Your ribcage is the bony, basket-like structure in your chest made up of your ribs, breastbone, and spine. If you press your hands against the sides of your chest and take a deep breath, you can feel your ribcage expand outward. The ribcage works like nature's armor, protecting vital organs inside, like your heart and lungs.

You usually have 24 ribs in total, twelve on each side, all attached to your spine in back. The top seven pairs connect directly to your breastbone in front, the next three pairs connect to the breastbone through cartilage, and the bottom two pairs are called “floating ribs” because they don't attach in front at all. The ribcage is strong enough to shield your organs from impacts, yet flexible enough to move when you breathe. Each time you inhale, muscles lift your ribcage up and out, creating space for your lungs to fill with air.

Animals have ribcages too: birds have lighter, more delicate ones for flight, while whales have massive ribcages to protect their lungs during deep dives.