This is very interesting thoughts of why do we have a skeleton? There are two main jobs that the skeleton does it supports the body, and it protects delicate organs. The skeleton is the frame that holds man erect. It is made mostly of bones.
A baby is born with as many as 270 small, rather sot bones in his framework. A fully grown person usually has 206, because some bones become fused, or grow together. Bones it together at joints and are held fast by ligaments, which are like tough cords or straps. Some joints can be moved freely. For example, when you run, you move your legs at the hip and knee joints.
When you throw a ball, you move your arm at the shoulder and elbow joints. Moreover, some joints cannot be moved at all. At the base of the spine the bones are fused, forming one bony plate that fits into another.
Neither move, the joints in your skull are very solid, too, except for those in the jaws. The protection that the skeleton provides includes the hard, bony cap o the skull. This protects the brain. The rib cage protects the heart and lungs. And the backbone, or hollow spinal column, protects the spinal cord, the body trunk line of nerve cables. The backbone is actually a string of small bones.
It is very hard for us to think of bone as living tissue, but it is. It grows when a person is young. For example the thigh bone may triple in length between the time a person is born and the time he is fully grown.
Bones grows in length and thickness as calcium and other minerals are added to them. And since bone is living tissue, it must be fed. The outside of the bone is covered with a thin, tough skin. The skin holds many tiny blood vessels that carry food to the bone cells.
The middle of a bone is spongy and filled with marrow. Some of the marrow is a storehouse for fat, and other marrow makes red blood cells. There are six major skeleton purposes, movement, and protection, storage of minerals, endocrine regulation and production of blood cells. Also, men and women have an average 12 pairs of ribs, in some special cases; few have 13 or 11 pairs of ribs.
A human bone grows and changes over the whole life. Furthermore, a healthy skeleton needs daily exercise, walking, jumping, skipping; support the human bones to grow strong. Also, a healthy bone mass in the skeleton reaches utmost density around the age of thirty. Our lungs can collapse without rib cage, and intercostals muscle.