List of bones of the human skeleton

The skeleton of an adult human consists of 206 bones. It is composed of 237 bones birth, which decreases to 206 bones by adulthood after some bones have fused together.[1] It consists of 80 bones in the axial skeleton (28 in skull and 52 in torso) and 126 bones in the appendicular skeleton (32 x 2 in upper extremities including both arms and 31 x 2 in lower extremities including both legs). Many small and often variable bones, such as some sesamoid bones, are not included in this count.

Introduction

The figure of 206 bones is commonly repeated, but does have some peculiarities in its method of counting. It is taken of an adult human—the number of bones in the skeleton changes with age, as multiple bones fuse,and a process which typically reaches completion in the third decade of life. In addition, the bones of the skull and face are counted as separate bones, despite being fused naturally. Some reliable sesamoid bones such as the pisiform are counted, while others, such as the hallux sesamoids, are not.

Individuals may have more or fewer bones than this owing to anatomical variations. The most common variations include additional (i.e. supernumerary) cervical ribs or lumbar vertebrae. Sesamoid bone counts also may vary among individuals.

Bones

Vertebral column

Chest

Skull

Arm

Leg

The sesamoid bones

See also

References

  1. Mammal anatomy : an illustrated guide. New York: Marshall Cavendish. 2010. p. 129. ISBN 9780761478829.
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