What Are the Functions of Bones in the Human Body?
Bones function to give the body strength, protection and form. There are 206 bones in the adult human. Some bones are large, such as the femur, or thighbone, to give support to the body. Other bones are very small, such as the stapes or middle ear bone, which functions in hearing. Regardless of size or shape, bones have some similarity in terms of structure and composition.
-
Composition
-
The outer part of bone is composed of hard material. This hard material is made up of hydroxyapatite and proteins. Hydroxyapatite is made up of minerals, a large part of which is calcium and gives bones their strength. The central portion of bone is composed of bone marrow. Nerves and blood vessels are also components of bone, as bone is constantly undergoing a process of remodeling. Every 10 years, each bone in the body is completely regenerated.
Protection
-
Bones protect the internal organs and provide form to the body. The strength of the bones absorb large amounts of force if the body is struck or if one falls. The skull protects the brain, the ribs and sternum protect the heart and lungs and the vertebra (spinal column) protects the spine. The skull also gives shape to the face.
-
Cell Production
-
Bones are important in the production of red blood cells which carry oxygen and waste products from cellular metabolism. Red blood cells are produced in the bone marrow, or the central portion of the bones. In addition, white blood cells and blood platelets are produced in the bone marrow. Stem cells, or the precursor cells which can become many different types of body cells, are also found in the bone marrow.
Mineral Reserve
-
Calcium is stored in bones. This mineral is essential for contraction of the body muscles. Other minerals stored in the bone include phosphorus, potassium, manganese, silica, zinc, selenium, sulfur and other trace minerals. In order for bones to properly absorb these minerals vitamin D must be present.
Movement
-
Bones meet other bones at areas called joints in the body. The joints give the body flexibility and allow for movement. Cartilage lines the bones' surface in the joint. If the cartilage becomes damaged arthritis will occur. This can limit the body's movement and flexibility. Ligaments join the bones together and help to make the joint stable. Another function of bones is to provide a point of attachment for soft tissues. Muscles attach to the bones by tendons-strong, fiber like tissues. The tendons allow the muscles to pull on the bones to cause movement.
-
