Think about how many movements you perform every day, from the time you wake up to the time you go to sleep again.
You get out of bed, brush your teeth, take breakfast foods to your mouth, chew, go to school, come back, do gymnastics, run, use your hands to hold something, stroll, sneeze, yawn, push and pull objects, practice dance steps while listening to music, play basketball, practice any other sport…
The adult human skeleton consists of about 200 bones. The skeleton supports the body, protects various organs and is associated with many of the movements we perform. Human beings and other vertebrate animals move in the most diverse ways and for the most diverse purposes.
The bone skeleton, besides body support, has three important functions:
- Reserves of mineral salts, especially calcium and phosphorus, which are fundamental to the functioning of cells and must be present in the blood. When the calcium level decreases in the blood, calcium salts are mobilized from the bones to supply the deficiency.
- Certain bones still have yellow marrow (or marrow). This marrow consists mainly of fat cells, which accumulate fat as a reserve material.
- Inside some bones (such as the skull, spine, pelvis, sternum, ribs, and the heads of the arm and thigh bones), there are cavities filled with soft tissue, the red bone marrow, where blood cells are produced: red blood cells. , leukocytes and platelets.
There is a cartilaginous skeleton during embryonic life, which will be almost entirely replaced by a bone skeleton. This is what is called endochondral ossification (from Greek endos, In and chondros, cartilage).
Bones begin to form from the second month of intrauterine life. At birth, the child already has a very ossified skeleton, but the ends of several bones still maintain cartilage regions that allow growth. Between the ages of 18 and 20, these cartilage regions ossify and growth ceases. In adults, there is cartilage where flexibility is important (at the tip of the nose, ear, larynx, tracheal wall, and articulating bone ends).