BIOL 129 Lecture Notes - Lecture 2: Bone Marrow, Medullary Cavity, Wormian Bones
Document Summary
The skeletal system: a dynamic system of connective tissue. Perpetual construction site constantly broken down and being re-built. Functions of bones: (1) protection: of soft underlying tissues/organs. Ex: rib cage protects heart, lungs, etc. (2) erythropoiesis: red blood cell production. A baby is born with 300+ bones (~302) Babies have more bones for more flexibility to make delivery easier and more flexible through the birth canal. Flat: will usually protect underlying, soft tissues; large surface area for muscles to attach to. Irregular: bones that don"t fit into other categories; oddly shaped. Sesamoid bone: small bones embedded within tendon where it passes over a joint. Wormian bones: extra irregularly shaped bone pieces that occur within a suture in the cranium. Epiphysis: ends of bone covered with cartilage. Medullary cavity: filled with yellow bone marrow. Periosteum (outside): membrane wrapping around bone (except joint cavity) Tough membrane covering bone but not the cartilage.
