One Million Things - A Visual Encyclopedia

["Herring gull eat northern div pipit Gr Meadow ammer er Emu gbirdNightjar C er thrush Song etti\u2019s warbl 8 Chough Kiwi 9 11 andpiper grouse Chicken Red Common s Yellowh y owl Rub y-throated hu10mmin Tawn Dunno ck Newly hatched ostrich chick Brushland tinamou 7 CUCKOO 8 KIWI 9 COMMON SANDPIPER 10 HUMMINGBIRD Cuckoos lay single eggs in the A kiwi is 20 times smaller than an Sandpipers are shorebirds that lay Hummingbirds lay the smallest of all nests of other birds, and their emu, yet their eggs are almost the their eggs in shallow scrapes on birds\u2019 eggs. The bee hummingbird\u2019s color varies to match the host same size. This means that the egg is the ground near the water. Their egg is the size of a pea, because bird\u2019s eggs. When the cuckoo huge compared to the kiwi that lays pointed shape allows them to be the bird itself is no bigger than hatches, it heaves the other it, at up to a quarter of her weight. pushed together in a tight clutch a large moth. This ruby-throated eggs out so it can eat all the That\u2019s like a human mother giving to take up less space. The eggs are hummingbird\u2019s egg is bigger but still food its foster parents collect. birth to a three-year-old child. camouflaged by speckled patterns, tiny compared to the ostrich egg. and can be hard to see\u2014but if you do find any birds\u2019 eggs, remember it 11 CHICKEN is illegal to collect or disturb them. The egg that everybody recognizes is laid by the domestic chicken. We eat 1.1 trillion of these eggs every year. 49","MOVEMENT 1 The feature that makes animals so different from other living things is their ability to move. Some do not move much\u2014a sea anemone, for example, is sedentary (remains in one place) and catches anything that touches its tentacles. Most animals, however, travel to look for food, find breeding partners, or escape from their enemies. They slither, crawl, walk, hop, run, swim, and fly, sometimes at incredible speed. Some have evolved other amazing ways of getting around, like the insects and spiders that walk on water and the extraordinary sidewinding rattlesnakes. 3 2 1 GIBBON Although gibbons can walk well, they usually move through the forest by using their long, powerful arms to swing from the trees. They hurl themselves from branch to branch with astonishing speed, agility, and elegance. 2 SNAKE 8 7 A typical snake slips along by curving its flexible body around plants and stones and pushing the curves toward its tail. Sidewinders like this desert viper have a more baffling method, looping sideways over the sand like rolling springs. 3 OCTOPUS An octopus normally hauls itself over the seabed using its long, elastic arms. But it can shoot away from danger by jet propulsion, drawing water into its body and blasting it out at high pressure. Cuttlefish and squid do the same. 4 PENGUIN 5 FISH 6 STARFISH 7 SNAIL All penguins are superb swimmers, Most fish have flexible bodies that A starfish can curl its arms, but it The muscles in a snail\u2019s foot using their wings to \u201cfly\u201d through allow them to move through the actually creeps over the seabed contract and expand to create a the water, but they walk clumsily. water using their fins for stability using hundreds of tiny \u201ctube feet\u201d rippling movement that pushes On snowy slopes, they often prefer and to control their direction. on its underside. Each tube foot is the snail forward. Glands in the to toboggan on their well-padded Some fish, such as tunas, propel pumped full of water and is foot produce a slimy mucus to bellies, pushing themselves along themselves at high speed using extended and moved by changes make the track slippery. The slime with their stoutly clawed feet. just their tails. in water pressure. also protects the snail from debris. 50","6 5 4 11 9 10 8 WATER STRIDER 9 CHEETAH 10 BARN OWL 11 KANGAROO The water molecules at the surface The fastest of all land animals, a Birds are the masters of the air. A leaping kangaroo uses the elastic of a pool cling together to form an cheetah can run at an astonishing Most, like this barn owl, use their tendons in the backs of its legs like elastic film, strong enough to 60 mph (95 km\/h). It achieves this powerful feathered wings to drive the springs of a pogo stick. Every support tiny animals like this water by flexing its back to extend its themselves forward. Others can time it lands on its long feet, the strider. Its special brush-tipped feet stride as it bounds forward on its travel long distances by soaring on tendons stretch like rubber bands just dimple the surface, so it can long legs, but it can keep this pace rising air currents like gliders, then spring back again to catapult skate around without sinking. up for only about 40 seconds. without beating their wings at all. the kangaroo forward. 51","LIVING TOGETHER Animals and plants often rely on other living things for survival. Food, shelter, and pollination are some of the clearest examples of this. However, some animals and plants have much closer relationships. They can be partners, providing things like food or protection for each other. Some tag along with others without providing anything in return. Many do worse, latching on to other organisms as parasites, which can harm or even kill their often helpless hosts. The microscopic algae 1 that live in partnership with this coral provide its vivid color 2 huomffitmtfhlfieonTowhgsrwibetshirorleordisdnlao-gbn,piglteluerbbdfieullcltar 3 syeruxfcprhoAyamnhntogstnhepeerfyioordtreeesnwcwtemetheiete,saipnhids 4 This cuckoo chick has outgrown both the host bird and its nest, but it still cries out for food A strangler vine uses a tree for support but eventually kills it by competing for food and light 52 5","1 CORAL Corals trap prey in their stinging 6 tentacles. They pass some of the nutrients from their victims to tiny algae living in their tissues. These use the sun\u2019s energy to make sugar, and they pass some of this food back to the corals. An impala 2 HUMMINGBIRD welcomes the attention Hummingbirds gather flower nectar, of a red-billed and in the process they carry pollen oxpecker from flower to flower. Some plants searching for have evolved flowers that match the tasty parasites bills of particular hummingbird species, to encourage the birds to visit them A remora clings to and deliver their pollen efficiently. a shark\u2019s skin using a special sucker on 3 ANTS AND APHIDS the back of its head Aphids are tiny insects that feed on sugary plant sap. They must eat a lot of it to get enough protein, and they excrete the excess sugar as drops of sweet honeydew. Ants love to drink this, so they \u201cfarm\u201d the aphids, protecting them from predators, ensuring a constant supply. 4 CUCKOO Cuckoos are \u201cbrood parasites\u201d\u2014they lay their eggs in the nests of other birds. Each young cuckoo hatches quickly and destroys any other eggs in the nest, so it can eat all the food brought by its foster parents. It soon outgrows its hosts, who often do not seem to notice its massive size. 5 STRANGLER VINE Some slender rain forest plants, such as figs, grow by encircling a tree and slowly killing it\u2014a process that can take up to 150 years. They steal the tree\u2019s nutrients, and eventually the tree dies and decays, leaving the fig plant standing alone. 6 OXPECKER Hoofed grazing animals, such as impalas, are often plagued by tiny bloodsuckers, such as ticks, that they cannot remove by scratching. In Africa, stout-billed birds called oxpeckers do the job for them by picking the parasites off their skin and eating them. 7 REMORA Predatory sharks have very sharp teeth that cut their prey to shreds. The scraps are eagerly devoured by fish called remoras, which travel with the sharks by clinging to their skin. 7 They do their hosts no harm, and the sharks seem to ignore them. 53","MAMMALS Mofbaunnaarcirmmmkybimaoloklrsan.ulheSsnasoa)it.mrrielMyt,ewhua, elnanirkyylmieokeuhe-abtnualpglomlloaaoadrntnehetssdea,,rbewclavrehteetbairolttoeeuetborhaerttahspstetleoahrslnsia(dttapsfnfreoaeienmoydddoat.mlnhMseoweoiatrhisttbt.heaarrbeies ECHIDNA \u25b6 The echidna and the equally strange mapmAlamtbyaapblusystheacarhetildtahnyeaeolginvgelsys. on milk produced by mother for up to six its months. The mother eats food such as \u25b2 MOUSE all mammal species are eadrwitghiswthforohrmmerst,lohwnehggicrshonuoshnuedt. Nearly half of rats, rodents\u2014a group that includes mice, beavers, porcupines, and squirrels. The house mouse is the only mammal, aside from humans, to live on every continent. \u25c0 ELEPHANT Elephants use their sensitive trunks to gather coarse vegetation, which they grind to pulp with their massive teeth. They are the biggest land animals and are very intelligent. KANGAROO \u25b6 \u25b2 BAT Marsupials such as Bats are mammals that can fly. Some eat kangaroos give fruit, but most species, like this long-eared birth to tiny young bat, catch insects. They are nocturnal that are only (active at night) and locate prey in the dark by emitting high-pitched clicks and half formed. The listening for echoes from their target. newborn crawls into a pouch on its mother\u2019s belly to drink milk and grow into a fully developed baby kangaroo, or joey. 54","\u25c0 TIGER like the tiger eat other Powerful hunters mammals and birds. They have long, daggerlike canine teeth for killing their prey and scissorlike cheek teeth for slicing through hide and meat. \u25b2 MOLE Moles are specially adapted to their underground environment. They have strong claws for digging and very sensitive whiskers, which compensate for their poor eyesight. \u25b2WksmtswiaulhKolirielamvfsIra.leLemcwTmLsehihEeanetanngoRyltdewscb,WodroilemtoifvhaHletepthuhhAitepneoiin-LrtaatsEhphn,ireoeld.ikw-odeceoetrwahfuninsl, \u25c0OttthhhuGeeartmgOclloioavRrmseieIlslLmsatiL\u2014narAletsahlaapetrliearvaneaitsnpeaefamsotlroeiekrnsetgs of tropical Africa. HTmimhnhIaoaePrsssitvPhstiehiovOpreefspPlilyaotaOsnprbgtdouTiemtilAalsattemkMpmewulsaosUa.nulTsltSptohheewe\u25b6anoitdnfesgr any land mammal. 55","SLEEP Bats sleep while hanging upside down by their Animals sleep to save energy, rest their muscles, and allow feet in caves, tunnels, their brains to process the information that they pick up while cellars, and from trees awake. Some hunting animals sleep a lot, because they devote only a few hours each day to looking for food. Animals that are 1 hunted spend much more of their time awake and alert. 3 1 Bats sleep for about 20 hours 11 Sheep are descended from wild Seals sleep for a day, often in large colonies. animals that needed to stay awake around six hours to escape predators, so they sleep every day 2 Two-toed sloths are awake for for less than four hours a day. only four hours a day. Like bats, 6 they can cling to branches with 12 Kinkajous are raccoonlike their claws while fast asleep. animals that forage for food at night and sleep all day for about 3 Gorillas like to have about 12 hours. 12 hours of sleep a day. 13 Armadillos sleep for 4 Horses need just three hours 18 hours a day, curled of sleep a day. up in their burrows. 7 5 Elephants stand up for two of 8 the four hours a day they sleep. They have to lie down for the 11 dreaming stage, when their muscles are too relaxed for them to stay on their feet. Large plant- eating animals tend to get less sleep than smaller animals, because they have to spend so much time looking for food and eating. 6 Seals often sleep on rocks and 21 beaches, but they can also 14 sleep floating upright at sea, or even under 23 water, surfacing to breathe without 24 waking up. 16 Red foxes sleep for about 10 7 Wolves may sleep hours, mostly during the day. Like for up to 14 hours a many hunters, they are more active day, especially if they at night when they track their prey have had a big meal using their sensitive noses and ears. after a successful hunt. 8 Pigs need eight hours of sleep a day, just like adult humans. 9 Bears also clock up about 22 15 Echidnas are egg-laying eight hours of sleep a day. mammals that sleep for about 14 Human babies need 15 hours 14 hours a day. Scientists believe 10 Tigers sleep for up to 16 hours, of sleep a day. We sleep less as we they do not have phases of dream since they can catch all the food get older, so adults sleep for an sleep like other mammals. they need within a very short time. average of eight hours, and elderly people for less than six hours. 56","2 4 5 22 Chinchillas sleep in burrows for 10 about 13 hours a day, high in the Horses can sleep mountains of South America. standing up without toppling over because 23 Rabbits sleep for about eight their legs lock in place hours, mainly during the day. They prefer to feed at night when they 9 are not so vulnerable to predators. 24 Chimpanzees normally sleep for 10 hours a day, but baby chimps sleep for longer. 25 Baby gorillas need more sleep than their parents and may sleep or doze for more than 15 hours. 26 Hedgehogs usually sleep for 10 hours during the day. In winter, they hibernate (spend the cold months in a sleeplike, inactive state). Dogs have similar sleep patterns to humans 12 13 17 15 16 20 19 25 18 26 17 Koalas eat tough eucalyptus 18 Dogs sleep for 10 hours a day. 20 Cats often sleep for 15 hours a 57 leaves that are hard to digest and day. Wild cats are most active provide little energy, so they spend 19 Red pandas, which are like during the night. about 15 hours a day sleeping and bamboo-eating raccoons, sleep for another five hours dozing. about 11 hours a day. 21 Lions sleep for at least 13 hours. While they sleep, other animals feed near them without risking attack.","Gharial crocodile Crocodile teeth are all Gannet the same shape and can be replaced by new ones more than once CROCODILE \u25b2 Merganser ligthhBtewobneiyrigdjha\u2019stwhbsoislrlunpy,port One of the closest living relatives of the dinosaurs, crocodiles have long jaws Hamster studded with many sharp-pointed teeth for seizing their prey. The fish-eating Badger gharial of Indian rivers may have more than 100 teeth. Tawny owl anbdiBghrsoueagndesisetkiyvueelslehaorus ses Mallard Blackbird Rabbit Armadillo Long bill of a Am Curlew curlew allows azon parrot it to probe prsotrtToehcnitngtcherneaonbuirugamihntisojustHedgehog deeply into soft mud to catch worms PARROT \u25b6 FROG \u25b6 Frog All birds have thin, light skulls, which The skull of a frog is broad, makes flying easier. Their beaks or bills are much lighter than toothed providing plenty of room for jaws. They are not built for chewing, yet the bills of some parrots are its large eyes and giving it an strong enough to crack nuts. extremely wide mouth. This allows it to swallow its prey whole, so it does not need a set of teeth for chewing. Deep ridge on back \u25c0 LION Collie dog of skull anchors massive muscles Lion Like all cats, the lion is a dedicated attached to jaw hunter. It has short, powerful jaws with huge stabbing canine teeth at the front 58 and meat-slicing carnassials at the back.","The big eyes of this powerful, fast-swimming predator are contained in large sockets Anjtaewatsleoarnnsgdhntaeoovxnettgreleouemnethsgeblayut tall Anteater \u25bc ANTELOPE BARRACUDA \u25b6 Barracuda Massive jaws are armed with needle-sharp teeth Some animals, such as antelope and Fish have quite strong for a secure grip on prey cattle, have massive horns on their skulls, but the various heads for defense and fighting parts are not fused rivals. Male deer grow antlers, which together like those of they use to impress females and mammals. The jaws of fight each other, but these antlers many fish are separate fall off at the end of the mating from the brain case but season. Each male grows attached by bones that a new pair every year. allow them to be thrust forward to seize prey. Strong bony cores \u25bc BABOON are sheathed with Furry skin tough outer layers (velvet) Close relatives of humans, baboons have similar of ridged horn skulls but longer jaws and bigger back teeth. nourishes the This is because they eat large quantities of grass, Antelope antler as it which requires a lot of chewing. They also have long, sharp canines, which they use to kill animals grows and is for food and to fight among themselves. shed in Baboon Eye sockets at front the summer of skull allow the baboon to see things Deer in three dimensions Long snout allows Nasal cavity contains thin antelope to nibble scroll-like bones, which grass while keeping support the membranes watch for danger that detect scent Sharp, bladelike incisor SKULLS teeth on lower jaw are ideal for cropping grass Most vertebrates (animals with backbones) have strong bony skulls. They are made up of cranial bones that and gathering leaves protect their brains, jaw bones that support their teeth or beaks, and face bones that contain their eye sockets and nasal cavities. The whole structure can be quite heavy and is supported by strong neck muscles. 59","BLOOD CELLS Magnified 13,500 times, this is a false-color SEM (scanning electron micrograph) of human blood. Red blood cells (red) carry oxygen, while white blood cells (yellow) are involved in the body\u2019s immune system. 60","Human body 61","CELLS A macrophage \u201creaches out\u201d to The body is constructed capture bacteria from trillions of tiny living (blue), which it will units, known as cells. There are more than 200 different then digest types of cells\u2014and each has its own shape, size, and specific job to 2 do. Typically, cells of the same type work together in units called tissues. Each individual cell is surrounded by a thin membrane that regulates the movement of nutrients and other substances in and out of the cell. Cells multiply by continually dividing into two identical \u201coffspring.\u201d This division allows the body to grow and to replace cells that are damaged or worn out. 1 62","Epithelial cells lock Spiky osteocyte lives in Bone matrix is made 1 NERVE CELLS together to form the a lacuna, or space, in of hard calcium salts protective, pitted lining the bone matrix and more flexible Found in the brain, spinal cord, and of the stomach collagen fibers nerves, nerve cells, or neurons, carry and process high-speed electrical signals, 3 called nerve impulses. These impulses coordinate body processes and enable 5 us to feel, think, and move. 2 WHITE BLOOD CELLS Circulating in blood, and in a clear fluid known as lymph, white blood cells help defend the body against disease. The cells include macrophages and neutrophils, which eat bacteria and other germs, and also lymphocytes, which release germ-disabling antibodies. 3 EPITHELIAL CELLS Tightly packed together, these cells provide a barrier to stop harmful chemicals and germs from reaching body 4 tissues. They cover the body, forming the outer layer of skin, and line hollow organs such as the stomach, lungs, and bladder. 4 BONE CELLS Osteocytes are bone cells that help keep the bone in good condition. At first, they lay down bone but later become stranded within a bony space. They keep in touch through tiny threads and pick up supplies from nearby blood vessels. 5 LIVER CELLS Also known as hepatocytes, liver cells enable the liver to perform many hundreds of roles to control blood composition and keep the body stable. These include processing and storing nutrients (foods) and removing poisons. 6 FAT CELLS As their name suggests, fat cells specialize in storing fat. They group A spherical together to form adipose tissue, fat cell is filled 6 mostly with which serves as an energy store, a droplet of cushions organs such as the kidneys, energy-rich fat and insulates the body under the skin. 63","64 1 SKELETON 1 SKULL Constructed from 206 bones, the human The bones in the skull protect the skeleton is a strong, flexible framework that brain, provide a framework for the supports and shapes the body and produces face, and anchor the muscles that movement when pulled by muscles. The skeleton also protects soft, internal organs, such produce facial expressions. The skull as the brain and lungs. Bones, which make up consists of 22 bones, 21 of which 20 percent of the body\u2019s mass, are connected are locked together by immovable to each other at joints and are held together by strong straps of tissue called ligaments. joints called sutures. Only the lower jaw (mandible) can move. Shoulder joint is the most Mandible moves to open 2 CHEST flexible joint the mouth for eating, breathing, and speaking The bones of the chest in the body 4 ELBOW (thorax) consist of the sternum 2 The bones of the upper arm (breastbone), the ribs, and part and forearm meet at the elbow. This joint acts like a door hinge of the backbone. Together, they allowing the arm to bend or straighten. The forearm bones form a protective \u201ccage\u201d that Humerus can rotate at the elbow, enabling the palm of the hand protects the lungs and the heart. to face upward or downward. 3 FOREARM 4 The forearm is made up of two parallel bones\u2014the ulna and Hip joint is the radius. The ulna curves where the around the humerus to form ball-shaped the elbow\u2019s point, while the head of the radius forms a joint with femur fits into the carpals (wrist bones). the cup-shaped Radius is the outer socket in the bone of the forearm hip bone Ulna is the inner bone of the forearm 3 Sacrum anchors the backbone to the pelvic girdle","Femur (thigh 5 6 7 bone) is the 6 PELVIS Phalanges are the longest bone in 14 slender bones the body This strong, bowl-shaped that form the structure consists of the fingers and thumb 5 KNEE two curved hip bones (pelvic girdle) and the 7 HAND The knee joint between the femur sacrum. The pelvis supports (thigh bone) and tibia (shin bone) the abdominal organs and Hinged at the wrist, the hand consists is the strongest and most complex attaches the thigh bones to of 27 bones and many movable joints joint in the body. This hinge joint the rest of the skeleton. (knuckles), which enable it to perform allows the leg to bend or straighten a wide range of tasks. The human and supports the body\u2019s weight during activities such as running, thumb is opposable, which means jumping, or kicking. that it can be rotated to touch the tips of each of the other fingers. Tibia (shin bone) forms joints with the femur Fibula is the and ankle bones smaller bone of the lower leg 8 FOOT Tarsals are the seven Each foot consists of the ankle, bones that form the sole, and toe bones, which support ankle, heel, and part and move the body\u2019s weight. These of the arch of the foot bones also provide a flexible platform that pushes the body off Metatarsals are the the ground during movement and five long bones that absorbs the shock on landing. connect the toes to the middle part of the foot 8 9 TOES Phalanges are the The phalanges of the toes are 14 slender bones much shorter and less flexible that form the toes than those of the fingers. The phalanges enable the body to stay upright and to stand on tiptoe. They also help to propel the body forward during movement. 9 65","MUSCLES Deltoid muscle raises arm sideways and swings it Every body movement\u2014whether backward and forward it\u2019s a leap in the air, a wink of the eye, a rumbling stomach, or a rapid heartbeat\u2014is produced by muscles. Skeletal muscles are attached to bones of the skeleton, which they pull to move us around. Smooth muscle moves food along the intestine. Cardiac muscle keeps the heart pumping. All muscles are made of cells called fibers that contract (get shorter) to produce a pulling force. 1 SKELETAL MUSCLE Rectus abdominis muscle Diaphragm muscle pulls in the abdominal separates the Long, cylindrical muscle fibers run wall and bends the in parallel and can reach up to 1 ft body forward thorax (chest) from (30 cm) in length. They are bundled Sartorius muscle bends the abdomen and together to form muscles that are the thigh at the hip aids breathing attached to bones by strong cords and turns it inward Adductor longus called tendons. Skeletal muscles muscle pulls and move the body when instructed Quadriceps femoris is a turns the thigh by the nervous system. group of four muscles inward that straightens the 2 SMOOTH MUSCLE leg at the knee Tightly packed into layered sheets, smooth muscle fibers are found in the walls of hollow organs, such as the small intestine, along which they push food, and the bladder, from which they expel urine. Smooth muscle contracts slowly and cannot be controlled voluntarily. 3 CARDIAC MUSCLE Tibialis DEEP MUSCLES anterior Found solely in the wall of the heart, muscle lifts FRONT MUSCLES cardiac muscle fibers form a branching the foot network that contracts automatically, Skeletal muscles are arranged in overlapping without stopping or tiring, to pump SURFACE MUSCLES layers, with surface muscles covering those blood around the body. Stimulation deeper down. Muscles at the front of the by the nervous system increases or body produce facial expressions, move the decreases heart rate according to head forward and to the side, move the the body\u2019s demands. arms forward and bend them at the elbow, bend the body forward and to the side, 66 bend the legs at the hip, straighten the knees, and lift the feet upward.","1 2 Triceps brachii Intercostal 3 straightens the muscles move arm at the elbow the ribs during Gluteus maximus Latissimus dorsi pulls breathing muscle straightens the arm backward and thigh at the hip when toward the body standing or climbing Gluteus medius muscle pulls thigh out to the side Biceps femoris Tibialis posterior muscle (one of turns the the \u201chamstrings\u201d) bends the leg at foot inward the knee Gastrocnemius muscle DEEP MUSCLES pulls the Achilles Peroneus longus tendon to bend the muscle arches foot downward foot when on tiptoe Achilles tendon is the thickest and strongest REAR MUSCLES tendon in the body All muscles are given Latin names that describe their size, location, shape, action, or other feature. Working downward from head to feet, skeletal muscles at the rear of the body keep the head upright, steady the shoulders, keep the back upright to maintain posture, pull the arms SURFACE MUSCLES backward and straighten them, straighten the thighs at the hip and bend the knees, and point the toes downward. 67","68 BODY SYSTEMS The body\u2019s trillions of cells are highly organized. Cells of the same The cerebellum is tucked \u25c0 BRAIN type are grouped together in tissues. Two or more types of tissue under the cerebrum and are used to build organs that perform specific roles. Organs form The brain is the center of different systems that each carry out an essential job, such as coordinates balance the nervous system, which digestion. There are 12 body systems that cooperate and interact and movement is responsible for controlling with each other to form the human body. The organs of six body activities. It is dominated body systems are shown here. The other six systems are the by the folded cerebrum that integumental (skin), skeletal (bones), muscular, endocrine enables us to feel, think, and (hormones), immune (defense), and reproductive systems. remember and instructs the body to move. Other brain parts Blood travels to and \u25c0 HEART are the cerebellum, tucked under from the heart via the cerebrum, and the brain stem, arteries and veins The cardiovascular which automatically controls system moves blood breathing and heart rate and LUNGS \u25bc around the body to links the brain to the spinal cord. deliver oxygen and The respiratory system food to all the body\u2019s \u25c0 SPINAL CORD consists of the two lungs and cells and to remove their wastes. Located An extension of the brain that the air passages that carry between the lungs, runs down the back, the spinal air from the outside. Each the heart is the center cord relays signals between brain lung contains a network of of this system\u2014a hollow, and body through the spinal branching tubes that end in muscular pump that nerves connected to it. It also millions of tiny air bags. It is contracts without tiring more controls many of the body\u2019s from these bags that oxygen than 70 times a minute to automatic reflex actions, such force the blood around the as pulling the hand back if it in the air passes into the body along blood vessels. touches something sharp. bloodstream. It is carried to Together the brain, spinal cord, and nerves form the all body cells where it is nervous system. used to release life-giving \u25c0 SPLEEN energy from food. The spleen is part Air travels Breathing of the lymphatic from the moves air system, the body\u2019s nose and in and out drainage network. mouth of the lungs It contains white along the blood cells, which trachea to the lungs fight infection by destroying bacteria, and also removes worn-out red blood cells from the blood.","Liver stores \u25b2 LIVER \u25c0 STOMACH excess glucose and releases The largest internal organ, the This muscular bag it when liver controls the composition expands as it receives the body of the blood, processing and stores food that has needs it nutrients newly absorbed been chewed and swallowed. from the small intestine. During storage, the stomach\u2019s PANCREAS \u25b6 walls churn food into a The gall part-digested \u201csoup,\u201d The pancreas bladder releases chemicals stores bile, which is released called enzymes into a fluid that into the small the small intestine aids fat intestine. to aid digestion, and digestion hormones (chemical The large messengers) into the Each kidney contains a intestine turns blood to control million tiny filtering waste into levels of glucose\u2014 units that process feces (poop) the body\u2019s main blood to make urine and pushes fuel\u2014in the blood. them out of the body The small intestine is a long tube in which most digestion and absorption occurs Ureter has muscular Billions of walls that squeeze harmless bacteria urine downward digest waste in to the bladder the large intestine URINARY Bladder is a DIGESTIVE SYSTEM \u25b6 SYSTEM \u25b6 muscular bag that, when filled, pushes The body needs nutrients for Consisting of the urine out through energy, growth, and repair. The kidneys, ureters, the urethra digestive system breaks down food bladder, and to release these essential nutrients. urethra, the urinary The system consists of the mouth system makes urine and teeth, the esophagus (a and removes it from the muscular tube leading from body. The kidneys make the mouth to the stomach), the urine by removing wastes stomach, and the small and large and excess water and salts intestines. Food is digested using from the blood, thereby keeping mechanical force, such as chewing, its composition constant. Urine and through chemical digesters is stored in the bladder called enzymes. Nutrients are and expelled through then absorbed into the blood the urethra at its base. and carried to the body\u2019s cells. 69","70 RESPIRATION The body\u2019s trillions of cells require an uninterrupted Twelve pairs of ribs supply of oxygen to release the energy they need to form the rib cage, which stay alive. They get this by means of a process called protects the lungs and respiration. Air containing oxygen is breathed into aids breathing the body by the respiratory system. Oxygen enters Muscles between the the bloodstream through the lungs and is carried to ribs move the rib cage, body cells. Waste carbon dioxide is carried by the which helps to pull air blood to the lungs and breathed out. into the lungs The trachea carries air to and from the lungs 1 RESPIRATORY SYSTEM Located in the head, neck, and chest, the respiratory system consists of the lungs, which fill most of the chest, and the air passages\u2014nasal cavity, throat, larynx, trachea, and bronchi\u2014that carry air. This X-ray shows the parts of the respiratory system located in the chest. The right bronchus branches from the trachea and divides repeatedly inside the right lung 2","Branches of 3 the smallest bronchioles reach the deepest parts of the lung 4 The diaphragm is a domed sheet of muscle that separates chest from abdomen 1 TRACHEA 2 BRONCHIAL TREE 3 BRONCHIOLES AND ALVEOLI 4 DIAPHRAGM Also called the windpipe, this flexible tube Once inside a lung, each bronchus divides The narrowest bronchioles end in 300 Situated just below the lungs, the diaphragm carries air between the larynx (voice box) at into smaller bronchi that then spilt even million air-filled bags called alveoli that fill plays a key role in breathing. When breathing the base of the throat and the two bronchi further. These, in turn, divide repeatedly to most of the lungs and are surrounded by in, the diaphragm contracts and flattens as that arise at its lower end. Up to 20 C-shaped form smaller branches called bronchioles. blood capillaries. Oxygen passes through the muscles pull the ribs upward and outward. rings of cartilage that encircle the trachea This arrangement is often called \u201cthe wall of each alveolus into the bloodstream This increases the space in the chest so that air hold it open during breathing in. Mucus bronchial tree\u201d because its structure looks in exchange for carbon dioxide, which is sucked into the lungs. When breathing out lining the trachea cleans the incoming air by like an upside-down tree with the trachea moves in the opposite direction. The alveoli the relaxed diaphragm is pushed upward, and as the trunk, bronchi as branches, and provide a large surface across which this the ribs move downward and inward, trapping dirt and germs, a process that bronchioles as twigs. exchange can take place efficiently. squeezing air from the lungs. began in the nasal cavity. 71","BLOOD Circulating around the bpBllloaosoomddaciseal5nls5d. p4e5rcpeenrtcent average body are 9 1wbcO6olhnonmieotteadidlilbrnciooelsonpl2los5po,d0lf3ac7bmte5elloi,lll0seol,i0todas0n.ndred Flowing all around your body, blood delivers pints (5 liters) of blood. food, oxygen, and other essentials to trillions Oxygen-rich blood in of cells and removes their wastes. Blood also arteries is bright red distributes heat around your body and defends in color. Oxygen-poor it against infection. Blood is made up of a yellow blood in veins is dark liquid called plasma in which blood cells float. purple-red. Red blood cells pick up oxygen in the lungs and deliver it to your body\u2019s cells. White blood cells defend the body against disease-causing germs. Blood also contains platelets, which enable it to clot to seal damaged blood vessels. The heart pumps blood around the body along three types of blood vessels. Arteries carry blood away from the heart, while veins return blood to the heart. Microscopic capillaries link arteries and veins and supply blood to cells. Plasma is 90 percent White blood cells Unraveled and Each as broad as a water and contains called neutrophils stretched out, one thumb, the largest more than 100 different and macrophages eat adult\u2019s blood vessels artery and vein (the dissolved substances, germs. Lymphocyte would encircle Earth aorta and vena cava) including food, waste, white blood cells twice. Capillaries would are 2,500 times wider hormones, and salts. disable germs by make up 98 percent of than a capillary, which releasing chemicals the total length. is just one-tenth the called antibodies. width of a hair. 72","Oxygen-carrying red During a lifes pan of Packed into every blood cells make up 99 120 days, a red blood red blood cell are 250 percent of all blood cells. cell travels around the million red-colored Every second, 2 million body 170,000 times\u2014 hemoglobin molecules. new red blood cells are once each minute. It Each one carries four made by jellylike red is then dismantled oxygen molecules, so marrow inside bones. and recycled by the a single red blood cell spleen and liver. can transport 1 billion oxygen molecules. The heart is made The heart beats, on Each person belongs largely of cardiac average, 70 times a to one of four blood muscle, which does minute. Heart rate groups\u2014A, B, AB, or not tire. can double or triple O. Blood groups are Over a lifetime of 70 during exercise to determined by tiny years, the heart beats get extra oxygen \u201cmarkers\u201d carried 2.5 billion times to your muscles. by red blood cells. without taking a rest. More than 112.5 million units of blood are donated around 73 the world every year. Blood transfusions replace blood lost during surgery and are used to treat some medical conditions.","SKIN, HAIR, AND NAILS Skin is the body\u2019s protective overcoat, forming a The epidermis consists of Flat, scaly cells in the barrier between vulnerable body tissues and the harsh, cells that migrate upward, upper epidermis are changing conditions of the outside world. It prevents dying, flattening, and filling constantly worn away water loss, blocks invasion by germs, repairs itself with keratin as they do so when damaged, helps us keep warm, and enables as skin flakes us to sense our surroundings. The uppermost layer of the skin is made from dead cells filled with a 1 tough, waterproof substance called keratin. Hair and nails, both derived from skin, are also made from dead, keratin-filled cells. 1 SKIN CROSS-SECTION The dermis contains Cells in the base of the living cells and fibers epidermis divide constantly A section through the skin reveals that that allow skin to to replace those lost it has two parts. The epidermis is a stretch and recoil from the surface germproof, waterproof barrier that protects against harmful rays in sunlight. 2 The thicker dermis contains blood vessels, sensory receptors, and sweat glands. Surface of the epidermis 2 SWEAT on the back of a person\u2019s hand This salty liquid is produced by sweat glands in the dermis. In hot conditions, sweat is released onto the skin\u2019s surface. It then evaporates, cooling the body Melanin, along and helping to maintain a constant with blood flowing body temperature of 98\u00b0F (37\u00b0C). through the dermis, gives the skin its color 3 SKIN COLOR Special cells in the epidermis 3 produce the brown pigment melanin, which filters out Skin surface is not Sweat is a watery harmful ultraviolet smooth but covered solution, filtered from rays from sunlight with ridges into which blood and containing before they sweat spreads salts and wastes, that can damage oozes from small skin cells. openings called pores 74","Fingernail is formed from layers of dead, flattened cells from the epidermis 4 Skin covering the fingertips is sensitive because it contains many touch receptors Hair shaft is made of dead cells packed with keratin, pushed up from the hair bulb 5 6 Hair follicle is 5 HAIR a hollow space in the skin Millions of hairs grow from the skin from which covering most body areas. Scalp hairs a hair grows protect the skin from sunlight and reduce heat loss. Finer, shorter body 4 FINGERNAIL hairs sense the presence of insects on the skin before they can sting or bite us. Ideal for gripping objects and scratching itches, fingernails are clear 6 TOUCH RECEPTORS plates that protect the sensitive The dermis contains a range of upper parts of the fingertips. receptors that respond to soft touch, The cells that make nails firmer pressure, and vibrations and die, flatten, and fill send signals to the brain so we can with keratin as feel our surroundings. The dermis they are pushed also has receptors that detect pain, forward from heat, and cold. the nail\u2019s root. 75 Sebaceous gland Hair bulb, deep secretes oily sebum in the dermis, that keeps hair and contains living, skin flexible and soft dividing hair cells","76 BRAIN Safely inside the skull, the brain allows us to sense, think, learn, remember, 1 PREFRONTAL CORTEX and move. It also automatically regulates vital functions such as breathing. The cerebrum, the main part of the brain, has two halves, or hemispheres. The most complex part of the cerebrum, the The left hemisphere controls the right side of the body and is in charge of prefrontal cortex makes us what we are. It language, math, and problem solving, while the right side controls the determines our personality and intellect and body\u2019s left side and deals with creativity, music, and art. The cerebrum\u2019s enables us to reason, plan, create, and learn many tasks are carried out by its outer layer, or cortex. This has distinct complex ideas and have a conscience. areas that have different roles. Motor areas trigger movement, sensory areas deal with the senses, while association areas interpret information. 2 BROCA\u2019S AREA Named after Paul Broca, the 19th-century doctor who discovered it, Broca\u2019s area is normally found in the left hemisphere. It plans what a person wants to say and sends instructions to muscles in the throat, tongue, and lips that produce speech. 3 6 5 4 1 2 11 10 8 7 12 9","3 PREMOTOR CORTEX 7 PRIMARY VISUAL CORTEX 10 WERNICKE\u2019S AREA Learned movement skills, such as playing When light hits the retina at the back of Usually located in the left hemisphere, tennis, are controlled and coordinated by each eye, its light detectors send signals to Wernicke\u2019s area gives meaning to words that the premotor cortex. It tells specific muscles the primary visual cortex. Here those signals have been heard or read. Named after the to contract either through the primary motor are interpreted as basic shapes, colors, and German doctor Karl Wernicke, it has a direct cortex or, in some cases, directly. movements before being passed on to the link to Broca\u2019s area enabling us to speak the visual association cortex. words we hear or see. 4 PRIMARY MOTOR CORTEX 8 VISUAL ASSOCIATION CORTEX 11 PRIMARY AUDITORY CORTEX Most movements we make are controlled by the primary motor cortex. Guided by This is where information from the primary When sounds are detected by the two ears, information from the cerebellum and other visual cortex about seen objects is interpreted they send signals to the primary auditory brain parts, it sends instructions to muscles and compared with previous visual cortex. Here the loudness, pitch (whether high that move the skeleton instructing them when, experiences. The visual association cortex or low), and rhythm of sounds are identified. and in what sequence, to contract. identifies what we are looking at and where it That information is passed on to the auditory is in space, enabling us to \u201csee\u201d it. association area. 5 PRIMARY SENSORY CORTEX 9 CEREBELLUM 12 AUDITORY ASSOCIATION AREA Receptors in the skin for touch, pressure, vibration, heat and cold, and pain send signals The cerebellum is responsible for producing Sounds are \u201cheard\u201d in the auditory association to the primary sensory cortex enabling us to smooth, coordinated movements of the body. area. Using information received from the feel those sensations. Our lips and fingertips It analyzes incoming information about the primary auditory cortex, it pieces together have high concentrations of receptors, hence body\u2019s current position and movement then the complete sound and, by comparing it their sensitivity. interacts with the primary motor cortex to with sounds stored in memory, identifies it precisely time muscle contractions. as, for example, music, speech, or thunder. 6 SENSORY ASSOCIATION CORTEX Basic information about touch, pressure, and other skin sensations is passed on by the primary sensory cortex to the sensory association cortex. Here sensations are analyzed, stored, and compared with previous experiences. It enables us to identify objects by touch. 77","SENSES 2 Our senses make us aware of the world around us Ear canal leads and the changes that are happening in it. The eyes to the inner ear detect light waves, and the ears sound waves, enabling where sounds us to see and hear. The tongue and nose detect dissolved are detected chemicals so we can taste, smell, and enjoy flavors. The skin allows us to feel the texture and warmth of objects. Spiky papilla enables the tongue to grip Iris controls the food but does not amount of light house taste buds entering the eye 1 Ear flap captures sound waves and funnels them into the ear canal Ringing the bell creates sound waves, which are detected by the ears Shapes, color, Hand bell and movement Smartphone are all detected by the sense of vision 1 VISION 2 HEARING Sweets taste sweet because they contain Vision is the most important sense, providing the brain The ears detect waves of pressure, called sound waves, lots of sugar with an immense amount of information about the body\u2019s that travel through the air. Sound waves are produced surroundings. Light reflected from, or produced by, outside by objects, such as a ringing cell phone or bell, which objects is automatically focused onto a layer of light receptors move or vibrate. The waves pass into the inner ear, that lines the back of the eye. In response, these receptors which is enclosed in bone on the side of the skull. send signals to areas at the back of the brain. From there, Here, receptors convert pressure waves into signals. we can determine what we are looking at and where it is, The signals travel to the brain, which identifies the thus enabling us to \u201csee\u201d moving, 3-D images in color. pitch, volume, and direction of the sound. 78","Taste buds Feathers feel 5 housed in soft and ticklish mushroom- shaped papilla 4 3 Skin ridges in the fingertips help us 3 TASTE grip the objects we touch Small projections on the A cactus spine tongue, called papillae, puncturing the house taste receptors skin stimulates called taste buds. Food a pain receptor molecules dissolved in Csaliva are detected by Some the taste buds. These can cheeses distinguish between five basic tastes\u2014sour, sweet, emit a salty, bitter, and umami strong (savory and meaty). In addition to helping us smell to enjoy food, our sense of taste enables us to detect foods that may be poisonous. itrus fruits Fresh flowers Lemons and most other 4 TOUCH 5 SMELL citrus fruits taste sour The skin acts like a sense organ. It contains several The nose can detect more than 10,000 different smells. different types of receptors that enable us to When air is breathed into the nose, odor molecules dissolve \u201cfeel\u201d our surroundings. Most are touch receptors in watery mucus and are detected by odor receptors high that send signals to the brain when the skin comes in the roof of the nasal cavity. Together, the senses of smell into contact with objects. Some detect light touch, and taste enable us to detect flavors. Smell is more important, some heavier pressure, and some vibrations. however, which explains why food lacks flavor when we Other receptors in the skin pick up temperature have a blocked nose. Some smells, such as those produced changes or detect pain. by burning, can warn us of danger. 79","REPRODUCTION Human beings have a limited life span but are able, Female egg through reproduction, to produce a new generation is large and to succeed them. Male and female reproductive systems spherical. It produce specialized sex cells\u2014called sperm and eggs\u2014that cannot move of unite during fertilization and combine their genetic instructions its own accord to make a new, unique human. After fertilization, the embryo\u2014 Male sperm later called a fetus\u2014grows and develops inside its mother\u2019s uterus with beating tail (womb) for the nine months of pregnancy. penetrates the outer layer of the egg FERTILIZATION \u25b2 Inside a woman\u2019s reproductive system, sperm swim toward and surround an egg and attempt to penetrate its outer layer. Eventually one succeeds, loses its tail, and its head fuses with the egg\u2019s nucleus, thereby combining two sets of genetic instructions (DNA). \u25c0 CELLS MULTIPLY As the fertilized egg, or pre-embryo, is swept toward the uterus, it divides repeatedly, producing first two cells, then four, then eight, and so on. Six days after fertilization, it embeds itself in the uterus lining. 72 hours after fertilization, The head becomes The liver makes the the pre-embryo is a more erect and the ears, embryo\u2019s blood cells ball of 16 cells including the organs of until bone marrow balance, develop can take over Dark retina of a developing eye on the side of the embryo\u2019s head \u25b2 FOUR WEEKS \u25b2 FIVE TO SIX WEEKS \u25b2 SEVEN WEEKS This pea-sized, four-week-old The embryo\u2019s brain continues to develop, as do other The bones of the grape-sized embryo\u2014its head is on the organs, such as the intestines. Its skull and face are taking embryo start to harden, and muscles left\u2014is growing in its mother\u2019s shape, and limbs, in the form of buds, are starting to grow. develop and get stronger. Wrists uterus. Its tiny heart is beating, The embryo floats within a sac filled with protective fluid. and ankles are now visible, and fingers and the nervous system and and toes are just starting to appear. vital organs are forming. Internally, the kidneys start to remove waste to make urine. 80","Placenta \u25b2 TEN WEEKS Eyes have \u25b2 TWENTY WEEKS moved from Now 500 times bigger than the side of Fingers and ears clearly visible, the a fertilized egg and consisting the head, movements of the fetus can be felt of billions of cells of different and eyelids by its mother inside her expanding types, the fetus, as it is now are forming uterus. The fetus blinks and swallows and follows phases of sleeping and called, has all its basic organs \u25b2 TWELVE WEEKS The fetus receives waking. The ridges that produce in place and is growing rapidly. food and oxygen fingerprints appear on its fingertips. through the umbilical Its large head accommodates Since their implantation, the cells cord, which is connected to the a fast-expanding brain. Fingers have been growing and specializing, mother via an organ called the placenta have formed, and fingernails and the tiny individual they have are growing. molded is now recognizably human. It has facial features, and fingers and toes have separated. The internal organs are in place, and the heart is beating. \u25b2 THIRTY WEEKS NEWBORN Ultrasound scanning, shown here, As pregnancy comes to an end, the uterus is a safe method used to monitor the contracts to push the fully grown fetus into the development of a fetus and can also bright, noisy outside world. The newborn baby reveal whether it is a girl or boy. At takes its first breath and the umbilical cord is cut. this stage, the brain is still growing In the next phases of its growth and development, rapidly. The fetus can hear sounds, the baby is completely dependent on its parents and its eyes respond to light. Its lungs for food, warmth, and protection. can now potentially breathe air. 81","GENETICS 1 Though all humans share the same basic body plan, each of us (aside from identical twins) has a unique mixture of features. That is because the set of instructions\u2014called genes\u2014required to construct a human varies slightly from person to person. Genetics is the study of how the genes we inherit from our parents shape the way we are. Eye color is controlled by specific genes, and different versions of those genes produce a range of colors 2 82","3 4 2 CHROMOSOMES A cell\u2019s DNA molecules are packaged into 23 pairs of chromosomes, which are found in the nucleus, the cell\u2019s control center. Normally, they are long and thin, but when a cell prepares to divide into two new cells, each chromosome shortens\u2014as its DNA coils up\u2014and duplicates, taking on the X shape shown here. 3 INHERITANCE We inherit half of our chromosomes from each of our parents. A set of 23 chromosomes contains about 25,000 genes. Maternal and paternal chromosomes carry matching pairs of each gene\u2014such as the gene that controls eye color\u2014but not necessarily the same version. If two versions are present, only one\u2014 1 DNA the dominant gene\u2014has an effect. Long molecules of DNA (deoxyribonucleic acid) are 4 GENETIC SIMILARITY found in every body cell. When magnified, DNA As brothers and sisters inherit a selection of genes resembles a twisted ladder with \u201crungs\u201d made from from the same two people, their parents, they four types of chemicals called bases (shown in color). are more likely to resemble each other than The sequence of bases along a section of DNA forms they would a nonrelative. Identical twins an instruction\u2014a gene\u2014for making one of the share almost identical genes, so they look proteins that build and run a cell. the same and are of the same sex. 83","84 NUTRITION Eating a balanced diet is an important part of good health. \u25c0 SUGARS The food we eat supplies the nutrients required to build and repair the body and to provide it with energy. Most of Foods such as sweets, cakes, and cookies our nutrition consists of three food types\u2014carbohydrates, should be eaten sparingly because they proteins, and fats\u2014but vitamins and minerals are also contain lots of added sugar. Eating large needed in tiny amounts. Water and dietary fiber are other key components. To remain healthy, a person should eat amounts of sugar gives the body a variety of food in the correct proportion. Carbohydrates, sudden bursts of energy rather than the body\u2019s main source of energy, come in two forms\u2014 the constant stream it obtains from complex carbohydrates and sweet-tasting sugars. complex carbohydrates. Sugar that is FATS AND OILS \u25b6 excess to requirements is stored as fat, causing a person to put on weight. Although fats and oils supply vitamins and are essential to the functioning of the body, Good-quality chocolate supplies some useful they should be consumed in moderation. nutrients but can also Plant oils, such as olive oil, contain be high in fat and sugar unsaturated fatty acids (as do oily fish), Walnuts are rich in which are good for health. However, omega-3 fatty acids, saturated fatty acids, contained in which are essential many animal foods and added to processed foods, can clog arteries. for good health Olive oil, like all unsaturated fats, is liquid at room temperature PROTEINS AND DAIRY FOODS \u25b6 About 15 percent of our diet should include proteins needed for growth and repair. Foods rich in proteins include nuts, beans, eggs, fish, and meat. Red meat is also rich in saturated fat, harmful to health if eaten in excess. Dairy foods, such as milk and cheese, supply the bone- building mineral calcium and some protein but can also be high in fats.","FRUIT AND VEGETABLES \u25b6 Orange, red, and green, Fruit is a good source of water, peppers are fiber, and vitamins and the natural all excellent sugars that give us a burst of sources of energy. Many also supply vitamins antioxidants, which can reduce A and C the risk of some diseases. Vegetables contain vitamins and minerals and are a good source of fiber. Nutritionists recommend that we eat at least five portions of fruit and vegetables daily. Brown rice is rich in some B vitamins Whole-grain bread supplies some iron, protein, and fiber Potatoes are a good source of both vitamins C and B6, as well as some minerals Bran cereals are rich \u25b2 COMPLEX CARBOHYDRATES in fiber, which helps make digestion Starch is the main complex carbohydrate in our diet. more efficient Foods rich in starch include pasta, cereals, potatoes, bread, and rice. During digestion, starch is broken Pasta is made from down to the sugar glucose, the body\u2019s main source wheat flour and is of energy. Complex carbohydrates should make a good source of up about half of our diet. slow-release energy 85","HEALTH DRUGS Co Blaurbeeesaupcdasoheutdesiesfbivttyhehceebayyatefanarrdelelariegsnaefssoyotodugh syrup A healthy body is one that is fit, strong, Chemicals that are used to treat and supple, and working well. Disease and injury prevent disease, by changing some prevent the normal working of the body. While aspect of the way the body works, are it is not always possible to avoid illness, the called drugs. Antibiotics, which kill harmful chances of developing a disease are reduced by bacteria, and analgesics, which reduce pain, adopting a healthy lifestyle, including getting are both examples of drugs. They may be regular exercise and eating a good, mixed diet of given to a patient in a number of ways\u2014 fresh foods. If a person does become ill, a doctor has to figure out exactly what the problem is and by injection, as pills and syrups that are then decide on a suitable course of treatment. swallowed, or as a vapor that is This might include drugs, surgery, or other inhaled into the lungs. means to return the person to full health. Inhaler is used to Hypodermic syringe is Laryngeal mirror is introduce drugs, used to inject drugs placed in the mouth such as those that to check the larynx treat asthma, into into the bloodstream, (voice box) the lungs skin, or a muscle Otoscope has a Pills lens and a light Thermometer and is used to look into a patient\u2019s ear Stethoscope is FIRST AID used to listen to Ophthalmoscope chest sounds The initial treatment to a enables a doctor to such as breathing person who is sick or injured examine the inside and heartbeat is called first aid. It is often carried out by someone who of a patient\u2019s eye is not medically qualified but has been trained to use simple DIAGNOSIS yet effective treatments. In more serious cases, first aid If a person is ill, his doctor first needs to may keep a person alive until determine exactly what is wrong with him. medical help arrives. A first-aid This is called making a diagnosis. The doctor kit contains essential items such asks about symptoms\u2014the features of the as disposable gloves, scissors, disease or injury the patient has noticed\u2014and antiseptic cream and wipes, considers the patient\u2019s medical history. Next, the doctor looks for signs to help identify the illness, adhesive bandages, for example, using a thermometer to check sterile dressings, body temperature. The patient may require and bandages. further tests, such as blood tests or X-rays. 86","Running shoes are Dumbbell weight ideal footwear for Chicken is a meat that running and other exercises that is rich in protein but improve fitness low in harmful fats PREVENTION Oranges, like all fruits, contain Regular exercise, such as running, walking, or playing vitamins that sports, improves fitness by making the heart and body muscles more efficient. It is also important to eat a are essential for balanced diet made up of a wide range of foods\u2014 good health Fish, especially oily fish, including pasta and rice, fruits and vegetables, lean contain fatty acids that can meat, and oily fish\u2014and low in salt, sugar, and reduce the risk of heart disease in the unhealthy fats found in red meat. Not only does a healthy diet reduce the risk of becoming overweight, but it can also help protect against certain diseases. Elasticated bandages SURGERY support joints, limit swelling, and secure Performed by a doctor called a surgeon, surgery dressings that involves cutting into a patient\u2019s body to repair, control bleeding remove, or replace tissue damaged by disease or injury. Surgery takes place in an operating room. To reduce the risk of infection, staff wear gowns and masks, and Stienr\u201csilttersouusoomrulgpsre\u201deegnoriucatnassteiltaodornebpstyehraeform everything is sterile (free of germs). During an operation, the patient is given an anesthetic\u2014a drug or gas that stops them from feeling any pain. Antiseptic cream Sterile dressing Coarse forceps Scalpel is a sharp Disposable gloves Fine scissorsblade for cutting through skin and Coarse scissorsother tissues ProbesFine forceps are used to grip and lift tissues during an operation 87","MOTHERBOARD This computer motherboard is a maze of microchips and other components linked by copper wires. It connects all the computer\u2019s components, passing on instructions and data with incredible speed. 88","Science and technology 89","The Orion Nebula, a ELEMENTS vast cloud of gas and dust, is made mainly of hydrogen Everything in the world is made from elements\u2014pure substances that cannot 1 be broken down into anything simpler. Elements can be grouped according to Magnesium is a silvery the properties they have in common, such substance that burns with as their appearance, how they conduct a dazzling white flame electricity, and how they react with other substances. There are nine main groups 2 and the element hydrogen, which is unique. Copper is a good conductor of heat and electricity 4 Potassium is an Radioactive sign alkali metal found is used to show in minerals in elements that Earth\u2019s crust emit radiation 3 5 1 HYDROGEN 2 ALKALINE-EARTH 3 ALKALI METALS 4 TRANSITION 5 ACTINIDES METALS METALS Hydrogen makes up 90 Sodium, contained in salt, The elements in this group percent of all the matter in Alkaline-earth metals react is an alkali metal. These This group is the largest are radioactive metals the universe. Pure hydrogen with water and are found elements are characterized and includes iron, silver, mostly created synthetically is an invisible gas on Earth. in minerals in Earth\u2019s by their vigorous reaction gold, nickel, platinum, and in nuclear reactors or It is not considered part of crust. In pure form, they with water. On contact, they titanium. Transition metals nuclear explosions. They any one group. Hydrogen are silvery-white. They are will zoom all over the water\u2019s are considered typical have unstable atoms that powers the nuclear reactions similar to alkali metals but surface or even explode. Alkali metals\u2014they are hard and break up and give out inside stars, including our less reactive. Calcium, found metals are not found in a pure shiny, conduct electricity radiation particles. Uranium sun, and is found on Earth in in chalk, milk, and bones, form in nature because they and heat well, and have and plutonium are examples the compound H2O, or water. is a member of this group. react so strongly with water. high melting points. of actinides. 90","6 8 Gadolinium, After hydrogen, like the other helium is the lanthanides, lightest element reacts easily and is used to with air fill balloons and airships because it is lighter than air The halogen Tin is often made bromine is a into alloys\u2014mixing red-brown it with copper makes liquid at room bronze, while temperature combining it with but evaporates lead forms pewter quickly to form a choking, 9 poisonous gas 10 7 Silicon is often used to make microchips for electronic devices 6 LANTHANIDES 7 NONMETALS 8 NOBLE GASES 9 POOR METALS 10 SEMIMETALS These soft, reactive metals Around one-sixth of elements There are seven noble gases\u2014 Metals that are fairly soft These elements have some were known as rare earths, are nonmetals. They are poor also called rare or inert gases and melt easily are known as properties of metals and because they were wrongly conductors of electricity and because they do not readily poor metals. They are readily some of nonmetals. Arsenic, believed to occur only melt at low temperatures. react with anything or found as ores (minerals) in for example, is shiny like scarcely in nature. Silvery- Carbon, nitrogen, and oxygen combine with other elements Earth and can be very useful, a metal but not a good white in appearance, they are all examples of nonmetals, to make compounds. They are especially when made into conductor. Some semimetals tarnish easily on contact with as are the halogens, a group of helium, neon, argon, krypton, alloys (two metals mixed are semiconductors, behaving air. Holmium, the element highly reactive elements that xenon, radon, and oganesson, together to make a harder as conductors or insulators with the greatest magnetic combine with other elements although the latter may be a metal). Aluminum and lead depending on what other strength, is in this group. to form salts. solid at room temperature. are both poor metals. substances are added to them. 91","MOLECULES Oxygen atom An element is a substance made of only one kind of atom. \u25c0 OXYGEN (O2) Atoms join, or bond, to other atoms of the same element or to atoms of other elements. They do this by sharing or Some elements can bond in exchanging electrons. In many cases, the bonded atoms form groups called molecules. When atoms of one several ways to form different element combine with atoms of other elements, substances. Atoms of the element they form compounds. oxygen (O) bond together in pairs to form molecules of oxygen gas. Hydrogen atom High in the atmosphere, however, oxygen atoms also bond in threes Oxygen atom to form the gas ozone. VITAMIN C (C6H8O6) \u25b6 Hydrogen atom Carbon atom Like ethanol, vitamin C (ascorbic acid) contains carbon (C), hydrogen (H), Carbon and oxygen (O) atoms. However, atom because the molecule contains different quantities of the elements arranged in a different way, it forms an entirely different substance\u2014a compound that is solid at room temperature. ETHANOL (C2H5OH) \u25b2 Hydrogen Oxygen atom atom Ethanol is a compound with molecules Carbon atom \u25c0 METHANE (CH4) containing two carbon (C) atoms, six hydrogen (H) atoms, and one oxygen Molecules of the gas methane contain (O) atom. At room temperature, it is a four hydrogen (H) atoms bonded to colorless liquid used as a disinfectant, a carbon (C) atom. Compounds of preservative, and the alcohol in drinks. carbon and hydrogen are called hydrocarbons. They include fuels, such as methane, oil, and coal, and artificial materials, such as polystyrene. Sodium and chlorine Chlorine atom atoms always join up in the same way to form cubic crystals Sodium atom \u25c0 SALT (NaCl) Table salt, or sodium chloride, is made of equal numbers of sodium (Na) and chlorine (Cl) atoms. Salt does not form as small individual molecules containing one atom each of sodium and chlorine. Instead, many atoms of the two elements link to form a rigid lattice called a crystal. 92","Oxygen atom \u25c0 WATER (H2O) SULFUR (S8) When two atoms of the gas Eight atoms of sulfur (S) hydrogen (H) bond with one atom bond together in a ring of the gas oxygen (O), they form to form a sulfur molecule. molecules of liquid water. Water is Most nonmetal elements the most common compound on are gases at room Earth and is essential for life. temperature, but sulfur is a brittle, yellow solid. Hydrogen atom \u25c0 DIAMOND (C) Sulfur atom A diamond can be thought of as a Nitrogen atom single giant molecule. It is formed from atoms of carbon (C) bonded in a strong Hydrogen atom \u25b2 AMMONIA (NH3) crystal lattice. However, if carbon atoms join in flat sheets of hexagonal tiles, The colorless gas ammonia is they form graphite, a brittle substance made up of one nitrogen (N) used to make pencil leads. atom bonded to three hydrogen (H) atoms. Plants get the nitrogen they need to grow from ammonia and other nitrogen compounds within the soil. Carbon atom Sticks are used to Except at the edges, show the bonds each atom is linked between atoms firmly to four others Balls represent atoms in models of molecules 93","ACIDS AND BASES \u25c0 CITRIC ACID An acid is a substance that produces positively charged The sharp taste in citrus fruit such as particles of hydrogen, called hydrogen ions, when lemons and grapefruit is due to the dissolved in water. The more hydrogen ions an acid citric acid they contain. Citric acid is contains, the stronger the acid is. A base is the chemical often artificially added to manufactured opposite of an acid. Bases produce negatively charged foods and drinks to give a tangy particles in water, called hydroxide ions. The sensation that tastes refreshing. more hydroxide ions a base contains, the stronger it is. Bases that dissolve in water Vinegar is made when are called alkalis. bacteria convert the ethanol in alcohol into acetic acid INDICATOR PAPER \u25bc \u25c0 VINEGAR When a strip of indicator paper is dipped into a liquid, the paper The sour taste of vinegar changes color. The color can be comes from the acetic acid it compared to a pH scale to find contains. Every step on the out the acidity of the solution. pH pH scale is 10 times less stands for \u201cpotential of hydrogen\u201d acidic than the previous and measures how many hydrogen step, so acetic acid with a pH ions the solution contains. of 4 is 1,000 times less acidic than hydrochloric acid. \u25c0 HYDROCHLORIC ACID The lower the pH value, the stronger the acid. Hydrochloric acid, created when hydrogen chloride gas dissolves in water, has a pH of about 1. It is highly corrosive, capable of eating through metals. \u25c0 STINGER \u25c0 CHEMICAL HAZARD When a bee stings, Strong acids and bases have it injects a mild acid to be stored in containers into a person\u2019s flesh, that will not be corroded which causes a stinging by the chemical within. These sensation. Washing the sting with alkaline soap containers are labeled with may relieve the pain by chemical hazard symbols that neutralizing the acid. show the potential dangers. 94","All bases tend to feel LIMESTONE \u25b6 slippery like soap Calcium carbonate, or LIQUID SOAP \u25b6 limestone, is a type of rock formed from the remains of Soap is a weak base. It is dead sea creatures over millions made by combining a of years. It is an important base, which is quarried and crushed weak acid with a strong base, making it only to make fertilizers, paints, ceramics, and cement. mildly alkaline with a pH of about 8. An indicator paper dipped into liquid soap turns blue. CLEANING FLUID \u25b6 The strongest bases have a pH of \u25c0 WATER 14 or more. Alkaline solutions with a high pH are used as cleaning Pure water is neither acid nor materials as they dissolve fats. alkali, but neutral, with a pH of 7. Cleaning fluids such as bleach and Rainwater is slightly acidic, with a pH caustic soda have a pH of around 10. of 5 to 6, while seawater is slightly alkaline, with a pH of between 8 and 9. The pH of tap water is usually between 6 and 8 depending on the gases and minerals that are dissolved in it HYDRANGEAS \u25b6 The hydrangea shrub produces different colored flowers depending on the acidity of the soil. On acid soils, it produces blue flowers, on alkaline soils, it produces pink or purple flowers, and on neutral soils, it has creamy white blooms. 95","Chalk and vinegar fizz CHEMICAL vigorously as the acid REACTIONS breaks down the chalk The atoms within a molecule are held together with 1 links called chemical bonds. In a chemical reaction, 2 the bonds between a molecule\u2019s atoms break, and the atoms bond in a different way to form new molecules. In some reactions, elements combine to 3 create a compound. In others, compounds break down into elements or simpler compounds. All the atoms from the original substance exist in the changed substance but in different places. Silver metal clings Burning is a nonreversible 6 to the copper coil reaction\u2014the wick cannot be remade from the ash and smoke The energy produced The explosion caused by When chemicals in an when sulfur and iron react igniting thermite produces apple\u2019s cells that contain causes the mixture to glow a temperature of around substances called phenols 4,350\u00b0F (2,400\u00b0C) are exposed to the air, they oxidize and turn brown 8 7 1 REACTION 2 DISPLACEMENT 3 BURNING 4 REACTION RATES 5 REVERSIBLE When vinegar (acetic acid) In a displacement reaction, When the wick of a candle The rate of a chemical A few reactions are reversible. and chalk (calcium carbonate) the metal that forms part of burns, it is reacting with reaction is affected by The molecules created by the are mixed, a chemical reaction a compound is removed and oxygen in the air to produce factors such as temperature, reaction can be reformed into takes place. The acidic vinegar replaced by another metal. ash and smoke. The burning pressure, light, surface area, the original materials. The breaks down the chalk to When a coil of copper is also produces energy in and concentration. It is initial reaction is called release carbon and oxygen dipped into a clear solution the form of heat and light. possible to change the rate the forward reaction, and as bubbles of carbon dioxide. of silver nitrate, the copper In all reactions, energy is of a reaction by varying one the reverse is the backward The starting materials in a displaces the silver from the used up when bonds of these factors. For example, reaction. Dinitrogen tetraoxide chemical reaction are called solution to form a blue between atoms break, and increasing the concentration breaks down into nitrogen reactants. The materials that solution of copper nitrate and energy is released as new of dye in a solution will dye dioxide when heated but exist after are called products. needles of solid metal silver. bonds are made. the material more quickly. reverts when cooled. 96","Concentrated dye At temperatures above At lower temperatures, contains more dye 284\u00b0F (140\u00b0C), nitrogen the nitrogen dioxide particles to collide dioxide exists as a molecules pair up to with the cloth brown gas make clear dinitrogen tetraoxide If heated again, brown nitrogen dioxide reforms 5 4 As crystals of potassium When a bread dough permanganate begin to mixture is left in a dissolve, purple trails warm place, carbon spread through the water, dioxide bubbles appear, until an even purple making the bread rise solution is formed 9 10 6 APPLYING HEAT 7 EXOTHERMIC 8 OXIDATION 9 SOLUTIONS 10 CATALYST When a mixture of yellow Thermite is a mixture of Some chemical reactions A solution is a mixture in A catalyst is a molecule that powder sulfur and silver- aluminum and iron oxide. happen around us naturally. which the molecules are helps bring about and speed gray iron filings is heated When it is ignited at a high One of the most common mixed so evenly and up a chemical reaction but to a high temperature, a temperature, there is an reactions is oxidation\u2014when completely that it seems like a does not change itself during chemical reaction takes explosion, as the chemical substances gain oxygen. single substance. However, in the reaction. Natural catalysts place, and iron sulfide is reaction produces a sudden Oxidation is happening when a solution, a chemical reaction are called enzymes. Bread formed. Without heat, the release of energy in the metals rust, when wood has not taken place. Neither dough rises because enzymes substances would not react form of light, heat, and burns, and when we breathe. the solute (the substance in yeast cause a reaction that with each other. Heat speeds noise. Reactions that In all these reactions, being dissolved) nor the produces bubbles of carbon up most reactions, and cold produce heat are known substances are reacting solvent (the substance that it dioxide when it is mixed with slows reactions down. as exothermic reactions. with oxygen from the air. is dissolved in) have changed. water and sugars. 97","98 STATES OF MATTER Everything you can smell, touch, or taste is made from matter, including living things such as yourself and nonliving things such as this book. Matter is made up of atoms, and anything that is not made of matter is energy. Heat, light, and sound are forms of energy. You cannot smell, touch, or taste energy, and it is not made from atoms. All matter on Earth exists in one of three states: solid, liquid, or gas. 1 1 SOLID Unlike most substances, 4 STATE TO STATE water expands when it A solid, such as this ice sculpture, freezes (instead of Matter changes from one state to has a fixed volume and a shape that contracting) because its another when it is heated or cooled. is not easy to change. Strong links molecules move farther Heating melts solids into liquids and hold atoms together and do not apart when locked into the boils liquids to form gases. Cooling allow them to move around, as they rigid structure of a solid condenses gases to form liquids and can in a liquid and in a gas. The freezes liquids into solids. As matter atoms in most solids are arranged changes from one state to another, 2 in regular patterns that form the atoms within it remain the same three-dimensional shapes, such as but become arranged differently. cubes and prisms, called crystals. 5 CHANGING SHAPE 2 GAS Solids do not always have a fixed shape. A gas does not have a fixed Some solids, such as ice or glass, are shape or a fixed volume. It brittle and will break if you hammer or expands to fill all the space crush them. Other solids, such as rubber around it. Atoms in a gas can or metals, are malleable and can be move freely in every direction. hammered, stretched, or squashed into They whizz around far too fast different shapes without breaking. to ever stick together. Most gases are invisible. Even steam cannot be seen until it condenses 5 into a mist of droplets as it mixes with cooler air 4"]