Types and function of bones

Structure of the Long Bone

A typical long bone has a cylindrical osseous tissue structure. The cylinder protects a space known as the medullary cavity, which is home to bone marrow. A long bone is described as having a diaphysis (body) and an epiphysis (expanded heads) at each end. The diaphysis serves as the lever arm, strengthening the joints and providing a place for the attachment of bone ligaments and muscle tendons. Articular cartilage, a layer of hyaline cartilage, covers the joint surface where one bone meets another. Blood vessels feed the bone through tiny openings in the diaphysis known as nutrient foramina. Except for over the articular cartilage, the periosteum, a dense fibrous sheath, covers the periosteum's exterior. The periosteum is where tendons are connected. The development of bone and the healing of fractures both depend on the periosteum. Endosteum, a layer of reticular connective tissue, covers the interior surface of the bone. An epiphysial plate made of hyaline cartilage separates the diaphysis from the epiphysis in children and adolescents. Between the ages of 18 and 20, the epiphyses and diaphyses fuse, the epiphyseal plates vanish, and the bone stops growing longer.

Structure of Short, Irregular Flat Bone

These have a relatively thin layer of compact bone on the outside and spongy, red bone marrow-containing bone inside. Except for the inner layer of the cranial bones, where dura mater replaces periosteum, all of them are surrounded by it.

Blood and Nerve Supply of Bone

The nutrient artery, periosteal arteries, epiphyseal arteries, and metaphyseal arteries all contribute to the long bone's blood supply. The periosteal veins, epiphyseal and metaphyseal veins, and nutrient veins all transport blood away from the long bone. The periosteum is supplied by the sensory nerves.