How many sesamoid bones are there in the human body?

• A. Three
• B. Two
• C. One
• D. Four

Answer: (B)

Sesamoid bones are small bones embedded within tendons, and they help increase leverage and protect tendons as they cross joints. The most obvious and consistently present sesamoids in the body are the kneecaps, one in each knee. That gives a total of two sesamoid bones that are reliably present in most people.

There are also other smaller sesamoids that can occur in various parts of the body (like in the wrists or under the big toe), but these are not always present in everyone. So, the typical, consistently present count is two.