Village Life

Human skeleton
From Wikipedia, the free encyclopedia

Anterior view of an adult human skeleton

Posterior view of an adult human skeleton
The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, muscles and cartilage. It serves as a scaffold which supports organs, anchors muscles, and protects organs such as the brain, lungs and heart.[citation needed]
The biggest bone in the body is the femur in the thigh and the smallest is the stapes bone in the middle ear. Several factors contribute to the bone density and average mass of the human skeleton including; gender, race, hormonal factors, nutrition, physical activity and lifestyle behaviors.[1] Because of these and other factors affecting an individual's weight the human skeleton may comprise between 12 and 20 percent of a person's total body weight with the average being 15 percent.[2]
Fused bones include those of the pelvis and the cranium. Not all bones are interconnected directly: there are three bones in each middle ear called the ossicles that articulate only with each other. The hyoid bone, which is located in the neck and serves as the point of attachment for the tongue, does not articulate with any other bones in the body, being supported by muscles and ligaments.
Contents [hide]    * 1 Development   * 2 Organization       * 2.1 Axial skeleton       * 2.2 Appendicular skeleton       * 2.3 Support       * 2.4 Movement       * 2.5 Protection       * 2.6 Blood cell production       * 2.7 Storage       * 2.8 Endocrine regulation   * 3 Sex-based differences   * 4 Disorders       * 4.1 Osteoporosis   * 5 References |
[edit] Development
Early in gestation, a fetus has a cartilaginous skeleton from which the long bones and most other bones gradually form throughout the remaining gestation period and for years after birth in a process called endochondral ossification. The flat bones of the skull and the clavicles are formed from connective tissue in a...