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The Heart.

Background

Try clenching your fist and then relaxing it. You have just imitated the beating of your heart. The heart is a living pump made of muscle. Each and every day, it beats over 100,000 times, pushing approximately 6 liters of blood through the nearly 90,000 miles (150,000 km) of blood vessels found in the body of an average adult. During its one minute round trip around your body, your blood carries with it essential nutrients, oxygen, and important chemical messengers (like hormones) to all the cells of your body. Your blood also carries away waste products from your cells, removes toxins like alcohol and drugs, and helps to eliminate invaders like bacteria and germs.

Your cardiovascular system is made up of your heart ("cardio") and blood vessels ("vascular"). The heart itself is a 4-chambered organ made of a special kind of smooth muscle tissue that can work continuously with very little rest. Your blood vessels are a network of elastic tubes that carry blood to and from the heart and lungs and throughout your body. These vessels include the arteries, arterioles, veins, and capillaries. Arteries, arterioles, and capillaries carry blood to the cells of your body. Other capillaries, and your veins, return the blood to the heart and lungs and pick up fresh oxygen and nutrients.

Heart History

Writings from ancient Greece, dating back 4,000 years, show that the early Greeks believed that the soul was carried through the blood. The Egyptians maintained that the blood stream originated from the heart, which was considered to be the center of all thought and feeling. Chinese doctors living 3,000 years ago wrote that the heart controlled the flow of blood and that the blood vessels carried air as well as blood. It was not until the early 17th century that a British doctor named William Harvey actually discovered how our cardiovascular system works by experimenting on living animals and dead human subjects. He described the heart as a pump that keeps blood moving in a one way path as it travels throughout our bodies.

Your Heart

The heart is located in the center of your chest behind your breast bone (the sternum) and is tilted slightly up and to the left. Your heart is about the size of your fist and contains four hollow sections called chambers which are separated by a membrane called the septum. (You also have a septum dividing the two sides of your nose.) At the openings of the chambers are special one-way doors called valves which ensure that the blood moves through your heart in the proper direction. The "lub-dub" sound you hear when your heart beats is actually the sound of these valves snapping open and closed as blood moves from one chamber to another.

Did you know it is easier to hear your heart beat on the left side of your chest? This is because the left side of your heart is stronger. The left side (which is reversed in this picture, because it is facing you, and shown on the right) must push blood through nearly 90,000 miles of blood vessels! The top left chamber of your heart (the atrium) receives oxygenated blood from your lungs. The lower left chamber (the ventricle) pumps blood out through the aorta and into the body.

The quieter right side of your heart (on the left in this illustrated view) orchestrates the movement of blood to the lungs and back. This is sometimes called the pulmonary (lung) circulatory system. The atrium on this side receives deoxygenated blood from your body. The ventricle then sends it to the lungs to pick up new oxygen supplies and returns it to the left side.

Heart Disease

Heart disease kills more Americans than any other cause - about 32 percent of all deaths in the U.S. each year. Of these, nearly three-fourths involve problems with hardening of the arteries. Nearly 60 million Americans (about one-quarter of our population) have some form of cardiovascular disease.

Tragically, atherosclerosis, a gradually progressive disease in which the blood vessels leading to and from the heart become clogged with deposits of a fatty substance called cholesterol, usually begins in childhood. (Cholesterol is found primarily in animal fats and meats.) Usually as atherosclerosis develops, your blood pressure (the amount of force your heart must exert to push your blood through your blood vessels) rises. As the blood vessel passages narrow, the heart must work harder putting strain on the vessels. Eventually the heart muscle is starved of the blood it needs to continue pumping, and the end result is a heart attack.

Heart Attack Symptoms

It is important to be able to recognize the signs of a heart attack when it happens, so that treatment can begin immediately. Quick treatment often means the difference between life and death. If someone you know experiences breathlessness, dizziness, or faintness, turns pale and clammy, or feels shooting or crushing pains in the chest or down the left arm, call for emergency medical assistance immediately.

Repairing Damaged Hearts

Many people with severely damaged hearts have heart surgery to replace faulty valves or may even receive a new heart. (The first successful heart transplant was performed in 1967 by Dr. Christiaan Barnard. The patient lived less than two weeks.) Today, heart transplantation is a common procedure and patients live for many years. Surgeries to implant artificial hearts and battery-operated heart pumps are also performed. Many heart patients, especially elderly ones, use implanted devices called pacemakers that send out electrical signals to keep the heart's rhythm regulated.

Preventing Heart Disease

While heredity plays an important rote in the development of heart disease, there are many things we can do to help prevent it. One of the most important things to do is to learn to make heart-healthy choices, like eating a healthy diet of fruits, grains, vegetables, and other foods; getting enough exercise; and living a tobacco-free life. Besides the obvious health benefits, our country could save over $2,500 a year per person in heart health care alone. That's more than $151 billion annually. It is also important to realize that men and women are now equally likely to suffer from heart disease and heart attacks, especially after age 50.

Surprisingly, recent studies show that brushing your teeth can help keep your heart stronger. Scientists have found that the bacteria which form plaque on your teeth, can contribute to heart disease when they mix with your blood. This bacteria can cause damage to your blood vessels. Brushing and flossing your teeth and regular cleanings at the dentist can actually help prevent heart disease.

Prevention and awareness are our main weapons against cardiovascular illness and heart attack. Education programs in schools and by the American Heart Association are helping to educate children about how to take care of their hearts. Healthy habits begin at an early age and continue for a lifetime.

Level Pre-A

Main Concepts: The heart pumps blood throughout our whole body. Exercise helps Keep our hearts healthy.

Picture Activity

Ask what the 2 pictures are next to WHY-FLY. They are both pictures of hearts. Ask if they look just alike. Our real hearts don't look that much like Valentine hearts. Point out that WHY-FLY has his hand in the center of his chest. This is where our hearts are located (actually a little to the left of center). Now, have them make a fist and squeeze and relax it a few times. Explain that their hearts are about the same size and shape as their fists. Tell them that this squeezing is just like the way their hearts beat. Explain that the heart is really a super strong muscle that pumps blood throughout their whole bodies.

Vocabulary

First go over all the pictures together - hat, hand, heart, hair. Then have them write the letter "h" in each heart and follow the dotted paths that match each word with its picture.

Weekly Lab

You need: toilet paper (or paper towel) tubes, 5 oz. paper kitchen cups, clock with a second-hand. Try to obtain a real stethoscope from your school nurse or other health professional, so your students can have an opportunity to hear their own hearts through this instrument. A word of caution: Real stethoscopes are very sensitive. Your students should be careful not to speak loudly into them or place them near a loud noise source. In this lab, they will be making their own versions of stethoscopes using a toilet paper (or paper towel) tube alone or with 5 oz. paper kitchen cup taped to one end. (The 5 oz. cup fits perfectly over these tubes. Just tear or cut out the bottom of the cup.) Have them compare listening from both ends of their "stethoscope." Did they hear better when it was facing one way or another? Have them also try putting cups on both ends. Another option is to use a turkey baster with the bulb removed or a kitchen funnel. (Remind them to be very careful and to gently place their ears near these objects when listening!) Be sure the room is very quiet and have them listen for their partner's heartbeats in the middle of their chests, a little to the left of center. They may need to move their "stethoscopes" around a bit to find the best place to hear. As an extension, when they find their partner's heartbeat, time them for one minute (or less), and have them count all the beats they hear. (Their hearts beat at about 90 beats a minute.)

Weekly Problem

Tell your students that this is a picture of the inside of their hearts. Inside are spaces like little rooms. They are called chambers. Ask them count the rooms (chambers) they see inside the heart. (Our hearts have 4 hollow chambers.) Explain that our hearts pump blood around and around our bodies. The heart muscle itself is a deep purplish brown color. One side of our heart has blood that has come from our lungs and is full of fresh air and oxygen. The heart will send this blood out to our whole bodies. Blood filled with oxygen looks red. The other side of the heart pumps in blood that has already traveled around our bodies and has dropped off its oxygen supply. The heart will pump this blood back to the lungs to get more fresh air (oxygen). This blood is darker, because there is less oxygen in it. It looks bluish in color. Have them count and color in the dots on the left first. Then have them color in the corresponding areas on the heart. In addition, see if they can find a blue vein in their wrists or in the crook of their elbows.

Storytelling

Ask if they have ever noticed that their hearts beat differently at different times. Sometimes they may beat faster. Discuss the pictures. Can they think of some situations when their hearts beat faster? Have them draw pictures to accompany their stories.

Challenge

Try to get enough tennis balls so your students can work in groups of 2 or 3. Have them try to flatten the ball with their hands. Tell them that their hearts are much stronger than their hands. In fact, their heart is the strongest muscle in their bodies. Their heart muscle could flatten the tennis ball once a second, 24-hours a day, for a lifetime! Read WHY-FLY's sign to them.

Home Base

Having a strong and healthy heart is an important part of being fit. Ask them what kinds of exercise they like to do. Have them make a list at home with an adult of some ways their families can exercise together to keep their hearts healthy.

Level A

Main Concepts: The heart is a strong muscle that pumps blood throughout our entire body. Blood carries the food and oxygen we need to stay alive. Exercise helps keep our hearts healthy.

Picture Activity

See TN Level Pre-A - PICTURE ACTIVITY.

Vocabulary

First go over all the pictures together - hat, hand, heart, hair. Then have them write the letter "h" in each heart and match each word with its picture.

Weekly Lab

See TN Level Pre-A - WEEKLY LAB. In addition, if you can obtain a real stethoscope and have a classroom pet (like a rabbit or guinea pig), try listening to its heart beat. As a rule, the smaller the animal, the faster the beat (e.g., a mouse's heart beats 600 times a minute).

Weekly Problem

Answers: 1) 70 2) 90 3) 100. (These are average counts and vary in individuals.) Practice counting by tens together before beginning this activity.

Writing for Science

Ask if they have ever noticed that their hearts beat differently at different times. Sometimes they may beat faster. Discuss the pictures. Can they remember some situations when their hearts beat faster? Have them write their stories on a separate piece of paper and draw pictures to accompany their stories.

Challenge

Try to get enough tennis balls so they can work in groups of 2 or 3. Have them try to flatten the ball with their hands. Tell them that their hearts are much stronger than their hands. In fact, their heart is the strongest muscle in their bodies. Their heart muscle could flatten the tennis ball once a second, 24-hours a day, for a lifetime! Read WHY-FLY's sign to them.

Home Base

Having a strong and healthy heart is an important part of being fit. Ask what kinds of exercise they like to do. Have them make a list at home with an adult of some ways their families can exercise together to keep their hearts healthy. Also, have them bring their exercise pictures back to class to share.

Level B

Main Concepts: The heart is our strongest muscle. It pumps blood throughout our bodies bringing the food and oxygen we need to stay alive. We need to eat well and exercise to keep our hearts healthy. (Please note that the left and right on the heart pictures are reversed, because they are facing you.)

Vocabulary

Answers: 1) heart 2) hair 3) mouth 4) chin. Have them add the missing letters to these "small" words to spell out these body parts.

Weekly Lab

Try to obtain a real stethoscope from your school nurse or other health professional, so your students can have an opportunity to hear their own hearts through this instrument. A word of caution: Real stethoscopes are very sensitive. Your students should be careful not to speak loudly into them or place them near a loud noise source. Have them compare listening from both ends of their "stethoscope." Were they able to hear any better when the cup was facing one way or another? Have them try putting cups on both ends, also. Another option is to use a turkey baster with the bulb removed or a kitchen funnel. (Remind them to be very careful and to gently place their ears near these, objects when listening!) Be sure the room is very quiet and have them listen for their partner's heartbeats in the middle of their chests, a little to the left of center. They may need to move their "stethoscopes" around a bit to find the best place to hear. As an extension, when they find their partner's heartbeat, time them for one minute, and have them count all the beats they hear. (Their hearts beat at about 90 beats a minute.) Explain that you can also feel your heart beat in places where your blood vessels are close to the skin. This is called your pulse. Demonstrate how to find their pulse in their wrists. Have them rest their arm facing up. Then place 2 fingers on their wrists, with a little bit of pressure, below the thumb area. Tell them to be patient and quiet and move their fingers only slightly until they find their pulse beat.

Weekly Problem

Answers: 1) 70 bpm 2) 90 bpm 3) 100 bpm 4) 120 bpm.

Writing for Science

Ask, your students whether they have ever noticed that their hearts don't always beat at the same rate. Ask them to discuss the pictures and to remember an experience that made their hearts beat faster. Have them write and then illustrate their stories.

Challenge

Try to get enough tennis balls so they can work in groups of 2 or 3. Have them try to flatten the ball with their hands. Tell them that their hearts are much stronger than their hands. In fact, their heart is the strongest muscle in their bodies. Their heart muscle could flatten the tennis ball once a second, 24-hours a day, for a lifetime! Have them read WHY-FLY's sign. For their pulse counters, have them find their pulse again as they did in the WEEKLY LAB. Then have them put their pulse counters on that spot. Tell them to keep their arms very still and watch their pulse counters carefully. (Adhesive "gum" or wax can also be used.)

Home Base

See TN Level A - HOME BASE. You may also want to discuss the importance of a low-fat, low-salt diet, rich in fruits and vegetables to help maintain a healthy heart. Heart disease is the leading cause of death in the U.S. About 32% of all deaths each year occur due to heart attacks and heart disease.

Level C

Main Concepts: The heart is our strongest muscle. It pumps blood throughout our bodies, bringing the food need to stay alive, through a system of tubes called blood vessels. (Please note that the left and right on the heart pictures are reversed, because they are facing you.)

Vocabulary

Answers: 1) heart 2) hair 3) mouth 4) chin 5) tongue 6) wrist. Have them add the missing letters to spell these body parts.

Weekly Lab

See TN Level B -- WEEKLY LAB. In addition, after they have found their wrist pulse, have them set their pulse counters on that spot and watch for the heart to "tick" in time with their pulse. Tell them to keep their arms very still and to watch carefully.

Weekly Problem

Answers: 1. Jen 2. Glen 3. Jen. As an extension, ask some other graph interpretation questions such as: "Who had a resting pulse rate of 90?" "What was Ben's pulse after exercise?" etc. Ask how their resting pulse rate compared with the others on the graph.

Writing for Science

See TN Level B - WRITING FOR SCIENCE.

Challenge

In this activity, they will make a simple heart valve model to demonstrate how the sound of a heartbeat is made as their heart valves snap close. Our heart valves keep our blood traveling in the right direction. Use a 3 oz. paper bathroom cup to make the valve. (The 5 oz. size cup has a lip on the bottom that will interfere with the intake.) Have them hold their cup closely over their mouth and chin area (like a seal), with both hands. Then have them inhale crisply a few times to make the flap snap down. The snapping closure, each time they suck in air, will make a sound like a heart beat. (Don't have them do this too many times without a break, to avoid hyperventilating.) Have them try to make their model "beat" once a second. That's about how fast their hearts beat! For the Tennis Ball Squeeze, try to get enough balls so [hey can work in groups of 2 or 3. Have them try to flatten the ball with their hands. Tell them that their hearts are much stronger than their hands. In fact, their heart is the strongest muscle in their bodies. Their heart muscle could flatten the tennis ball once a second, 24-hours a day, for a lifetime!

Puzzle

Have them follow the path through this circulatory system maze to see how blood flows around their bodies, starting and ending at the heart. Remind them that their blood picks up fresh oxygen from their lungs and carries it to all parts of their bodies. Then their heart pumps the blood back to their lungs to get more oxygen, before repeating this trip over and over again.

Level D

Main Concepts: The heart is our strongest muscle. It pumps blood everywhere throughout our bodies. Through a system of tubes called Mood vessels, our blood brings the food and oxygen our bodies need to stay alive. It is important to eat well and exercise to keep our hearts healthy. (Please note that the left and right on the heart pictures are reversed, because they are facing you.)

Vocabulary

Answers: DOWN - 1) muscle 2) fist 4) fats 5) heartbeat. ACROSS - 3) veins 6) exercise 7) arteries 8) blood.

Puzzle

See TN Level C - PUZZLE.

Weekly Problem

Answers: 1. Jen 2. Glen 3. Jen. Explain that you can feel your heart beat in places where your blood vessels are close to the skin. This is called your pulse. Demonstrate how to find their pulse in their wrists. Have them rest their arms facing up. Then place 2 fingers on their wrists, with a little bit of pressure, below the thumb area. Tell them to be patient and quiet and move their fingers only slightly until they find their pulse beat. You will need to time them for 1 minute while they do jumping jacks. Ask how their resting pulse rate and pulse after exercise compared with the others on the graph. Have them estimate what they think their pulse rates will be before they measure them. As an extension, ask some other graph interpretation questions such as: "Who had a resting pulse rate of 90?" "What was Ben's pulse after exercise?" etc.

Writing for Science

Ask if they have ever noticed that their hearts don't always beat at the same rate. Strong emotions like fear or excitement send chemicals into our bodies that can make our hearts beat faster. Ask them to discuss the pictures and to remember some situations that made their hearts beat faster. Have them write and illustrate two stories about two different experiences.

Weekly Lab

For Lab A - Stethoscopes: Try to obtain a real stethoscope from your school nurse or other health professional, so your students can have an opportunity to hear their own hearts through this instrument. A word of caution: Real stethoscopes are very sensitive. Your students should be careful not to speak loudly into them or place them near a loud noise source. Have them compare listening from both ends of their "stethoscope." Were they able to hear any better when the cup was facing one way or another? Have them try putting cups on both ends, also. Another option is to use a turkey baster with the bulb removed or a kitchen funnel. (Remind them to be very careful and to gently place their ears near these objects when listening!) Be sure the room is very quiet and have them listen for their partner's heartbeats in the middle of their chests, a little to the left of center. They may need to move their "stethoscopes" around a bit to find the best place to hear. Time them for one minute, so they can count heartbeats. Lab B - Heart Valve Model: In this activity, they will be making a simple heart valve model to demonstrate how the sound of a heartbeat is made as their heart valves snap close. Our heart valves keep our blood traveling in the right direction. Use a 3 oz. paper bathroom cup to make the valve. (The 5 oz. size cup has a lip on the bottom that will interfere with the intake.) Have them hold their cup closely over their mouth and chin area (like a seal), with both hands then have them inhale crisply a few times to make the flap snap down. The snapping closure, each time they suck in air, will make a sound like a heart beat. (Don't have them do this too many times without a break, to avoid hyperventilating.) Have them try to make their model "beat" once a second. That's about how fast their hearts beat! Lab C - Pulse Counter: Tell them to keep very still. Have them watch the heart on their pulse counters carefully to see it "tick" in time with their pulse beat. Lab D - Tennis Ball Squeeze: Try to get enough tennis balls so your students can work in groups of 2 or 3. Have them try to flatten the ball with their hands. Tell them that their hearts are much stronger than their hands. Their heart is the strongest muscle in their bodies. Their heart muscle could flatten the tennis ball once a second, 24-hours a day, for a lifetime!

Level E

Main Concepts: Our strong, muscular heart is a hollow four-chambered organ that pumps blood throughout our bodies. Our blood, which carries the food and oxygen our cells need to stay alive, travels through a system of tubes called blood vessels. It is important to eat well and exercise to keep our hearts healthy. (Please note that the left and right on the heart pictures are reversed, because they are facing you.)

Vocabulary

ACROSS - 1) chambers 3) fist 4) blood 6) valves 8) arteries 9) middle 11) heartbeat. DOWN - 2) muscle 5) oxygen 6) veins 7) exercise 10 fat.

Puzzle

See TN Level F - PUZZLE.

Weekly Problem

Answers: 1. Jen 2. Glen 3. Jen 4. Glen. Explain that you can feel your heart beat in places where your blood vessels are close to the skin. Demonstrate how to find their pulse in their wrists. Have them rest their arms facing up. Then place 2 fingers on their wrists, with a little bit of pressure, below the thumb area. Tell them to be patient and quiet and move their fingers only slightly until they find their pulse beat. You will need to time them for 1 minute while they do jumping jacks. Ask how their resting pulse rate and pulse after exercise compared with the others on the graph. Have them estimate what they think their pulse rates will be before they measure them. As an extension, ask some other graph interpretation questions such as: "Who had a resting pulse rate of go?" "What was Ben's pulse after exercise?" etc. Ask them to time how long it took for their pulse rate to return to its resting rate after exercise. Experts say the faster you recover, the more fit you are. Discuss the benefits of exercise, especially aerobics, for cardiac fitness.

Writing for Science

Strong emotions like fear and excitement release powerful chemicals into our bloodstreams that can make our hearts beat faster. Ask if they have ever read a "thriller." For this activity, they will be using the old stand-by "It was a dark and stormy night ..." as a story-starter for their "heart-pounding" tales. Have them discuss some personal experiences about when their hearts beat faster.

Weekly Lab

Lab A - Stethoscope: Try to obtain a real stethoscope from your school nurse or other health professional, so your students can have an opportunity to hear their own hearts through this instrument. A word of caution: Real stethoscopes are quite sensitive. Tell your students to be careful not to speak loudly into them or to place them near a loud noise source. A stethoscope is an amplification of the human eardrum. It works by bringing sound into the ear from its vibrating membrane (the latex square). Be sure the room is very quiet and have them listen for their partner's heartbeats in the middle of their chests, a little to the left of center. They may need to move their "stethoscopes" around a bit to find the best place to hear. Time them for one minute, so they can count heartbeats. For Labs B, C, and D - See TN Level D - WEEKLY LAB.

Level F

Main Concepts: see TN Level E. In addition, arteries carry blood from the heart out to the body. Veins carry our blood back to the heart and lungs. (Please note that the left and right on the heart pictures are reversed, because they are facing you.)

Weekly Lab

Lab A: Poor diet, obesity, and lack of exercise all contribute to heart disease. One serious sign of heart disease is clogged arteries. When the arteries that supply the heart muscle with blood become clogged, waste products build up. The muscle then "starves" and a heart attack can occur. In this lab, they will be making a model of a clogged artery. Use straw pieces about 5 cm (2 inches) long. Play-doh[R] can be used instead of clay. (You may want to add red food coloring to the water to simulate blood.) When gently squeezed, the water will flow out through both straws at different rates. Have them compare their "clogged" artery to the free-flowing one. Explain that the "fat" in their clogged straw is similar to what is in a real "clogged" artery. (Remind them not to squeeze with too much force, or they will push their straws out of the bottle.) Lab B: In this activity, they will be making a simple heart valve model to demonstrate how the sound of a heartbeat is made as their heart valves snap close. Use a 3 oz. paper bathroom cup to make the valve. (The 5 oz. size cup has a lip on the bottom that will interfere with the intake.) Have them hold their cup closely over their mouth and chin area (like a seal), with both hands. Then have them inhale crisply a few times to make the flap snap down. The snapping closure, each time they suck in air, will make a sound like a heart beat. (Don't have them do this too many times without a break, to avoid hyperventilating.) Have them try to make their model "beat" once a second. That's about how fast their hearts beat!

Weekly Problem

See TN Level E - WEEKLY PROBLEM. In addition, 4) about 20 beats. Discuss how Jen, with the lowest resting heart rate, is probably the most fit and has the pulse rate that rose the least after exercising. Conversely, Glen, with the highest resting pulse rate also had the highest increase after exercising.

Writing for Science

See TN Level E - WRITING FOR SCIENCE.

Challenge

For the pulse counter, tell them to keep their arms very still. Have them carefully watch the heart on their counters to see it "tick" in time with their pulse beat. Tennis Ball Squeeze: Try to get enough tennis balls so your students can work in groups of 2 or 3. Have them try to flatten the ball with their hands. Tell them that their hearts are much stronger than their hands. Their heart is the strongest muscle in their bodies. Their heart muscle could flatten the tennis ball once a second, 24-hours a day, for a lifetime!

Puzzle

Have them follow the path through this circulatory system maze to see how blood flows around their bodies, starting and ending at the heart. Remind them that their blood picks up fresh oxygen from their lungs and carries it to all parts of their bodies. Then their heart pumps the blood back to their lungs to get a new supply of oxygen, before sending it out to the body all over again.

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RELATED ARTICLE: DID YOU KNOW??

Your heart beats about 100,000 times every day of your life.

Heart disease kills more Americans than any other cause.

Your blood travels around your whole body in less than 1 minute and does this more than 1000 times every day.

Your heart beats more than 30 million times a year.

A canary's heart beats about 800 times a minute. A mouse's heart beats 600 times, a dog's heart beats 120 times, and an elephant's heart beats about 25 times each minute.

Your heart pumps about 3,600 gallons of blood every day!

Your heart pumps enough blood in a lifetime to fill 100 swimming pools.

Your heart will probably beat about 2 billion times in your lifetime!

Your blood travels around your whole body in less than 1 minute.

Your blood travels through your body more than 1000 times every day.

Your heart pumps about 2,625,000 pints of blood every year.

Heart disease kills more Americans than other cause.

Your body has over 93,000 miles (150,000 km) of blood vessels in it.

An adult's heart beats about 70 times a minute, a child's heart about 90, and a baby's about 120.

A canary's heart beats 800 times a minute. A dog's heart beats 120 times, and an elephant's heart beats about 25 times every minute.

RELATED ARTICLE: National Science Education Standards
Unifying Concepts and Processes (K-8)

* Systems, order, and organization
* Evidence, model, and explanation
* Constancy, change, and measurement
* Form and Function

Standard A: Science as Inquiry (K-8)

* Abilities to do scientific inquiry
* Understanding about scientific inquiry

Standard C: Life Science (K-4)

* The characteristics of organisms
* Organisms and environments (5-8)
* Structure and function in living systems
* Regulation and behavior

Standard F: Science in Personal and Social Perspectives

(K-4)
* Personal health (5-8)
* Personal health
* Risks and benefits
* Science and technology in society


RELATED ARTICLE: Heart Demonstration

For a Teacher Demonstration - you may want to order a beef heart, from the meat department of your grocery store, for your students to observe first hand. This is something many of them may never have seen before. All mammal hearts (including humans) have four chambers. For older students, you may also want to bring in a chicken heart for comparison. Birds have a two-chambered heart. (Of course, when handling uncooked meat products, be sure to wear rubber gloves and wash all areas well after use.)

RELATED ARTICLE: Initiating Questions (for Levels Pre-A - C)

1. Where is your heart? Put your hand on the spot. (It is in the middle of your chest, slightly to the left.)

2. What job does your heart do? (It pumps blood to your whole body.)

3. Have you ever felt your heart pounding or beating fast? When was it and why?

4. Do you know the name of the instrument a doctor or nurse uses to listen to your heart? (a stethoscope)

5. How big do you think your heart is? (It's about the same size and shape as your fist.)

6. Does your heart beat when you are asleep? (Yes, your heart beats all the time throughout your life.)

RELATED ARTICLE: The Heart

Your Heart

Pump! Pump! Pump! Did you ever think of your heart as a "jumpy" lump of muscle? In fact, your heart is the strongest muscle in your entire body. It is about the size and shape of your fist and weighs about a pound. You can feel it beating in the middle of your chest, slightly towards the left. Your heart is a pump made completely of muscle. When your heart beats, it pumps blood everywhere throughout your body.

Inside your heart are 4 hollow areas called chambers. On top are the 2 atriums and on the bottom are the 2 ventricles. The sound you hear when your heart beats is caused by the opening and closing of special one-way doors between the chambers. These are your heart valves. They keep your blood moving in the right direction.

Why Your Heart Beats

Your body is made of millions of tiny living building blocks called cells. These cells need food and air to stay alive. Your blood carries food from your intestines, and oxygen from your lungs, to all your cells through a system of tubes called blood vessels. Your blood also carries away all kinds of waste products from your cells. Blood is pumped from your heart, out to your body, through blood vessels called arteries. Then smaller vessels called capillaries deliver the oxygen and food to your hungry cells.

After going around your body, your blood travels back to your heart through blood vessels called veins. Your heart pumps this blood to your lungs where it picks up more oxygen. Once it has a new supply of oxygen, it travels back to your heart. Then it is pumped out into your body again, repeating the trip over and over. All these parts working together are your circulatory system.

A Healthy Heart

There are lots of ways you can help to keep your heart healthy. Get plenty of exercise and eat right. Enjoy healthy foods like fruits, grains, and vegetables. Try to avoid foods high in fat and salt, which can clog your blood vessels and cause high blood pressure. Of course, always stay away from cigarettes and tobacco!

When you visit your doctor's office, your heart will get a check-up! The doctor will use a stethoscope to listen to your heartbeat. You will also have your blood pressure checked with a blood pressure cuff. Getting regular check-ups is another important way to be "heart smart."

Vocabulary

Across:
1. The 4 areas in your heart.
3. Your heart is about as big as a --.
4. What your heart pumps.
6. The "one-way doors" in your heart.
8. The blood vessels that carry blood out to your body.
9. Your heart is in the -- of your chest.
11. A doctor uses a stethoscope to hear your --.


Down:
2. Your heart is the strongest -- in your body.
5. Blood picks up -- in your lungs to carry to your cells.
6. The blood vessels that carry blood back to your lungs and heart.
7. -- helps keep you heart healthy and strong.
10. To keep your heart healthy, avoid eating foods with lots of
 salt and --.


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Puzzle

Follow the path your blood takes around your circulatory system.

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Weekly Problem

A slower heart rate is a sign of fitness and a healthy heart. use the graph to answer these questions.
1. Who has the lowest resting pulse rate?

 Len Ben Glen Jen

2. Who has the highest pulse rate after exercise?

 Len Ben Glen Jen

3. Who has the pulse rate that went up the least after exercise?

 Len Ben Glen Jen

4. Who has the pulse rate that changed the most after exercise?

 Len Ben Glen Jen


5. Sit quietly and take your pulse for 1 minute. Then do jumping jacks for 1 minute and take your pulse again. Add your pulse rates to the graph. How do you compare to the others?

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Writing for Science

It was a dark and stormy night! I heard a thud!!! My heart was pounding. I could hear the blood rush past my ears, as I ......

Finish this story with an exciting ending that explains exactly what happened to make your heart race. Don't forget to illustrate your story, too!

Bonus: When have you felt your heart beat fast? Make a list of some of your heart-pounding experiences.

Weekly Lab

Try these heartbeats feasts!

You need: a small kitchen funnel, aquarium tubing, a square from a latex glove or balloon, duct tape, a 3 oz. paper bathroom cup, paper, a gumdrop or clay, a toothpick, a tennis ball, scissors, tape, pencil

Lab A: Make your own Stethoscope.

Step 1: Stretch the latex square over the mouth of the funnel and tape it securely.

Step 2: Push the aquarium tubing up through the neck of the funnel. Push it up high, but don't touch the latex. Tape it.

Step 3: Listen to a friend's heart. Move your "stethoscope" around, until you can hear the beating clearly. Count how many beats you hear in one minute. What spot was the clearest?

If you can, try listening with a real stethoscope. (Ask your school nurse.)

Lab B: Make your own heart valve.

Step 1: Trace the bottom of a 3 oz. cup onto some paper, adding a little flap. (See picture.)

Step 2: Cut this out and fold down the flap.

Step 3: Use your pencil to carefully poke a hole in the bottom of your cup.

Step 4: Put the paper circle over the bottom of your cup and tape the little flap down to the side of the cup.

Step 5: Hold the cup tightly over your mouth and chin with both hands. Now, suck in your breath sharply several times. Listen for the "lub-dub" sound of your valve closing.

Lab C: Make a Pulse Counter.

Step 1: Cut out this heart, tape it to a tooth. pick, and stick it in your gumdrop.

Step 2: Rest your arm on a table. Then use 2 fingers to find your pulse.

Step 3: Put your pulse counter on that spot. Watch it move with each beat!

Lab D: How strong is your heart muscle?

Step 1: Your heart is your body's strongest muscle. To see how strong it is, try squeezing a tennis ball until it is flat!

Step 2: Try pressing it between both your hands or down on a flat surface.

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Weekly RESOURCES

Helpful Sources for Planning Your Science Weekly Classroom Activities

Recommended Resources

There are lots of great books on the heart and circulatory system. Have your students check them out in your Library or Resource Center.

* American Heart Association. HeartPower: Teacher Resource Guides and Classroom Kits. (National Center) Dallas, TX: 1996 (1-800-AHA-USA1 and 1-800-611-6083)

* Parker, Steve. The Heart and Blood. New York: Franklin Watts Co., 1989

* Sandeman, Anna. Body Books: Blood. Brookfield, CT: Copper Beech Books, 1996

* Simon Seymour. The Heart: Our Circulatory System. New York: Morrow Junior Books, 1996

Internet Resources

* This is the website for the American Heart Association's HeartPower. You can also access their e-mail service at the website to ask questions and request materials.

* http://www.americanheart.org/Health/Lifestyle/Youth/heartpower/index

Franklin Institute Website * http://www.sln.fi.edu/biosci/heart.html

Public Health Service, NH * http//www.atlcard/com/pump.html

Materials Needed for Issue 5 - Wind Power

Pre-A, A - pencil with erasers, tape, scissors, push pins or straight pins, drinking straws, lightweight objects (e.g., paper clips, feathers, buttons, etc.)

B - pencils with erasers, tape, scissors, push pins or straight pins, drinking straws, paper

C - drinking straws, pencils with erasers, index cards, straight pins, scissors, glue (styrofoam cups and clay - optional), notebook paper

D - same as above, plus a compass, plastic wrap, masking tape or permanent marker

E - same as above, plus string, tape measure or ruler (optional - toilet paper tubes, cloth or paper streamers)

F - cardboard, strong thread, ping-pong balls, glue, tape, drinking straws, plastic wrap, clear tape, masking tape or permanent markers, string, tape measures or rulers
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Copyright 1998 Gale, Cengage Learning. All rights reserved.

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Title Annotation:includes teaching guide, games, puzzles and crafts; function and anatomy of human heart
Publication:Science Weekly
Date:Oct 16, 1998
Words:7086
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