Skeletal System

Explore the amazing human Skeletal System! This worksheet teaches 3rd graders about bones, their purpose, and health tips.

Your Bonesby Cynthia SherwoodWithout your bones, you would be as floppy as a jellyfish. Our bones allow us to stand up straight. They support us and help us move, but they also protect our body's organs.Our skeleton is made up of all of our bones working together. If you have ever seen a real skeleton in a science class or museum, you might think that bones are dry and dead feeling. But that is not the case. Bones are made of living, growing cells. Inside most bones is soft marrow, which is where many of our blood cells are made. As a baby, you were born with nearly 300 bones. But adults only have about 206 bones because some of the smaller ones join together to form big ones.Certain bones are especially important. The skull inside your head acts like a helmet for your soft, squishy brain. Your skull helps protect you from injuries to your head. Your spine, or backbone, lets you stand up tall. Your spine also protects the spinal column with all of its nerves inside. Your ribs make a cage to protect your vital organs like the heart, lungs, and liver.Even though bones are very light, they are also very strong. That is why it usually takes a very bad fall or other serious accident to break a bone. If that does happen, you might wear a cast until new bone cells heal the break in a month or two.To protect your bones, wear a helmet whenever you ride your bike or skateboard. Knee pads, wrist guards, and other safety gear for sports are a good idea too. Strong bones need the mineral calcium, so drink lots of milk and eat dairy products. Bones also need active exercise, so go out and run, jump, and dance for healthy, strong bones. Why are dairy products good for your bones? True or False. Your bones are hollow. True False True or False. Blood cells are made inside your bones. True False True of False. Adults have more bones than babies do. True False Bones Purpose Click the box on the right to select the correct description of what each bone protects. Use the information given in the text. Bone(s) What they protect RIBS Protects your lungs and heart SPINE Helps you stand up tall and protects the nerves in your spinal column SKULL Protects your brain Use your math skills!How many MORE bones do babies have than adults? 206 300 94 506