Bones In The Human Body

Humans have about 200 bones in the body, which are joined together and make up the skeleton. Your skeleton helps give your body its shape. The bones of your skull determine the shape of your head. Long bones hold muscles that shape your arms and legs. Rib bones curve to make the sides of your chest.
Your skeleton is the framework of your body. It holds you up and also helps you to move around.
Some bones protect your main inner organs. For example, your skull protects your brain. And your ribs make a rib cage around your heart and lungs.

What are bones made of?

Bones are hard tissues that are living parts of your body, just as your brain and heart are living parts. Bones contain cells that divide and multiply, causing you to grow. These cells are also always rebuilding the bony tissue to keep it strong. Rebuilding happens less as people grow older. So a broken bone will often heal much more quickly in a child than in an adult.
Bones store substances called minerals, which your body uses. Calcium is a mineral. It helps to make the bones hard.
Bones have a strong covering, called periosteum. Inside, there is a hard layer of compact bone. A long bone, such as the thigh bone, has spongy tissue at its ends, called cancellous bone, and soft marrow in its hollow center.

Some parts of your skeleton, such as your arms and legs, have only a few long bones. Other parts, such as your hands and feet, have many small bones.

How are bones held together?

Your bones are held together by strong, flexible straps called ligaments. The ends of the bones are covered with a smooth, rubbery substance called cartilage. This is the same kind of substance that forms the tip of your nose. Cartilage works like a cushion so that the bones don’t grind against each other. Cartilage is covered in a liquid called synovial fluid. This keeps the bones moving smoothly, like oil in the parts of a machine.

Interesting Facts About Bones

• Humans have about 300 bones when born. Some of these, fuse together creating a single bone. When maturity is reached, humans have 206 bones in the body.
• The teeth are not counted as bones.
• The greatest bone in the body, “the femur”, is around 1/4 of the persons height. 
• The smallest bone in the body is the stapes (stirrup) located in the middle ear, with size around 1/10 of an inch (2.8 millimetres).
• The only bone which is full-grown at birth is the stapes bone, and is situated in the ear.
• Hand, fingers and wrist make the area of the body with most bones - 54.
• The bones of an adult person make approximately 14 % of the total body weight.
• The bones are made of approximately 75 % of water
• Human bones start to grow from birth, until mid 20's. 
• Broken bones re-grow and repair themselves. 
• The human skeletal system has six major functions: 1. production of blood cells, 2. support, 3. movement, 4. protection, 5. storage of ions and 6. endocrine regulation.
• The Bone marrow makes up 4% of a human body mass.