Medical Definition of Skeleton, bones of the (2024)

Skeleton, bones of the: The human body has 206 bones. These consist of 80 axial (head and trunk) bones and 126 appendicular (upper and lower extremity) bones.

Axial bones: The 80 axial bones comprise 29 bones in the head and 51 bones in the trunk.

Head bones: The 29 head bones consist of 8 cranial bones, 14 facial bones, the hyoid bone, and 6 auditory (ear) bones.

• The 8 cranial bones are the frontal, 2 parietal, occipital, 2 temporal, sphenoid, and ethmoid bones.
• The 14 facial bones are the 2 maxilla, mandible, 2 zygoma, 2 lacrimal, 2 nasal, 2 turbinate, vomer and 2 palate bones.
• The hyoid bone is horseshoe-shaped bone at the base of the tongue.
• The 6 auditory ossicles (little bones) are the malleus, incus and stapes in each ear.

Trunk bones: The 51 trunk bones consist of 26 vertebrae, 24 ribs and the sternum.

• The 26 vertebrae comprise 7 cervical, 12 thoracic and 5 lumbar vertebrae, the sacrum and the coccyx.
• The 24 ribs comprise 14 true ribs, 6 false ribs and 4 floating ribs.
• The sternum is the breast bone.

Appendicular bones: The 126 appendicular bones are made up of 64 bones in the upper extremities (the arms, wrists, and hands) and 62 bones in the lower extremities (the legs, ankles, and feet).

Upper extremity bones: The 64 upper extremity bones consist of 10 shoulder and arm, 16 wrist and 38 hand bones.

• The 10 shoulder and arm bones are the clavicle, scapula, humerus, radius, and ulna on each side.
• The 16 wrist bones are the scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate on each side.
• The 38 hand bones are the 10 metacarpal bones and 28 phalanges (finger bones).

Lower extremity bones: The 62 lower extremity bones consist of 10 hip and leg, 14 ankle and 38 foot bones.

• The 10 hip and leg bones are the innominate or hip bone (fusion of the ilium, ischium, and pubis), femur, tibia, fibula, and patella (kneecap) on each side.
• The 14 ankle bones are the talus, calcaneus (heel bone), navicular, cuboid, internal cuneiform, middle cuneiform, and external cuneiform on each side.
• The 38 foot bones are the 10 metatarsals and 28 phalanges (toe bones).