The link below will provide you with an actual diagram.
Long bones are longer than they are wide. Often they are slightly curved to help them withstand pressure. Examples of long bones include the femur, fibula, tibia, humerus, radius, and ulna.
Long bones are composed of a shaft (diaphyses) and extremities (epiphyses).
The extremities are made of light spongy bone and lined with articulatory (articular) cartilage, which absorbs shock and reduces friction at freely moveable joints.
In the shaft, which is made of compact bone, you will find the medullary cavity, which contains blood cell-producing bone marrow (yellow in adults and red in children). Lining this cavity is the endosteum. Externally, the bones are surrounded by the periosteum, a tough fibrous membrane that adds to the bones' thickness.
The compact bone contains layers of concentric lamellae (bone plates) known as the osteon. These surround the Haversian canal, which travels lengthwise through the bone and encloses nerves and blood vessels. Connecting these canals with one another and with the medullary cavity and periosteum are Volkmann’s canals, which also contain blood vessels and nerves.