List of bones of the human skeleton
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The skeleton of an adult human consists of 206 bones. It is composed of 270 bones at birth, which decreases to 206 bones by adulthood after some bones have fused together. 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.
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.
- The spinal vertebrae of the vertebral column (26 bones)
- The sternum (1)
- The ribs (24, in 12 pairs), including:
- (7) pairs called "true ribs" directly attached to the sternum (1st-7th pairs)
- (3) pairs (8th,9th and 10th pairs), also known as false ribs are attached anteriorly to each other and to the 7th rib by cartilages and synovial joints
- (2) pairs of floating ribs (11th and 12th pairs), have no anterior attachment.
- The skull (1)
- The cranial bones (8)
- The facial bones (15)
- In the middle ears (3 x 2=6)
- The bones of the upper arm (6 bones, 3 each side)
- The hand (54 bones, 27 in each hand)
- The hip bone, comprising the fused ilium, ischium, and pubis (2)
- The sacrum and the coccyx attach to the two hip bones to form the pelvis
- The femur
- The patella or knee cap
- The tibia
- The fibula
- The foot (52 bones in total, 26 per foot)
- The tarsus
- The metatarsals
- The phalanges of the foot