The Skeletal System
From your teeth to your toes, your bones give your body structure and a frame to which your muscles can attach in order to hold you upright. Bones fulfill many purposes beyond helping you grasp an item and walk; they also serve as your body’s “armor.” Your skull protects your brain, your rib cage shields your heart and lungs, and your bone marrow manufactures your immune system’s white blood cells to fight off unwelcome bacteria and viruses. Red blood cells are also made in your bone marrow, carrying life-giving oxygen throughout your body.
Your body separates your bones with joints and cartilage so they do not rub against each other, while connective tissues hold it all together. All of these components make up your amazing skeletal system, defining your features while shielding you from bumps, bruises and microscopic invaders.