long bone

Long bones are found in the upper arm and forearm, thigh and lower leg, palms, soles, fingers and toes. They are characterized by diaphysis and epiphysis portions and contain a marrow cavity. The humerus and the femur are the two most common examples of the long bone.

Diaphysis
(Or shaft of the long bone.) It is a hollow tube made of hard compact bone. It is very hard, and strong, but lightweight enough to allow for easy movement.

Medullary Cavity
This is the hollow area inside the diaphysis of the bone, and contains soft yellow bone marrow.

Epiphysis
These are the ends of your typical long bone. Red bone marrow, which is very much hemopoietic, fills in the small spaces in the sponge bone that makes up the epiphysis. The epiphyseal plates allow for extra growth in the bone. Some chiropractors are skilled enough to determine your growth patterns just by looking at your x-ray.

Articular Cartilage
A thin layer of cartilage covering each epiphysis. It functions pretty much like a rubber cushion at the ends of bones.

Periosteum
It is a strong fibrous membrane covering the long bone except at the joint surfaces where it is covered by articular cartilage.

Endosteum
A fibrous membrane that lines inside of the medullary cavity.