T


ouch the back of your neck. Do you


feel the bones in your neck? You have seven neck bones. Which do you think has more neck bones—you, a mouse, or a giraffe? Surprise! The giraffe and mouse have seven, too. Its neck is longer because its bones are bigger. Neck bones are part of your body’s skeleton. The skeleton gives your body strength and support. You would just flop around without it.


Bones also protect you. They protect your heart, your lungs, and many other organs. Bones do one more thing. They help your body move.


Bone Basics Bones are living things. T ey grow and change as you grow. As a baby, your skull had 22 bones. As you grow, these bones grow together. T ey form a shell around the brain. T e skull protects your brain and your eyes. Not all skulls are alike. Take an


elephant’s skull, for example. It is large and thick. It holds up the elephant’s heavy trunk and tusks. A tarsier’s skull is small and thin. It has large spaces to hold the animal’s big eyes.


Lending Support A backbone protects and supports your body. Your backbone is made up of lots of small bones. T ese bones are all linked together.


T ey’re called vertebrae. T at’s why animals with backbones are called vertebrates. Together, vertebrae make a long


tunnel. Your spinal cord runs through this tunnel. Your spinal cord is kept safe while it sends messages to and from your brain. Ribs support and protect you, too.


giraffes 4


T ey are flat and curved. Ribs form a cage in your chest. Your heart, lungs, and some other organs nestle inside.


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