Question | Answer |
What type of collagen is bone made of? | Collagen type 1 |
Name of extracelluar matrix of bone | Osteoid |
What happens to osteoid which gives bone it's rigidity and strength and by deposition of which substance? | Mineralisation, Calcium Hydroxyapatite |
Osteoblast | Synthesise osteoid and mediate mineralisation |
Osteoblasts are found... | lined up along bone surface |
osteoclast | Large multinucleated phagocytic cells capable of eroding bones |
Osteocytes | Inactive osteoblast trapped within formed bone |
Osteoblast and osteoclast derives from... | Primitive mesenchymal (stem) cell called osteoprogenitor cell |
Osteoclast derives from | Macrophage-monocyte cell line |
Is bone vascularised and metabolically active? | Yes |
List some of the functions of bone? | *Bone tissue supports fleshly structure
*Protects vital organ e.g. cranial, thoracic cavaty
*Bone marrow, where blood cells are formed
*Reservoir of calcium, phosphate and other ions and their orderly intake and uptake from blood
*Act as lever |
Shape osteoblast when synthesising osteoid | Large broad cuboidal shape |
Organelles abundant in osteoblast... | REM,Golgi apparatus |
Describe the structure of inactive osteoblast? | Narrow attenuated spindle-shaped. Virtually undetectable except long narrow nucleus. |
In areas of bone undergoing resorption, osteoclast lie within enzymatically etched depression in matrix known as _________. | Howship's lacunae |
In active osteoclast, the surface-facing bone matrix is folded into irregular, often subdivided projections, forming __________ . | Ruffled border |
Role of ruffled border | *Secretes organic acids to dissolve minerals
*Secretes lysosomal proteolytic enzymes to destroy organic osteoid matrix |
Osteoclast resorption contributes to... | Bone remodelling in response to growth and mechanical stresses |
Arrangement of collagen in woven and woven and lamellar bone | random, regular parallel bands |
Woven and lamellar bones are found in... | Woven ==> Fetal bone development Lamellar ==> Adult bone |
Rapidly formed ______ bone is eventually remodelled to form ______ lamellar bone. | Woven, Lamellar |
Name the two types of lamellar bone. | 1) Compact (cortical) bone 2) Cancellous (medullary) bone |
Diaphysis is occupied by _________ bone | Compact |
Medullary cavity is occupied by _______ bone | Cancellous |
Cancellous bone consists of a network of fine, ______ plates called _______ separated by intercommunicating spaces. | irregular, trabeculae |
Articular cartilage are found in which bone region? | Epiphysis |
Periosteum | External fibrous surface of the bone which inserts muscle, tendons and ligaments. |
Endosteum | Covers innter surface of bones, including trabeculae of cancellous bone |