What is the comparison of the long bone and flat bone?

Flat bones have broad surfaces for protection of organs and attachment of muscles (ex. ribs, cranial bones, bones of shoulder girdle).
Long bones are longer than they are wide and work as levers. The bones of the upper and lower extremities (ex. humerus, tibia, femur, ulna, metacarpals, etc.) are of this type


At birth, all bone marrow is red. But in an adult, most red blood cells are produced in the flat bones, which still have red marrow. The long bones gradually fill with yellow marrow.