Bones have 5 functions:
1. Support: provides a framework that supports the body and cradles the softer organs, for example the ribcage supports the thoracic walls.
2. Protection: provides protection for the body's internal organs, reducing risk of injury to them. For example, the skull protects that brain and the vertebrae surrounds the spinal cords.
3. Movements: Skeletal muscles are attached to bones, therefore when the associated muscles contract they cause bones to move. As a result we can walk, grasp objects and breathe.
4. Mineral Storage: Bones are a reservoir for several minerals, including calcium and phosphate. When required, bone releases minerals into the blood - facilitating the balance of minerals in the body.
5. Blood Cell Formation:The bone marrow inside some larger bones produce red blood cells.
The Different Types of Bone Tissues and Cells
Bone is living tissue that makes up the body's skeleton. There are three types of bone tissue.
Compact tissue--the harder, outer tissue of bones
Cancellous tissue--the sponge-like tissue inside bones
Subchondral tissue--the smooth tissue at the ends of bones, which is covered with another type of tissue called cartilage.
There are several different types of bone cells;
Osteoblast--found within the bone, its function is to form new bone tissue
Osteoclast--a very large cell formed in bone marrow, its function is to absorb and remove unwanted tissue.
Osteocyte--found within the bone, its function is to help maintain bone as living tissue.
Hematopoietic--found in bone marrow, its function is to produce red blood cells.
Fat cells are also found within the bone marrow.
During infancy and youth, long bones grow interstitiatially by means of the epiphyseal plates. All bones grow in thickness by means of appositional growth. Most bones stop growing by adolescence with the exception of some facial bones(nose and lower jaw). In an adult bone, the area where the...