What Is the Purpose of Bones in Human Body?
We have bones to give us shape and support the body, to protect and contain the body’s delicate vital organs, and to help us move about, often stereotyped as simply a protective and supportive framework for the body. Though they do perform these functions, bones constantly remodel and change shape to adapt to the daily forces placed upon it.
Moreover, bone stores crucial nutrients, minerals, and lipids and produces blood cells that nourish the body and play a vital role in protecting the body against infection. All these functions make the approximately 206 bones of the human body an organ that is essential to our daily existence.
Bones are made from living tissue, composed of special cells which secrete around themselves hard material rich in calcium salts. In a child the bones are soft and cartilaginous (cartilage is gristle, the elastic substance of the ear or nose). Bone-making, or ossification, is a gradual process.
A baby has as many as 270 bones, but an adult only 206, for some bones grow together as they get older. All bones have a middle cavity filled with a yellow or red fatty substance called bone marrow, the blood-making factory of the body, which also keeps bones light without reducing their strength.
The basic part of the skeleton is the spine, which has 33 bones or vertebrae. The spine carries the weight of the body, is extremely flexible and contains and protects the delicate spinal cord. The skull shelters the brain while the ribs protect the heart and lungs. Bones fit together at the joints and are held firm by ligaments, which are made of tough tissue like cords or straps. Inside each joint is a thin membraneous bag which secretes a lubricant to make the joint move smoothly.
Some glide on one another, as the lower jaw slides on the upper. Some, such as the elbow and the knee, hinge on each other and others, like the hip, make a ball and socket joint. Bones are sometimes fused together and immovable, as in the five large, lower vertebrae called the sacrum.
The skeletal system consists of bones, cartilage, and the membranes that line the bones. Each bone is an organ that includes nervous tissue, epithelial tissue (within the blood vessels), and connective tissue (blood, bone, cartilage, adipose, and fibrous connective tissue).
Bones have many functions, including the following:
- Support: Bones provide a framework for the attachment of muscles and other tissues.
- Protection: Bones such as the skull and rib cage protect internal organs from injury.
- Movement: Bones enable body movements by acting as levers and points of attachment for muscles.
- Mineral storage: Bones serve as a reservoir for calcium and phosphorus, essential minerals for various cellular activities throughout the body.
- Blood cell production: The production of blood cells, or hematopoiesis, occurs in the red marrow found within the cavities of certain bones.
- Energy storage: Lipids, such as fats, stored in adipose cells of the yellow marrow serve as an energy reservoir.