PHTY100 Lecture Notes - Lecture 4: Bone Marrow, Connective Tissue, Endochondral Ossification
Document Summary
Release enzymes that digest the mineral components of bone matrix. Regulate blood calcium level: bone tissue categorized as compact or spongy. Spongy: lacks osteons, lamella arranged in lattice of thin columns called trabeculae, spaces between trabeculae make bone lighter, trabeculae support and protect red bone marrow, blood cell production occurs in spongy bone. Compact: components arranged into repeating structural units called osteons or haversian systems, osteons consist of a central canal with concentrically arranged layers of bone matrix (lamellae, on each lamellae are a series of lacunar (house osteocytes) Ossification: bone grows through ossification, replacement of a connective tissue model with bone tissue, either intramembranous or endochondral. Intramembranous: original model highly vascularised mesenchyme (foetal connective tissue that can become different types of body tissue, bones of skull and clavicles. Endochondral: original model is cartilage, all bones except skull and cartilage develop this way, commences before birth, continues through childhood and into early adulthood.
