Veterinary Gross Anatomy

Long bone

LONG BONES

Long bones

• Have an elongated cylindrical part, the shaft or diaphysis and two expanded extremities or epiphysis.
• The shaft encloses the medullary cavity, which in life is occupied by yellow marrow.
• Long bones are found in the limbs and act as pillars for support and as levers. E.g. humerus, femur.
• Some long bones do not develop completely and their medullary cavity is very small or even absent which are called as aborted long bones. E.g. ulna of horse.
• Some bones though long they do not have a medullary cavity and are sometimes referred to as elongated bones. E.g. Ribs.