Fifth Grade
Worksheets
Take a Tour of the Skeletal System, Part 2
The skeletal system is the name of the bones in your body. Your skeleton gives your body shape. It holds you up. It protects your soft organs like your heart and lungs. It works with muscles to help you move. Your bones are alive, just like the rest of your body. They grow and change as you grow.
When you were born, you had about 300 bones. An adult only has 206 bones. That's because many of the bones fuse or grow together as people grow up. Many baby bones are made of cartilage. Cartilage is like the end of your nose. It is tough and flexible. As babies grow, the cartilage turns into hard bone. It needs lots of calcium to do this. That's why it is important for kids to drink lots of milk. You can get calcium from yogurt, ice cream, and cheese, too.
At your shoulder, bones called the clavicle and the scapula form a socket. The bone from the top of your arm, called the humerus, is a ball joint that fits into this socket. This ball and socket joint rotates so that you can turn your arm in any direction.
Put your fingers on the front of your neck. Move your fingers down your chest. The first bones you feel just below your neck are the clavicles. The common name is collar bones. Below these, you can feel your ribs. You have twelve ribs on each side (twelve pairs) or 24 ribs. They curve around your heart and lungs to protect them. You can feel your ribs move when you breathe.
