The human skeleton is the internal framework of the body.
It is composed of around 300 bones at birth – this total decreases to 206 bones by adulthood after some bones have fused together.
The bone mass in the skeleton reaches maximum density around age 20.
The human skeleton can be divided into the axial skeleton and the appendicular skeleton.
The axial skeleton is formed by the vertebral column, the rib cage, the skull and other associated bones.
The appendicular skeleton, which is attached to the axial skeleton, is formed by the shoulder girdle, the pelvic girdle and the bones of the upper and lower limbs.
It is composed of around 300 bones at birth – this total decreases to 206 bones by adulthood after some bones have fused together.
The bone mass in the skeleton reaches maximum density around age 20.
The human skeleton can be divided into the axial skeleton and the appendicular skeleton.
The axial skeleton is formed by the vertebral column, the rib cage, the skull and other associated bones.
The appendicular skeleton, which is attached to the axial skeleton, is formed by the shoulder girdle, the pelvic girdle and the bones of the upper and lower limbs.
The human skeleton performs six major functions;
1:Support,
2: Movement,
3:Protection,
4:Production of blood cells,
5:Storage of minerals,
6:Endocrine regulation.
1:Support,
2: Movement,
3:Protection,
4:Production of blood cells,
5:Storage of minerals,
6:Endocrine regulation.
The human skeleton is not as sexually dimorphic as that of many other primate species, but subtle differences between sexes in the morphology of the skull,dentition, long bones, and pelvis exist.
In general, female skeletal elements tend to be smaller and less robust than corresponding male elements within a given population. The human female pelvis is also different from that of males in order to facilitate child birth.
Unlike most primates, human males do not havepenile bones.
In general, female skeletal elements tend to be smaller and less robust than corresponding male elements within a given population. The human female pelvis is also different from that of males in order to facilitate child birth.
Unlike most primates, human males do not havepenile bones.
Divisions
Axial skeleton
Main article: Axial skeleton
The axial skeleton (80 bones) is formed by the vertebral column (32–34 bones; the number of the vertebrae differs from human to human as the lower 2 parts, sacral and coccygeal bone may vary in length), a part of the rib cage (12 pairs ofribs and the sternum), and the skull (22 bones and 7 associated bones).
The upright posture of humans is maintained by the axial skeleton, which transmits the weight from the head, the trunk, and the upper extremities down to the lower extremities at the hip joints. The bones of the spine are supported by many ligaments. The erector spinae muscles are also supporting and are useful for balance.
Appendicular skeleton
Main article: Appendicular skeleton
The appendicular skeleton (126 bones) is formed by the pectoral girdles, the upper limbs, the pelvic girdle or pelvis, and the lower limbs. Their functions are to make locomotion possible and to protect the major organs of digestion, excretion and reproduction.
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