Sesamoid bones are small bones in tendons where considerable pressure develops, for instance, in the wrist. These, like sutural bones, are also variable in number. Two sesamoid bones, the patellas (kneecaps) are present in all individuals.

籽骨是肌腱中的小型骨，肌腱中会产生相当大的压力，例如在腕部。这些骨像缝间骨一样，在数量上是可变的。两块籽骨——髌骨（膝盖骨）存在于所有个体中。