Our bones and their function

 

What is human bone?

Human bone is the hard and rigid  structure.  Hunan bone is made up of the connective tissue.Bone is also made up of the colleen fiber are strict and hardened by deposit of calcium phosphate. Our bones are consists of the compact bone with spongy bone.

Parts of the bones

There are two parts of the bones.

1-Compact bone 

2-Spongy bone

Compact bone 

Compact bone is dense and strong and also surrounded an attachment place for muscles.

Spongy bone

Spongy bone is a less high  rich  in blood vessels and also extremely porous and cavities of spongy bone posses bone marrow  where blood cells are  prepared

Type of bone cells which make bones of humans are three types as shown below.

Osteoblast

Osteocyte

Osteoclast

The first cell Osteoblast is bone forming cell. The second cell Osteocyte is the mature bone cell and  the third from of the cell is Osteoclast which is bone dissolving cells.

Process of development of the bones 

There are following steps in the process of the bone developments.

First of all in the development of the bone when bone is replacing  cartilages tissues the osteoblast invade and also dissolve the cartilaginous. In the second step osteoblast is replaced it with the bone. In the third step as bone grows the matrix of bone is hardened and  the osteoblasts are commonly entrapped in it.

Where bone occur

There are more sites in which our bones occur but the largest bone of our body is bone of the ran and the smallest bone of our body is the bone of the our ear. In human bones are divided by two parts first part is the Axial skeleton and the second part is the Apendicular skeleton. In our body bones are present in different parts of the body such as the legs, arms, hands, vertebra, in foots, face.

Axial skeleton

Axial skeleton includes totally fifty five bones which are present in the skull vertebrae, ribs and the sternum.

Skull

It includes cranium and facial structures.

Vertebral column 

Vertebral column  extends from the skull to the pelvis to from backbone that protects the spinal cord.

Rib cage

It involves of the twelve pairs of the ribs which articulate with the thoracic vertebrae.

2-Appendicular skeleton

Appendicular skeleton includes three types of bones like pectoral girdle and pelvic girdle and also appendages

Joints are also parts of our bones they occur where two bones meet to each others. Our joints provide support to our bones and we can walk with the help of bones and their joints and also we can movie from one place to another through these bones and the joints.

Types of the joints 

There are three types of joints as shown below.

Fibrous joints

Cartilaginous joints

Synovial joints 

Synovial joints  is further classified into the hinge joint and Ball and socket joint.

Hinge joint

Hinge joint are those joint types of joints which only allow movements in two directions. These joints are present in our elbow and knew.

Ball and Socket joint 

Ball and Socket joint  are those joints that allows the movements in all the directions.These joints are present in the  hip joint and shoulder are ball and the socket joint.