The bones
The smallest bone in the human body is the stapes, a stirrup-shaped bone in the middle ear. It sits beside the malleus and incus, whose names mean hammer and anvil, and the three pass vibrations from the eardrum toward the inner ear.
There is one set in each ear, so the body has six auditory ossicles altogether. They are easy to lose in the usual head count because the adult skull has 22 bones, while the ossicles and hyoid are seven additional bones associated with the head. Add those seven and the wider head count becomes 29. The Bone Room keeps the ear bones on this page, but they still belong to the 80 bones of the axial skeleton and count toward the same 206.
Their names make a pleasing little chain. The handle of the malleus attaches to the eardrum, its head meets the incus, and the incus meets the stapes. The footplate of that final, tiny stirrup presses at the oval window of the inner ear. All three begin turning to bone before birth, although the often repeated claim that they are already full adult size at birth is more than the sources used here establish.
These 3 entries account for 6 of the 206.How the 206 is counted.
On this page: Try one · Questions · The specimens · Nearby
01 · Try one
This is how the lab asks. A bone you name today comes back a week later to be named again, and that is how it stays known.
First of the three tiny middle-ear bones: its handle is fixed to the eardrum and passes vibration along the chain.
2 (one per ear)
The middle link of the three ear bones, taking vibration from the first and handing it to the last.
2 (one per ear)
Last of the three ear bones; its oval footplate presses against the doorway of the inner ear.
2 (one per ear)
02 · Questions
The stapes. It is the third bone in the middle ear's chain of ossicles and has a head, two legs, and a footplate, giving it the shape of a stirrup. StatPearls, Ear Ossicles
They carry vibration across the middle ear. The malleus moves with the eardrum, the incus passes that movement along, and the stapes presses against the oval window to move fluid in the inner ear. OpenStax, Sensory Perception
Malleus, incus, and stapes are Latin names that roughly translate to hammer, anvil, and stirrup. Each name describes the bone's shape. OpenStax, Sensory Perception
03 · The specimens
04 · Learn them
In the lab these are Case 09, The Auditory Ossicles, on the Scholar track, which opens once the Explorer case files are done. The lab starts with the big bones, so the ear comes later.
It introduces bones a few at a time, asks where they are, and comes back days later to check they stayed.
Start with the big bonesBegin with four bones. It’s free, and you don’t need an account.
Nearby: arm and shoulder · leg · rib cage · spine and pelvis · hand · wrist · foot and ankle · skull · all nine