Which of the following statements about the structure of a long bone is correct?
The epiphysis is the shaft of the bone.
The articular cartilage covers the periosteum.
The medullary cavity is filled with yellow bone marrow.
The periosteum is the innermost layer of the bone.
The structure of a long bone includes the epiphysis (the rounded ends of the bone), the diaphysis (the shaft of the bone), the periosteum (a fibrous membrane that covers the outer surface of the bone), and the medullary cavity (a hollow cavity in the diaphysis that is filled with bone marrow). Yellow bone marrow is a type of bone marrow that is found in the medullary cavity and is primarily composed of fat cells. Articular cartilage is a smooth, slippery substance that covers the ends of bones at joints, and is not found on the periosteum.
Option 3 is the correct answer.