Skeletal system

We are born with 270 bones in our bodies, and even more bones form during childhood. By the time we reach adulthood though, several separate bones have fused together so that the number of our bones has decreased to around 206, which make up the adult skeletal system. An example of this reduction occurs in each half of our pelvis, where three separate bones the ilium, the ischium, and the pubis fuse into one single bone called the os coxa. 

The skeletal system is further divided into the axial skeleton, consisting of the bones of the skull, vertebral column, and the thoracic cage; and the appendicular skeleton, which consists of the bones of the upper and lower extremities along with their associated girdles as below table.

Around 206 some people develop varying numbers of miscellaneous bones, either sesamoid bones, which form within some tendons as a response to stress (such as the patella) or sutural bones, which develop within the sutures of the skull.

Summary of the Bones of the Adult Skeletal System

Our skeleton consists of all our bones, teeth, cartilage, and joints. Some bones protect our internal organs. Some bones provide a framework for the body (just as the spokes of an umbrella provide a framework). Some bones contain red marrow that produces blood cells and yellow marrow that also stores fat.

Major Bones of the Skeletal System