| Question | Answer |
| Bone or osseous tissue | -dense supportive connective tissue
-contains specialized cells
-composed mostly of solid extracellular matrix with college fibers |
| Inorganic matrix | 65% of total bone weight, composed of minerals |
| Organic matrix | 35% of bone total weight, composed of college and other ECM components |
| Dense matrix | Deposit of calcium salts |
| Osteocytes (bone cells) | Within lacunea organized around blood vessels |
| Canaliculi | Narrow passageways that allow for exchange of nutrients, wastes, and gases between osteocytes. |
| Periosteum | -covers outer surface of Bones (except joints)
-consists of outer fibrous and inner cellular layers
-connected to bone by perforating fibers |
| Perforating fibers | Collagen fibers |
| What makes up almost 2/3 of bone Mass? | Calcium phosphate Ca3(PO4)2 |
| How much of the body calcium is stored in bone? | 85% |
| Hydroxyapatite | Mixture of calcium phosphate and calcium hydroxide and is a formed Crystal. |
| What makes bone one of the strongest and hardest substances of the body? | Crystalline structure |
| Characteristics of a bone lacking a calcified matrix | Looks normal but is very flexible |
| Organic bone matrix (osteoid tissue) composed of? | -protein fibers
-glycosaminoglycans
-proteoglycans
-glycoproteins |
| How much of the bone Mass is callogen fibers? | 1/3 |
| What is torsion | Twisting |
| What is tensile | Stretching |
| What help draw water into the osteoid matrix? | Glycosaminoglycans and proteoglycans |
| Bone cells make up how much percent of bone Mass? | 2% |
| What are the 4 types of bone cells | -osteogenic
-osteoblasts
-osteocytes
-osteoclasts |
| Functions of osteogenic cells | -mesenchtmal stem cells that divide to produce osteoblasts
-located in inner cellular layer of periosteum and in endosteum
-metabolically and mitotically active
-assist in fracture repair |
| Osteogenic cells | Stem cells whose divisions produce osteoblasts |
| Osteoblasts | Bone building cells
-immature cells that produce new bone matrix during osteogenesis (ossification)
- surround themselves themselves with home material and become osteocytes |
| Osteoid | Matrix produced by osteoblasts that has not yet become calcified |
| Osteocytes | Mature bone cells that are surrounded in bone matrix.
-less metabolically active, but still critical for maintaining bone matrix
-remain interconnected via cytoplasmic extensions that pass through canaliculi |
| Major functions of osteocytes | -maintain protein and mineral content of matrix
-help repair damaged bone |
| Osteoclasts (bone dissolving cells) | -large and are multinucleated
-dissolve and remove bone matrix
-secrete about and protein-digesting enzymes |
| What is a resorbtion Bay? | Where osteoclasts are located in shallow depressions of external bone surface |
| Osteolysis | Bone degredation by osteoclasts |
