Anatomy and Cell Biology 3309 Lecture 10: Histology Lecture 10
Document Summary
Endochondral ossification: growth of long bones, vertebrae, pelvis and base of skull. Intramembranous ossification: growth of skull, maxilla, and most of the mandible. Bone formation that requires a cartilage template. The area where the bone is going to form is initially cartilage. In humans this process starts in the 6-7th week of life relatively early in the embryo. In the embryo, it surrounded by other cell types and tissues (skeletal muscle, blood vessel, etc. ) Image: has begun the process of endochondral ossification, the top part is cartilage, the lower part in the diaphysis is turning into bone. Interstitial growth (left: mitosis of chondrocytes within cartilage, synthesis of new cartilage matrix. Appositional growth (right: differentiation of cells within the perichondrium to chondrocytes, deposition of new cartilage matrix upon the existing cartilage. First time that occurs, is that in the center of the diaphysis, the cartilage starts to calcify. The cartilaginous model is surrounded by a perichondrium.