How to use the explorer
Tap or click any part of the skeleton, or press Tab to move between regions with a keyboard and Enter to open one. The panel shows how many bones that region holds, what each one does and a fact worth remembering. Type a common name such as collarbone, tailbone or kneecap in the search box and the explorer finds the anatomical name for you.
Counts are for both sides of the body together. The hands, for example, show 54 bones: 27 in each wrist and hand.
How the 206 bones break down
Anatomists split the skeleton into two parts. The axial skeleton (80 bones) runs down the body's center line: the skull, the six tiny ear bones, the hyoid in the throat, the spine and the rib cage. The appendicular skeleton (126 bones) is everything that hangs off it: the shoulder girdles, arms and hands, pelvis, legs and feet.
| Region | Bones |
|---|---|
| Skull (8 cranial, 14 facial) | 22 |
| Middle ear ossicles | 6 |
| Hyoid | 1 |
| Spine (24 vertebrae, sacrum, coccyx) | 26 |
| Sternum and ribs | 25 |
| Shoulder girdles | 4 |
| Arms, wrists and hands | 60 |
| Hip bones | 2 |
| Legs, ankles and feet | 60 |
| Total | 206 |
Five bone shapes
Bones are also grouped by shape, which hints at their job:
- Long bones such as the femur and humerus are longer than they are wide and act as levers for movement.
- Short bones such as the wrist's carpals and the ankle's tarsals are roughly cube-shaped and give stability with a little gliding movement.
- Flat bones such as the skull plates, ribs and shoulder blades protect organs and give muscles broad surfaces to attach to.
- Irregular bones such as the vertebrae and many facial bones have complex shapes that don't fit the other groups.
- Sesamoid bones such as the kneecap and pisiform sit inside tendons, protecting them and improving leverage.
Bones are living tissue
Bone constantly breaks down and rebuilds itself in a process called remodeling. That's why bones heal after a fracture, why they grow stronger when you load them with exercise, and why they can thin with age, inactivity or conditions such as osteoporosis. Our osteoporosis guide and bone-strengthening exercise guide explain how to keep the remodeling balance in your favor.
Where do your bones stand?
Take the two-minute bone health risk check. It's private, needs no sign-up, and ends with questions to bring to your next appointment.