Your ribs are part of your torso. You have 12 pairs of flat bones creating your ribs. Your ribs are used to protect your lungs and heart. Muscles are attached to your ribs when you inhale (Breath in). These muscles contract when you inhale. When you inhale these muscles contract to list your ribcage so your lungs can expand. When you exhale your ribcage muscles relax. When the air leaves your lungs, your ribcage gets smaller.