Discovered by second-century physician Claudius Galenus, sesamoid bones are bony protrusions or nodules that develop in tendons and are attached to ligaments. These strategically located bones are taken for granted, but they are essential for creating stable environments so the body can carry out specific tasks. Sesamoids act like biological pulleys, allowing muscles to flex and extend in different directions and angles. They also bear the body’s weight more efficiently.


1. Lenticular Process of the Incus

In the 17th century, anatomists discovered a knob-like projection at the end of the incus bone in the ear. They called it the lenticular process of the incus. For more than a century, scientists debated whether the lenticular process is a separate bone, but studies show it is connected to the incus by a bony stub called a pedicle. What makes this projection a sesamoid bone is that it is a part of a chain of bones that acts as an acoustic vibration lever; the lenticular process is the short arm of the lever.

ear incus ttsz / Getty Images

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