Bones are divided by its magnitude and functions into the long bone (trabecular), short and flat (diagram 16). Long (trabecular) bones are the bones

Structure of bones (long, short and flat; the periosteum) [anatomical]

Bones are divided by its magnitude and functions into the long bone (trabecular), short and flat (diagram 16).

Long (trabecular) bones are the bones of the limbs and have two heads and the body. On their longitudinal cut in the central part can be seen the cavity, which is filled with red marrow in children and yellow — in adults. Trabecular bone body is composed of a dense (compact) tissue, and heads are of spongy bone tissue formed by membranes that are arranged in mutually perpendicular directions. Between the membranes of spongy substance is located red bone marrow — a blood formation organ. Heads of long bones have articular surfaces, coated with cartilage, which is composed of cells (chondrocytes) and hard connective tissue. Due to the cartilage cells the bone grows in length.

Diagram 16. Types of bones: 1 — trabecular (long bones): a) body; b) head; 2 — flat (blade); 3 — short spongy (vertebrae)

Flat (scapula, sternum) and short spongy (wrist, vertebrae) bones usually consist only of the sponge material, coated with a thin layer of compact substance. Taken from http://worldofschool.org

Outside the bone is covered with periosteum — a thin connective tissue that contains many blood vessels and nerves. Its inner layer is composed of cells that grow, reproduce and ensure the growth of bone in thickness, and heal it when it fractures. Bone supply is done due to the blood vessels of the periosteum. In attachment places of muscles the bone surface has roughness. They are increased in people who involved in sports from childhood or adolescence.

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Questions:
  • Identify interrelation of the bones anatomical structure with their physiological functions.

  • Explain why the bone grows.

  • What type of tissue are the bone and cartilage ones?