BIO 11 Lecture Notes - Lecture 7: Hyaline Cartilage, Ossification Center, Bone Remodeling
Document Summary
Can sense pressure, release compounds to increase bone mass &encourage bone rebuilding. Lay down the organic parts of the bone (collagen) and evolve into osteocytes. Break down bone matrix for remodeling and release of acids/enzymes in response to parathyroid hormone. Bone remodeling is performed by both osteoblasts and osteoclasts. Begins during the embryonic period, continuing during post-natal development. Endochondral - built on a hyaline cartilage model. Step 1: cartilage cells (chondroblasts) in the external surface (perichondrium) differentiate into osteoblasts. Calcification and cell death of internal cartilage cells. Osteoblasts enter through new foramen and build bone from the inside. Secondary ossification centres don"t tend to begin developing until the time or shortly after birth. Osteoclasts begin digesting newly formed bone from step 3 to create medullary cavity. Cartilage only located between shaft and ends on articular surfaces. Intramembranous - built on a membrane of embryonic connective tissue: osteoblasts develop in the primary ossification center, newly formed osteoblasts secrete organic matrix.
