Through engaging text, readers learn about the human body's skeletal system, which is made up of all the bones in the body. The book explains that bones hold you up, protect delicate organs such as your heart, help you move, and store fat, phosphorus, and calcium. Readers discover that ligaments and tendons hold bones together, a joint is where two bones meet, and bone marrow makes red blood cells, which carry oxygen throughout your body, and white blood cells, which help fight germs. Kid-friendly text explains the axial skeleton, which includes the skull, the spine, the breastbone, and ribs, and the appendicular skeleton, which includes all the bones that branch off the axial skeleton, including arms, hands, legs, and feet. Readers learn that babies are born with 300 bones, some of which are made of cartilage. The hardening and fusing of bones as babies grow is discussed. Also highlighted are bone fractures and how they heal; diseases that affect the skeletal system, such as arthritis and osteoporosis; and how to care for the skeletal system with a healthy diet, plenty of calcium, and lots of exercise. Full-color photos, detailed diagrams, medical models, phonetics, glossary, and index enhance the text.