Skeletal System
Types of Bones


Types of Skeletons
Skeletal Functions
Types of Bones
Structure of Long Bones
Microscopic Structure
Skeletal Development
Axial Skeleton
Appendicular Skeleton
Interactive Skeleton
Diseases, Disorders and Fractures

There are two basic types of bone tissue found in the skeletal system, along with cartilage.
Spongy Bone - Texture results from needlelike threads of bone (trabeculae) surrounded by a network of open spaces.  Spongy bone is found in epiphysis (ends) of long bones where the spaces contain red bone marrow responsible for reb blood cell formation. 
Compact Bone - Has a basic structural unit called osteon, composed of coencentric lamella, lacunae containing osteocytes and canaliculi, and covered with periosteum.


Cartilage - Structural unit is chondrocyte, contains a gel-like matric and lacks blood vessels.


Individual bones are classified by their basic shape and placed into four basic groups:
Long -  longer than they are wide, act as levers for the muscular system and bear the
    weight of the body  (Click for structure)
    Ex:  femur, tibia, fibula
Short -  basically shaped like a cube, allow skill and ease in movement
    Ex: carpals and tarsals


Flat - have broad surfaces for basic function: to protect organs
     Ex: skull, ribs, pelvic bones, shoulder blades
Irregular - doesn't fit into the other three categories
     Ex: vertebrae