Bone Flashcards
What are the 4 main functions of Bone?
Mechanical, Protection, Haematopoiesis and Metabolic.
What is Endochondral Ossification?
Bone forms as cartilage during development. Blood vessels and Osteogenic cells invade cartilage framework. The cartilage then remains as growth plates until they fuse at 18/21.
What is Intramembranous Ossification?
Bone forms as fibrous plate. Bone cells differentiate from fibroblasts and haemopoietic precursors. No cartilaginous phase.
What bones do each type of ossification form?
INTRAMEMBRANOUS OSSIFICATION: forms the flat bones of the skull, face, jaw, and center of clavicle. bone is formed in sheet-like layers that reseamble a membrane. ENDOCHONDRAL OSSIFICATION: forms most bones in the body, mostly long bones, and replace cartilage with bone.
What 3 things is bone composed of?
Water, Protein and minerals
What main kind of proteins does bone protein contain?
Type I collagen (toughness)
Growth factor proteins
Others
What main mineral does bone contain?
Hydroxyapatite
What type of bone makes up the epiphyses?
Trabecular/spongy bones
What function does trabecular bone serve?
Softer interface at joints
What type of bone makes up Diaphysises?
Cortical Bone.
What function does cortical bone serve?
Denser sheets, gives bone its strength.
What function do Osteoblasts and Osteoclasts serve?
They make sure that bone undergoes a constant process of maintenance and renewal.
What do Osteoclasts do?
They are bone resorbing cells.
What do Osteoblasts do?
They lay down more bone where Osteoclasts have removed it.
What do Osteocytes do?
They are sensors of mechanical pressure and damage.
