2 Hear Your HeartBe sure to look for all of these books in the Let’s-Read-and-Find-Out Science serie: How Many Teeth? Sleep Is for Everyone Plants and Animals: ‘Acinals in Winter Baby Whales Drink Mil Big Tracks, Lite Tracks Ducks Don't Get Wet “ Fires in the Night From Caterpilar to Bucerfly From Tadpole to Frog How a Seed Grows ‘A Nes Full of Eze ‘Our Puppies Are Growing A Safe Home for Manateet Searfsh ‘What Color s Camoufage? What Lives in Shall? What's Alive? What's Ie Like to Be 2 Fish? Where Are the Night Animals? ‘The World Around U: Ar ls All Around You The Big Dipper Is There Life in Outer Space? Snow Ie Falling Sounds All Around ‘Whae Makes a Shadow? STAGE 2 ‘The Human Body: Germs Make Me Sik! Hear Your Heart The Skeleton inside You Why | Sneeze, Shiver, Hiccup, and Yawn Yur Skin and Mine Planes and Animals: Ant Ces Besa Friend to Trees Ching Crickets Corn i Maize How Do Apples Grow? How Do Birds Find Their Way! Look Out for Turles! Milk From Cow to Carton ‘An Octopus Is Amazing Snakes Are Huncers Sponges Are Skeletons Who Eats What! ‘Why Do Leaves Change Color? Why Frogs Are Wet Zipping. Zapping. Zooming Bats Dinosaurs Digging Up Dinosaurs Dinosaur Babies Dinoraur Bones Dinosaurs Are Diferent Fossil Tall of Long Ago My Visi to che Dinosaurs Terrible Tyrannosaurs What Happened to the Dinosaurs? ‘Space: Floating in Space “The International Space Station ‘The Moon Seems to Change ‘The Planets in Our Solar System “The Sky Is Fl of Stars What Makes Day and Night What the Moon lr Like ‘Weather and the Seasons: Down Comes the Rain Feel the Wind Fash, Crash, Rumble, and Roll ‘Tornade Alert What Wil the Weather Be? ‘Our Earth: Archaeologists Dig for Ches Earthquakes Follow the Water from Brook to Ocean How Mountains Are Made Lets Go Rock Collecting, 8 Spit Voleances Yeuire Aboard Spaceship Earth ‘The World Around Us: Day Light, Nigh Light Switch On, Sith OFF Wat is the World Made OF What Makes a Magnet? Where Does the Garbage GoLET'S-READ-AND-FIND-OUT SCIENCE® Hear Your by Paul Showers © illustrated by Holly Keller HarperCollinsPublishersFor Marie-Laure, with thanks HK. With special thanks to Richard A. Manzi, M.D., for his time and expert review The Let's Readand-Find-Oue Science book series was originated by Dr. Fanklyn M. Braley, Astronomer Emeritus and former Chairman of the American Museum-Hayden Planetarium, and was formerly co-edited by him and Dr. Roma ‘Gans, Profesor Emeritus of Childhood Euvcation, Teachers College, Columbia University Text and illsteatons for ‘each ofthe books in the series are checked for accuracy by an exper in the relevant field. For more information about Lets Read-and-Find-Out Science books, write to HarperCollins Children's Books, 1350 Avenue of the Americas, New York, NY 10019, or visit our we ste at www.letsteadandfindout-com HarperCollins, and Lets Read-and-Find-Out Science® are trademarks of HarperCollins Publishers Inc Hear Your Heat ‘Tent copyright © 2001 by Kate Showers Illustrations copyrighe © 2001 by Holly Keller “Text sas originally published in. 1968 with illustrations by Joseph Low ‘Manufactured in China, All ights reserved Library of Congress Cataloging-in Publication Daca Showers, Pal Hear your heart by Paul Showers: ilustrated by Holly Kelle. p.cm—(Let-read-and-findout science. Sage 2) ‘Summary simple explanation ofthe tutte ofthe heat axl how it works. ISBN 0.06.025410-6.—ISBN 0.06.025411-4 (lib. eg) —ISBN 0.06-445139-9 (pbk) 1 Heare—Juvenil literature, [0. Heart] 1. Kells, Holly ill UL Title. Il. See. QPILL6S48 2001 9941336 61LV7—Ae2 ae ‘Typoaraphy by Elynn Cohen 59 1 © Revised and Newly Mluscrated EdtionHear Your HeartWren 1 visit the doctor, he listens to my heart with a stethoscope. The stethoscope is cold. It makes me shiver.I like my stethoscope much better. It isn’t cold. My stethoscope is a cardboard tube. My sister, Lisa, has one, too.We save tubes and turn them into stethoscopes. Sometimes they are tubes from old rolls of paper towels. Sometimes they are tubes from old toilet-paper rolls. Any kind of cardboard tube will do. This is how you listen to someone’s heart: Ask a friend to find the heartbeat on the left side of her chest. Put one end of your tube on this spot. Now put your ear at the other end. se 0 ehWe listen to our friends’ hearts, and they listen to ours. Phil’s heart beats like this: pum-PUM pum-PUM pum-PUM pum-PUM. Molly’s heart beats the same way. So does mine. So does Lisa’s.Dad’s heart is a little slower. It beats like this: ka-DUM ka-DUM ka-DUM ka-DUM.Andrew is only eleven months old. Mom holds him so we can listen to his heart. Andrew’s heart has a very quick beat. It goes: tup-pa tup-pa tup-pa tup-pa tup-pa.Put your hand on your chest. Can you feel your heart?12 Your heart is full of blood. When it beats, it squeezes itself together. That’s when the heart contracts. Blood squirts out into some of the tubes. Then your heart stops squeezing and opens up again. That’s when the heart expands. Blood flows into it through the other tubes. Blood flows away from your heart in tubes called arteries. Blood flows into your heart in tubes called veins. In this picture the arteries are colored red. The veins are black.Dera taatie erotics Night and day it’squeezes opens Reiisanes opens, ae liwency beat Aa (OV,A heart is divided into two halves. Each half has several veins and one artery attached to it. Each half has two little doors in it. These doors are called valves. In this drawing the valves to the arteries are colored red. The valves from the veins are black. 1516 All day long, all night long, these valves open and close, open and close... When the black valves open, the red valves close. When the red valves open, the black valves close. The valves keep the blood moving in the right direction—IN from the veins, OUT through the arteries.18 When a heart beats, each half works the same way. First, blood comes in from the big veins at the top of the heart. The black valves are open. Blood flows into the heart.Then the heart contracts and pushes the blood. The black valves close. The red valves open. Blood cannot flow back into the veins. It can only flow out through the arteries. 19Big arteries spread out from your heart. They go to your arms and legs and head. Smaller arteries branch out from the big ones. They branch out to the top of your head to the tips of your fingers to the tips of your toes to every part of your body. When blood reaches the very smallest arteries, it passes into tiny veins. The tiny veins run into bigger and bigger veins that carry the blood back to the heart. 20oe DEAT- Pusy s — oe De,Touch your wrist just below your thumb. Press gently with your fingertips. Do you feel something push against your fingers? push push push. You are feeling-a small artery in your wrist. Your heart is pushing blood through it: beat—push beat—push beat—push. This is your pulse. You can only feel your pulse in an artery. You can see your veins, but you cannot feel a pulse in them. 23Your pulse tells you how fast your heart is beating. How fast is your heart beating right now as you read this book? Get a watch with a second hand and count your pulse. How many times does your heart beat in one minute?A man’s heart beats about 72 times a minute: ka DUM _ka-DUM ka-DUM ka-DUM. An eight-year-old’s heart beats about 90 times a _ minute: pum-PUM pum-PUM pum-PUM pum-PUM. IN baby’s heart beats more than 120 times a minute: tup-pa tup-pa tup-pa tup-pa tup-pa. is, Sometimes it goes a little faster, sometimes a little slower. o.26 Your heart beats faster when you exercise. Try this and see for yourself. Hop up and down on one foot twenty times. Now feel your pulse. Use your watch to count your pulse. How fast is your heart beating now?When you sleep, it beats much slower. |oS, fe ae (es ¢ ee oe : i er ae [a ec ee — agen OE home ee OR ee | (te ee ee ee Be eee oa Vie gee ee / eee es ee NE ness Ce bs = eet : ee 0 Eee So | Eee ie I Nee =~ (Ni \\j 2A mouse’s heart beats more than 500 times a minute. Lisa has a parakeet named Clarence. When we hold him gently, we can feel his heart beating: Pat-pat-pat-pat-pat. It beats so fast, we can’t keep count.Your heart works all the time. No other part of your body works as hard. Your hand is strong, but not as strong as your heart. Try this: Open your hand. Close it in a fist. Open it. Close it. How long before your hand gets tired? 30oP : your heart keeps moving blood through your body.FIND OUT MORE ABOUT YOUR HEART How to Measure Your Heart Rate 1. Hold out the middle and index fingers of one hand together. 2. Place them on your other wrist at the base of the thumb until you feel a soft beating. You may have to try a few different spots until you find the right one. 3. Have a friend time you as you count the number of beats for one minute. This is your resting heart rate. > How to Exercise Your Heart You and a friend can try something fun to exercise your heart: Invent a new dance to your favorite song. Count how many jumping jacks you can do in one minute. Play a game of tag. Go roller-skating. Play catch. Do one or a couple of these activities for twenty minutes. When you are finished, count your heart rate again. Your heart rate will be higher (there will be more beats per minute). This is because exercising makes your heart beat faster, helping it stay healthy and strong. It is important to exercise a few times each week for at least twenty minutes. Not only will it keep your heart strong, it will keep your body strong as well.* How to Make a Stethoscope You don’t have to be a doctor to hear someone’s heartbeat. You can make your own stethoscope at home. You will need: 1 cardboard tube from an empty paper-towel roll 1 friend . Your friend can find his or her heart by placing one hand flat on the left side of his or her chest and feeling for the beat. . Place one end of the tube on the spot where your friend felt his or her heartbeat. - Put your ear at the other end of the tube, and you will hear your friend’s quiet heartbeat. 4. Let your friend have a turn listening to your heart. Web Site Visit this web site to find out more about your heart and how you can keep it healthy: hetp://www.americanheart.org/Health/Lifestyle/Youth.A journalist and an author of books for young readers, Paul Showers worked for many years on the staff of The New York Times. He is the author of THE LISTENING WALK, and his books in the Let’s- Read-and-Find-Out Science series include SLEEP Is FOR EVERYONE, WHAT HAPPENS TO A HAMBURGER, and YOUR SKIN AND MINE. Holly Keller is the author-illustrator of the Geraldine books and the Horace series. Among the Let’s-Read-and-Find-Out Science books she has illustrated are SOUNDS ALL AROUND and FROM TADPOLE TO FROG, both by Wendy Pfeffer, and sNOW Is FALLING by Franklyn M. Branley. Holly Keller lives in West Redding, Connecticut.LET'S-READ-AND-FIND-OUT ABOUT 2: Your Heart | oR wh Night and day, whether you're asleep or awake, 7 insiv® your heart is always beating. ! Read and find out how your heart works and how to keep it healthy. Other Stage 2 books you might enjoy: Hunters 1 Faia Lauber: usted by Hoty Keer Introduce basic science concepts to young children and help satisfy their curiosity about how the world works. 4arperTrophy® Stage | books explain simple Stage 2 books explore more Banas 970.0 Nga seo9 fee Se, (2) eee sails sub ean \/ and linderpreeers children the promay gpd Find out more at wwrw.letsreadandfindout.com. 006s