Human Body Author: Dr. Bipasha Choudhury US_001_Half_title.indd 1 30/03/2017 15:50 Contents Editors Kathleen Teece, Kritika Gupta Designer Emma Hobson 4 Inside out Design assistant Bettina Myklebust-Stovne Project art editor Yamini Panwar 6 Growth US senior editor Shannon Beatty Managing editors Laura Gilbert, 8 The bare bones Monica Saigal Managing art editors Diane Peyton Jones, Neha Ahuja Choudhry 10 The skull Pre-production producer Marina Hartung Producer Isabell Schart 12 The brain Art director Martin Wilson Publisher Sarah Larter 14 Nervous system Publishing director Sophie Mitchell Educational consultant Jacqueline Harris 16 Muscle power First American Edition, 2017 Published in the United States by DK Publishing 345 Hudson Street, New York, New York 10014 18 Organs Copyright © 2017 Dorling Kindersley Limited DK, a Division of Penguin Random House LLC 17 18 19 20 21 10 9 8 7 6 5 4 3 2 1 20 Heart to heart 001– 299030–Sept/2017 All rights reserved. Without limiting the rights under the copyright reserved above, 22 Breathe in no part of this publication may be reproduced, stored in or introduced into a retrieval system, or transmitted, in any form, or by any means (electronic, mechanical, photocopying, 24 Blood recording, or otherwise), without the prior written permission of the copyright owner. Published in Great Britain by Dorling Kindersley Limited. A catalog record for this book is available from the Library of Congress. ISBN 978-1-4654-6308-1 DK books are available at special discounts when purchased in bulk for sales promotions, premiums, fund-raising, or educational use. For details, contact: DK Publishing Special Markets, 345 Hudson Street, New York, New York 10014 [email protected] Printed and bound in China All images © Dorling Kindersley Limited For further information see: www.dkimages.com A WORLD OF IDEAS: SEE ALL THERE IS TO KNOW www.dk.com Heart Brai F n et Tongue-rolling us 2 US_002_003_Contents.indd 2 04/05/2017 14:07 Contents 26 Immune squad 48 Emotions 28 Healing 50 Skin bacteria 30 Digestion 52 Bacteria... or virus? 32 Getting energy 54 Exercise 34 Teeth 56 Superhuman 36 The body clock 58 Human body facts and figures 38 Genes 60 Glossary Toot h 40 Senses 62 Index 42 Eyes 64 Acknowledgments 44 Hearing 46 Taste and smell S toma c h Red blood cells M k ull u S s cl e s D N A 3 US_002_003_Contents.indd 3 26/04/2017 10:40 The cell The cell is the smallest ! WOW! living part of the body. Different cells do different jobs. There are over 37.2 trillion cells in an average human. Tissues Similar cells form tissues. There are four tissue types in Tissues in the liver the body, including do similar jobs, like muscle tissue. get rid of poisons in food. Inside out The body is made up of 300 bones, 24 Organs organs, 11 organ systems, and at least Similar tissues join together 26 ft (8 m) of bowel! The brain controls to form organs, like the heart and kidneys. everything to help them work together. The skin is a strong waterproof wrapping paper that keeps the body together in a neat shape. 4 US_004_005_Inside_Out.indd 4 30/03/2017 14:39 WOW! Organ system Organs that carry out similar jobs make up organ systems such as the digestive system. The body The different organ systems join together to make one individual human being like you! The cell Cytoplasm is a soupy Digestive organs Cells are made up of even mixture in help break down tinier structures that work the cell. food for the body. to help the cell do its job. The plasma membrane surrounds each cell. It is Plasma The nucleus like a fence that controls membrane controls what comes into the cell. the cell. Structure of a cell 5 US_004_005_Inside_Out.indd 5 30/03/2017 14:39 Growth 12 years old Bones continue to grow so the child gets taller. They Bones start to form at around six weeks should do exercise to make their bones stronger. old in the womb and continue to grow into adulthood. As bones become longer, muscles grow and get stronger. Organs get bigger and we get heavier. Bone cells Infant harden into Embryo strong bones. Babies usually start to walk at Life begins as a ball of around the age of one. Many cells called an embryo in of their bones are very soft. the mother’s womb. The cells divide so that there are more cells to form a fetus. The fetus is curled up in the womb. A six-week-old embryo is Many bones around 2⁄25 in join together (5 mm) long. as infants age. Fetus It takes nine months to Four years old grow a baby. While it is in the mother’s uterus, it is Most of the soft bones from Hormones tell the bones to called a fetus. infancy have hardened by keep growing. the age of four. 6 US_006_007_Growth.indd 6 04/05/2017 14:14 Bone shapes Adult An adult is fully grown from We have different shapes of bone that around the age of 18. This help us to move in different ways. Each means their bones will not shape is made to match the job of the grow any longer. bone in the body. Small bones allow lots of movement. Other bones are made to support us and give us strength. These small bones are inside the always-moving hands and feet. Square bone These strong bones inside the spine support lots of muscles. Irregular bone This long bone is inside the arm, others are found in the leg. Long bone The sesamoid bone in the kneecap is shaped like a We shrink a little in old sesame seed! age as the discs in our back get squashed. Sesamoid bone 7 US_006_007_Growth.indd 7 30/03/2017 14:38 s es. al e X-rays show bones in white because they are the most solid parts. SpineThis column that runs up your back imade up of 33 bonIt protects the spincord connecting thbody and brain. en b ao endeisnI o X-rayX-ray photos show bones through the skin. A doctor will take an X-ray if they think you have broken a bone. Carpalselciv Ulna b enipS Pelvis a l C ull k S Spine s s one ther and otect soft store ortant jobe makes xygen n bones Humerus Ribs Radius The bare b Bones keep your body parts togehold everything upright. They prorgans, such as the heart. Bones calcium, which is needed for impin the body. Marrow inside a bon new red blood cells, which take oto our body parts. Muscles pull oto make you move. CartilageSquishy cartilage connects bones together that need to move, such as ribs for breathing.Cartilage in blue esurrounded by galother tissue.itrac edisnI tnioj eenK US_008_009_The_bare_bones.indd 8 30/03/2017 14:40