BIOLOGY STUDY PACKET CARDIOVASCULAR SYSTEM SC.912.L AA

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1 BIOLOGY STUDY PACKET CARDIOVASCULAR SYSTEM SC.912.L AA Spring 201 The intent of this packet is to supplement regular classroom instruction, not to replace it. This also supposes that the students have access to their textbook material, both hard-copy and on-line.

2 Benchmark: SC.912.L AA Describe the factors affecting blood flow through the cardiovascular system. Benchmark clarification: Students will identify factors that affect blood flow and/or describe how these factors affect blood flow through the cardiovascular system. Content limit: Prior Knowledge: Items may address factors such as blood pressure, blood volume, resistance, disease and exercise. Students should know information from SC.6.L.14.5, which is to identify and investigate general functions of body systems and describe ways these systems interact with each other to maintain homeostasis. Text book references: Regular Biology, Holt by Stephen Nowicki, Chapter 30 Honors Biology, Pearson by Miller & Levine, Chapter 33.1 & 33.2 Vocabulary: Artery(ies), veins, capillary(ies), pacemakers, blood pressure (systolic and diastolic), myocardium, platelets, atherosclerosis, cholesterol, hypertension, stroke Background information: Arteries and Veins structural differences The structural differences between arteries and veins are all based in their relationship to the heart. You see, since arteries receive blood from the heart, the blood they receive is under a lot of pressure. Can you picture how much pressure the arteries near the heart (like the pulmonary trunk and the aorta) have to withstand every time the ventricles squirt out a load of blood? At the same time, this pressure helps the blood move through the arteries-- even when the arteries are running in opposition to gravity (like the common carotid artery running toward the head). The veins only receive the blood after it has travelled quite far from the heart. The blood pressure in the veins is thus much less; the blood is certainly much less likely to burst through walls of the veins than arteries. Also, because the blood pressure is small in the veins, it is not going to be enough to return all that blood to the heart; in fact, the blood could easily back up or collect in these vessels, right? Knowing these facts, you should be able to imagine the following needs of the two types of blood vessels: o Arteries: must be able to endure high pressure of blood o Veins: must be able to prevent blood from backing up Must be able to allow some blood to collect without bursting These are the very conditions that the different structures of arteries and veins reflect

3 Arteries have thick walls Arteries and arterioles have thicker walls than veins and venules, respectively. The increased amount of smooth muscle that is found in arteries gives them extra strength and elasticity to deal with the surges of blood from the heart Veins have valves and wider inner diameters Veins have valves within them to prevent backflow of blood. Blood is allowed to go toward the heart, but it cannot fall back the other way. These types of valves are especially important in getting blood back from places like your legs, all the way back to the heart. When a health professional draws blood from you, they draw blood from your veins. You may have known that already, but whether or not you knew that, now you should know why Veins, with their thinner walls and larger diameters are easier to stick with a needle and to extract blood from. 2. The thinner the vessel, the less the innervation, so the less painful to stick with a needle. 3. Veins have blood under less pressure within them, so when you stick a vein with a needle, blood will not typically seep out much through your injection site. 4. Veins "store" blood, so much more blood is readily available in your veins. Heart Disease Facts America's Heart Disease Burden In 2008, over 616,000 people died of heart disease. Heart disease caused almost 25% of deaths almost one in every four in the United States. 1 Heart disease is the leading cause of death for both men and women. More than half of the deaths due to heart disease in 2008 were in men. 1 Coronary heart disease is the most common type of heart disease. In 2008, 405,309 people died from coronary heart disease. 1 Every year about 785,000 Americans have a first heart attack. Another 470,000 who have already had one or more heart attacks have another attack. 2 In 2010, coronary heart disease alone was projected to cost the United States $108.9 billion. 3 This total includes the cost of health care services, medications, and lost productivity. Deaths Vary by Ethnicity Heart disease is the leading cause of death for people of most ethnicities in the United States, including African Americans, Hispanics, and whites. For American Indians or Alaska Natives and Asians or Pacific Islanders, heart disease is second only to cancer. Below is the percentage of all deaths caused by heart disease in 2008, listed by ethnicity. 1

4 Race of Ethnic Group African Americans 24.4 American Indians or Alaska Natives 17.9 Asians or Pacific Islanders 23.2 Hispanics 20.7 Whites 25.1 All 24.9 % of Deaths Risk Prevention For people with heart disease, studies have shown that lowering cholesterol and blood pressure levels can reduce the risk of o Dying from heart disease. o Having a nonfatal heart attack. o Needing heart bypass surgery or angioplasty. o For people without heart disease, lowering cholesterol and blood pressure levels can reduce the risk for developing heart disease. Early Action is Key In a 2005 survey, most respondents 92% recognized chest pain as a symptom of a heart attack. Only 27% were aware of all major symptoms and knew to call when someone was having a heart attack. 4 About 47% of sudden cardiac deaths occur outside a hospital. This suggests that many people with heart disease don't act on early warning signs. 5 Americans at Risk Below is the percentage of U.S. adults with heart disease risk factors in Risk Factor % Inactivity 53 Obesity 34 High Blood Pressure 32 Cigarette Smoking 21 High Cholesterol 15 Diabetes 11 In 2003, approximately 37% of adults reported having two or more of the risk factors listed above. 7 Source: Center for Disease Control and Prevention

5 Benefits of Exercise: Exercise for a Healthy Heart A sedentary (inactive) lifestyle is one of the top risk factors for heart disease. Fortunately, it's a risk factor that you can do something about. Regular exercise, especially aerobic exercise, has many benefits. It can: Strengthen your heart and cardiovascular system. Improve your circulation and help your body use oxygen better. Improve your heart failure symptoms. Increase energy levels so you can do more activities without becoming tired or short of breath. Increase endurance. Lower blood pressure. Improve muscle tone and strength. Improve balance and joint flexibility. Strengthen bones. Help reduce body fat and help you reach a healthy weight. Help reduce stress, tension, anxiety, and depression. Boost self-image and self-esteem. Improve sleep. Make you feel more relaxed and rested. Make you look fit and feel healthy. Regular exercise improves the heart because it is a muscle and just like all muscles if you exercise it regularly it becomes stronger, and a strong healthy heart is probably the single most important factor in preventing disease - In fact it can literally save your life and you can ask no more of any muscle than that. The reason exercise works to keep your heart healthy is because when you train your heart is required to work harder than normal and therefore pumps more oxygen filled blood throughout your body. This improves your circulation and helps to keep all of your organs and muscles healthy. The result is your heart becomes stronger and therefore less susceptible to disease which is a great benefit on its own but it gets even better than that because regular exercise will also lower your resting heart rate meaning that it doesn t have to work as hard to do its job and just like a machine the less it has to work the longer it will last. If that sounds great just consider for a moment that a very fit athlete can achieve a resting heart rate of beats per minute whilst a normal person of the same age will have a resting heart beat of beats per minute. As you can see the athlete s heart only has to do two thirds of the work of an average persons which helps maintain a healthy heart. The more research that is done the more scientists are realizing that the worst thing you can do to for a healthy heart is nothing at all because the fact is, a sedentary life style is a major cause of heart disease and heart attacks. So when it comes to your heart it is a classic case of use it or lose it and you only have to look at the statistics of America to confirm this.

6 The sedentary or inactive life style that has swept the country has led to heart attacks and coronary disease becoming the number one cause of death and disability in the United States but the sad thing is it doesn t have to happen if people would only get of their backsides and become more active. For instance, did you know that a good exercise program will reduce your chances of having a heart attack by as much as 45%? And you also have the other health benefits of exercise to take into consideration such as the reduced risk of developing diabetes, obesity, high blood pressure as well as preventing many other horrible diseases. Stroke Symptoms By Mayo Clinic staff Watch for these signs and symptoms if you think you or someone else may be having a stroke. Note when signs and symptoms begin, because the length of time they have been present may guide treatment decisions. Trouble with walking. You may stumble or experience sudden dizziness, loss of balance or loss of coordination. Trouble with speaking and understanding. You may experience confusion. You may slur your words or be unable to find the right words to explain what is happening to you (aphasia). Try to repeat a simple sentence. If you can't, you may be having a stroke. Paralysis or numbness on one side of your body or face. You may develop sudden numbness, weakness or paralysis on one side of your body. Try to raise both your arms over your head at the same time. If one arm begins to fall, you may be having a stroke. Similarly, one side of your mouth may droop when you try to smile. Trouble with seeing in one or both eyes. You may suddenly have blurred or blackened vision, or you may see double. Headache. A sudden, severe "bolt out of the blue" headache, which may be accompanied by vomiting, dizziness or altered consciousness, may indicate you're having a stroke.

7 Students complete the following: 1. Students Prepare a Heart Health Pamphlet such as you would find in your doctor s office summarizing the different aspects of heart disease and the benefits of exercise. Include pictures from the internet or magazines to help make your point. 2. This concept map can be accessed on Chapter 30, Section 1 Interactive Review

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9 4. FCAT Style Questions: 1. Many athletes who are in good condition have heartbeat rates that are substantially slower than the 60 to 80 beats per minute (bpm) considered normal for the rest of us. Former cyclist Lance Armstrong routinely had a resting heart rate of about 32 bpm. For a non-athlete, a heartbeat rate this low might be cause for hospitalization, but the rate of blood flow in an athlete's body is not affected by it. How can an athlete's body function normally with such a low heartbeat rate? A. People who are athletes are born with slow heart rates so it is normal for them. B. Exercise strengthens the athlete's heart muscle so more blood is pumped with each beat. C. An athlete's heart rate is higher than normal while exercising so it averages out to normal. D. More capillaries appear in muscle tissue with exercise so blood flow is more efficient. 2. In the human circulatory system, veins have valves but arteries do not. What would be the most likely result if veins did NOT have valves? A. Blood would return to the heart through the arteries. B. Blood would have higher pressure after passing through capillaries. C. Blood would have difficulty returning to the heart. D. Blood would not be able to leave the heart with any force. 3. Arteries not only carry blood away from the heart, they also help keep it moving forward. What feature of an artery's structure makes it particularly good at doing this? A. Their walls are made of layers of stretchy muscle tissue. B. They have walls made of rigid, inflexible muscle tissue. C. The small pumps in the arterial walls help move blood forward. D. The paddle-like valves in the arteries sweep the blood forward. 4. Which of the following would cause the brain to send signals which would cause capillaries in the calf muscles to dilate while at the same time closing off some of the capillaries in the digestive tract? A. eating dinner B. going running C. standing still D. lying down 5. After a man suffered a stroke, he was unable to use his left arm. What happened inside his body during the stroke that led to his losing the ability to use his left arm?

10 A. A blood clot blocked an artery leading into his left arm during the stroke. B. Aging capillaries in his left arm collapsed and shut down during the stroke. C. A surge of blood into his brain rearranged some neuron connections during the stroke. D. Blood flow to a portion of the right side of his brain was cut off during the stroke. 6. When a person has high blood pressure, the walls of their arteries remain stretched abnormally and become injured. Once an arterial wall is injured like this, what is likely to happen? A. Deposits of LDL cholesterol and white blood cells will collect at the site of injury resulting in atherosclerosis. B. The body will build a new piece of artery to replace the injured section and blood will be rerouted through it. C. Cholesterol will be deposited along the inside of the artery narrowing its diameter and lowering blood pressure. D. Blood will leak slowly out of the thinning walls of the artery and eventually lower the blood pressure. 7. Which of the following might cause the platelets in your blood to form clots? A. running a race B. sitting for a whole day C. eating leafy vegetables D. cutting your finger 8. A 20-year-old man decided to jump into a very cold lake. What is the MOST likely way in which his circulatory system will respond after he jumps into the water? A. Many of the capillaries in his extremities will shut down so more of his blood will stay in the warm core of his body. B. Capillary beds in his leg and arm muscles will get a rush of blood to encourage him to swim to shore more quickly. C. The shock of hitting the very cold water will cause a rush of adrenaline which will make his heart stop beating. D. He will have difficulty breathing at first but once his lungs warm up he will be able to breathe more easily.