Problem description:
1. What is the morphological structure of bones? How does a long bone grow and thicken from childhood to adulthood?
2. Why are old people prone to fracture under the action of external force?
3. What are the main functions and clinical significance of periosteum?
Analysis:
Bone, composed of bone tissue, is hard and elastic, and is rich in blood vessels, lymphatic vessels and nerves. Living bone is a living organ, which has the characteristics of metabolism, growth and development, and has the ability of repair and reconstruction. Normal physical labor and regular physical exercise can promote the good development of bones.
Master the classification of bones:
Master the structure of bones
Bone consists of bone, periosteum, bone marrow, nerves and blood vessels.
Bone is the main component of bone, which is divided into two parts:
1, Dense is composed of closely arranged bone plate layers, which have strong compression and torsion resistance and are distributed on the surface of bone. The backbone of a long bone (the thinner part in the middle) is made of dense materials. In the skull cap, dense substances constitute the inner plate and the outer plate.
2. cancellous bone is composed of trabecular bone interwoven into a net, which is located inside the bone, such as the end of long bone (called epiphysis) and other types of bones. The cancellous bone of the skull is called the plank barrier. The arrangement of trabecular bone has certain regularity.
Periosteum-a membrane composed of fibrous tissue. The surface of fresh bone (except articular surface) is covered with periosteum. Periosteum can be divided into inner layer and outer layer, and the inner layer contains osteoblasts and osteoclasts. Periosteum is rich in blood vessels and nerves, which plays an important role in bone nutrition, regeneration, repair and sensation.