The human skeleton consists of 204 bone disorders in adulthood borne and supported by ligaments, tendons, muscles, fascia and cartilage. The body is composed of 2 sesamoid bones but not forming part of the human skeleton by definition.
The skeletal changes with age as the development of bone structure. The fetus does not have any solid skeleton, it will form gradually during nine months of gestation. At birth, a baby has more bones than it will in adulthood (approximately 270). The difference comes from the subsequent merger of small bones in the skull, spine and pelvis.
The role of the skeleton is twofold. It is both the timber body, which muscles and other structures will be set and it also provides a protective function in certain organs, such as those located in the thoracic cavity (heart, lungs ...) or brain protected by the bones of the skull.
The longest bone in the body is the femur. The smallest is the stirrup, which is located in the middle ear.
Most organs are outside the skeleton except the brain which is located inside the skeleton.
Role of the bone
* It provides a framework for the body and protects organs by large cavities that form (head, thorax, pelvis).
* It is the basis of the mobility of the body by joints that allow muscles to operate the different segments of the skeleton.
* There is a large reserve of minerals, especially calcium and phosphorus.
* It allows the production of blood cells in bone marrow.
Variation in the enumeration of the skeleton
Everyone does not count the same way the number of bones of human skeleton, ie the number of constant bone of a human being in adulthood: it is mostly d a question of definition of their joints. The articulation of the bones will influence their parity (eg the frontal bone and mandible odd that become peers in adulthood), their number, with fusion of bones (sternebrae which become the body of the sternum and sacrebes that become the sacrum), mobility (although the manubrium be confused with the sternum) or character as the sesamoid patella (kneecap) or the sesamoid bones of the thumb.
The main difference count is around the patella, sacrum and coccyx. Should we count the patella, this important bone sesamoid bones as a skeleton? Do we have 26, 30 or 33 vertebrae (respectively with sacrum and coccyx, sacral vertebrae and coccyx and sacral and coccygeal vertebrae)? We have 33 vertebrae in average (sometimes 34 depending on the tailbone), but we do not all have when we count our skeleton.
Ansi can count at least 204 bones (without patella, with the sacrum and coccyx) and a maximum of 224 bones (vertebrae, 5 sacral, 4 coccygeal vertebrae, the manubrium, the fabella the two sesamoid bones of the thumb sesamoid bone index and both sesamoids of the hallux). One could also consider the mandible even (as the hip bone and like the jaw) and the frontal bone as a peer, at 226 bones or, conversely, the bones of the skull and face bones as one whole as the manubrium and body of the sternum (21 bones sutured) a minimum of 184 bones. However, the sutures of the calvaria are not the same as that of the two parts of the frontal bone, coccygeal vertebrae fused vestigial remain opposed to sacral vertebrae fused ... Try to consider how the bones are interrelated: the mobility of their joints.
The highest number known is 206 (including the patella, the sacrum and coccyx or 26 vertebrae), taught in 2008 at the Faculty of Medicine Pitie-Salpetriere University of Pierre and Marie Curie. It is simply the number of articulated bones constant of the human adult.
A second is 208 (including 5 sacral vertebrae and coccyx or 30 vertebrae), appeared most recently in the literature.
A third, less common is 204 (including the sacrum and coccyx, and did not spot the patella as a skeletal bones), taught in 2003 at the Faculty of Medicine Necker, University Paris Decartes.
All these numbers are correct and describe the same average adult human skeleton, simply explain what they intend (skeletal bones, bone independent bone sutured, ...) and when (a newborn has more bones that an adult and a person aged less with osteoarthritis).
Read also Osteoporosis