your risk of heart disease.
Manage stress. Poorly controlled stress and anger can lead to heart attacks and strokes. Use stress and anger management techniques to lower your risk. Learn to manage stress by practicing relaxation techniques, learning how to manage your time, setting realistic goals, and trying some new techniques such as guided imagery, massage, Tai Chi, or yoga.
Lexile 1050 CIS Unit
The Cardiovascular System (9th and 10th grade Biology)
SC.912.L.14.36 Describe the factors affecting blood flow through the cardiovascular system.
HE.912.C.1.4: Analyze how heredity and family history can impact personal health.
Essential Questions: o What are the structures and functions of the cardiovascular system?
o How does blood flow through the cardiovascular system?
o What biologic and lifestyle factors affect blood flow through the cardiovascular system? CIS Lesson The Cardiovascular System
1. Hook Engage: The Circulatory Song http://www.youtube.com/watch?v=q0s-1MC1hcE
2. Question #1 Write a few sentences describing what you know about how the heart pumps blood throughout the body.
3. Distribute article.
4. Pre-teach vocabulary: None
5. Text-marking: P = Physiological Process SF = Statistic or Fact related to the heart or CVS
6. Question #2 In a paragraph, describe the flow of blood through the heart. Begin with the deoxygenated, carbon dioxide rich blood, entering the heart.
7. Note-taking: What factors, both positive and negative, affect the risk of cardiovascular disease.
8. Task #3 You are a blood cell. Create a cartoon that depicts your journey through the entire body beginning with the reception of your very own oxygen molecule in the lungs and ending with
the surrender of your CO2 molecule in the lungs. Think back to cellular respiration to explain
where your oxygen molecule went to and where your CO2 molecule came from. Throughout your journey, be sure to introduce things from your readings that both block and facilitate your transport throughout the system.
Directed Note-Taking The Cardiovascular System Directions: Record notes containing the most important information relevant to the guiding question.
Page/ Paragraph# Notes Risk Benefit
Collaborative Work: After completing your chart, be prepared to compare your notes with others. Page/ Risk Benefit Paragraph# Notes Question Generator
Directions: Carefully review the text for words, phrases or statements that create questions in your mind. Discuss these questions in your group, and then document your group’s questions below.
Page/ Risk Benefit Paragraph# Notes
Collaborative Work: After completing your chart, be prepared to compare your notes with others. Directions: Write your ideas below in preparation for your final project. Use the information you learned in this unit and throughout the school year. You may also use research from additional outside sources. Be sure to cite those sources!