BIOLOGY 20 Lecture Notes - Lecture 8: East Los Angeles College, Intramembranous Ossification, Bone Marrow
Document Summary
Includes red bone marrow and yellow bone marrow. Yellow storing fat (backup supply of energy; great reserve) Also known as myeloid tissue= hemopoietic (blood cell forming) Contains reticular connective tissue, immature blood cells, and fat. In children, located in the spongy bone and. Starting to form what looks like skeleton. Parietal, frontal skull bones, mandible, clavicle, patella. Dermal ossification or bone growth within a membrane. Forms the flat bones of the fetal skull, mandible, and parts of clavicle. Development of ossification center: osteoblasts secrete organic extracellular matrix (osteoid) Embryonic mesenchymal cells get together, differentiate into committed osteoblasts lay down osteoid matrix osteoblasts. Calcification: calcium and other mineral salts are deposited and extracellular matrix calcifies (hardens) Formation of trabeculae: extracellular matrix develops into trabeculae that fuse to form spongy bone. As woven bone calcifies trabeculae fuse together, blood vessels get trapped and the periosteum also forms.
