Long bones are hard, dense bones that provide strength, structure, and mobility. The femur (thigh bone) is a long bone. A long bone has a shaft and two ends.
There are also bones in the fingers that are classified as "long bones," even though they are short in length. This is due to the shape of the bones, not the actual size.
Long bones contain yellow bone marrow and red bone marrow, which produces blood cells.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.