Term
| what are the functions of bone |
|
Definition
| support fleshy structures, protect organs, permit movement, harbor bone marrow, store calcium and phosphate, metabolically active |
|
|
Term
| does bone bleed when it breaks, why |
|
Definition
| yes, because it is highly vacular |
|
|
Term
| what type of tissue is bone |
|
Definition
|
|
Term
| what does bone tissue contain |
|
Definition
| matrix and cellylar elements |
|
|
Term
|
Definition
| mineralized intracellular material |
|
|
Term
| what types of cells are in bone |
|
Definition
| osteocytes, osteoblasts, osteoclasts |
|
|
Term
| where are osteocytes found |
|
Definition
| in spaces (lacunae) in the matrix |
|
|
Term
|
Definition
| make organic compounds (mostly collagen I) in bone matrix on top of old matrix |
|
|
Term
|
Definition
|
|
Term
|
Definition
| cylindrical spaces that penetrate bone matrix |
|
|
Term
| what is the function of canliculi |
|
Definition
| allow exchange of materials between osteocytes and blood capillaries because things cannot diffuse across bone matrix |
|
|
Term
| what is the tissue lining the external and internal surfaces of bone called |
|
Definition
|
|
Term
| what cells are in the endosteum and periostrum |
|
Definition
|
|
Term
| what compounds to osteoblasts make |
|
Definition
| type I collagen, peoteoglycans, glycoproteins |
|
|
Term
| where are osteoblasts found |
|
Definition
| surface of bone tissue side by side |
|
|
Term
| what does an active osteoblast look like |
|
Definition
| cuboidal to columnar with a basophilic cytoplasm |
|
|
Term
| what does an inactive osteoblast look like |
|
Definition
| flattened with less basophilia |
|
|
Term
| where are osteocytes located |
|
Definition
| one in each lacunae with their cytoplasmic process in the canaliculi |
|
|
Term
| how do single osteocytes in lacunae communicate |
|
Definition
| with gap junctions through canliculi, they exchange things between cells and across the ECM |
|
|
Term
| describe the shape and contents of osteocytes |
|
Definition
| flat almond shape, reduced RER and golgi, more condensed chromatin |
|
|
Term
| what happens when an osteocyte dies |
|
Definition
| it is reabsorbed, but they are usually long living |
|
|
Term
| describe the shape and contents of an osteoclast |
|
Definition
| large, multinucleated (5-50), motile, when active the portion facing the matrix is folded into irregular projections called the ruffled border |
|
|
Term
| where do osteoclasts come from |
|
Definition
| fusion of bone marrow derived from mononuclear cells |
|
|
Term
| where are osteoclasts found, why |
|
Definition
| in depressions in the matrix called howship's lacunae because they ate away some of the bone and are sinking into it (depressed pirate, arg :( ) |
|
|
Term
| what is the ruffled border, what does it do, what surrounds it |
|
Definition
| irregular projections on an active osteoclast on the portion facing the bone matrix, the site of adhesion between cell and bone matrix with villi entering matrix, creates a sealed microenivorment for bone reabsorption to occur, surrounded by clear zone |
|
|
Term
| what do osteoclasts do to break down bone |
|
Definition
| secrete collagenase and other enzymes. pump protons (acid) into the subcellular pocket dissolving the calcium salt crystals and digest the collagen of the matrix with collagenases |
|
|
Term
| why is parathyroid hormone released, what happens when it is |
|
Definition
| it is released because more calcium is needed in the blood. parathyroid binds to receptors on osteroblasts turning them off and making them release osteoclast activating factor so osteoclast activity will increase and bone will be broken down and Ca will enter the blood |
|
|
Term
| why is calcitonin released, what happens when it is |
|
Definition
| because there is too much Ca in the blood. calcitonin binds to osteoclast receptors turning them off so only osteoblasts are working and blood calcium is used to make bone |
|
|
Term
| what are the inorganic parts of the bone matrix |
|
Definition
| calcium, phosphate, hydroxyapatite, amorphous calcium phosphate, kydroxyapatite crystals, hydratoin shell, bicarbonate, citrate, magnesium, potassium, sodium |
|
|
Term
| what portion of bone matrix is inorganic |
|
Definition
|
|
Term
| what are the organic compounds of the bone matrix |
|
Definition
| type 1 collagen, ground substance |
|
|
Term
| what is in the ground substance of the bone matrix |
|
Definition
| proteoglycan aggregates, structural glycoproteins (bone specific) |
|
|
Term
| what is the function of the bone specific glycoproteins in the bone matrix |
|
Definition
| promote mineralization of bone |
|
|
Term
| what is the function of the molecules in the organic portion of the bone matrix |
|
Definition
| create hardness and resistance |
|
|
Term
| what is the periosteum made of |
|
Definition
| collagen fibers and fibroblasts, sharpey's fibers, osteoprogenitor cells |
|
|
Term
| what are sharpey's fibers, what is their function |
|
Definition
| periostral collagen fibers that penetrate the bone matrix binding periostem to bone |
|
|
Term
| what are osteoprogenitor cells, where are they found |
|
Definition
| fibroblast like cells with the potention to divide and differentiate into osteoblasts in the periosteum |
|
|
Term
| what is the endosteum made of |
|
Definition
| osteoprogenitor cells and some connective tissue, few fibroblasts, collagen |
|
|
Term
| which layer of bone is thinner, periosteum and endosteum |
|
Definition
|
|
Term
| what is the function of the periosteum and endosteum |
|
Definition
| provide continous supply of new osteoblasts for reapir and growth of bone |
|
|
Term
| what are the types of bone |
|
Definition
| compact, cancellous, primary, secondary |
|
|
Term
|
Definition
| dense areas without cavities |
|
|
Term
|
Definition
| areas with interconnecting trabeculated cavities filled with marrow |
|
|
Term
| what is another name for cancellous bone |
|
Definition
|
|
Term
| what type of bone is histologically the same as cancellous bone |
|
Definition
| microscopically compact, they have the same basic histological structure |
|
|
Term
|
Definition
| immature or woven, the first formed bone |
|
|
Term
|
Definition
|
|
Term
| when is primary bone seen |
|
Definition
| first to appear in development, fracture repair, other repair, usually temporary |
|
|
Term
| what does primary bone have in it |
|
Definition
| random collagen organization, low minerals, high ostecytes |
|
|
Term
| where is primary bone perminate |
|
Definition
| tooth sockets, sutures of skull, some tendenous intersections |
|
|
Term
| what is the temporary primary bone replaced by |
|
Definition
| secondary bone over time or due to remodeling |
|
|
Term
| where is secondary bone found |
|
Definition
|
|
Term
| what is secondary bone made of |
|
Definition
| collagen aranged in lamellae |
|
|
Term
| how are the secondary lamellae organized |
|
Definition
| paralled or concentric around a vascular canal |
|
|
Term
| what is the organization of lamellae in compact bone |
|
Definition
| typical organization, inner marrow cavity, outer layer is beneath the periosteum, has haverian and interstitial areas |
|
|
Term
| what is the haverian system |
|
Definition
| concentric lamellae between the inner and outer circumferential lamellae that surround a central canal of vessels, nerves, and loose connective tissue |
|
|
Term
| what is a interstitial lamellae |
|
Definition
| irregular shaped areas between haverian systems |
|
|
Term
| how many lamellae surround a haverian central canal |
|
Definition
|
|
Term
| what lines the haversian canal |
|
Definition
|
|
Term
| what does the haversian canal contain |
|
Definition
| blood vessels, nerves, connective tissue |
|
|
Term
| what does the haversian canal communicate with |
|
Definition
| marrow cavity, periosteum, and other canals |
|
|
Term
| how does the haversian canal communicate with other canals |
|
Definition
| by the transvers or oblique Volkmann's canals |
|
|
Term
| how are volkmann's canals different than lamellae |
|
Definition
| they perforate lamellae rather than having concentric canals at 90%, connect to lamellae |
|
|
Term
| describe the collagen fibers around a haversian canal |
|
Definition
| collagen fibers are paralled to eachother in ahelical course with the lamella, they change direction in each successive lamella, fibers in adjacent lamella intersect at right angles |
|
|
Term
| how does intramembranous ossification occur |
|
Definition
| in primary ossification centers mesenchyme condenses making spongy structure, bone cells differentate making osteoblasts, osteoblasts make bone, reapsorption and remodeling gives bone shape and texture but ossification happens more than remodeling |
|
|
Term
| what is endochronial ossification |
|
Definition
| desposition of bone matrix on a preexisting cartilage matrix |
|
|
Term
|
Definition
| reconstruction of bone that occurs during bone growth and through adult life |
|
|
Term
| what is the source of flat bones |
|
Definition
| frontal and parietal bones, part of the occipital and temporal bones, mandilble, contribute to the growht of short bones and thickening long bones |
|
|
Term
| where does intramembranous ossification occur |
|
Definition
| in the condensations of mesenchymal tissue, primary ossification center |
|
|
Term
| where is the starting point for bone fomation |
|
Definition
| primary ossification center |
|
|
Term
| what is the primary ossification center |
|
Definition
| groups of cells differentating into osteoblasts which make matrix then calcify it |
|
|
Term
| what are in the delineate cavities of intramembranous ossifying bone |
|
Definition
| capillaries, bone marrow cells, undifferentiated cells |
|
|
Term
| where does endochondral ossification occur |
|
Definition
| in a piece of hayline cartilage resembling a small version of the bone to be formed |
|
|
Term
| what boes does endochondral ossification make |
|
Definition
|
|
Term
| describe the process of endochondral ossification |
|
Definition
1. hayline cartilage model with perichondrium and cartilage forming cells
2. perichondria differentiates into bone forming cells making the bone collar, osteoblasts made
3. surrounding cartilage is killed as bone chokes it off, chondrocytes enlarge and are reabsorbed by the matrix as it calcifies
4. osteoclasts remodel it to the right shape and get rid of all non bone tissue except special spots
5. ossification centers from in the epiphesis (special spots we want growing bone)
6. as an adult a growth plates are replaced |
|
|
Term
| where does cartilage remain in secondary ossification centers during endochondral ossification |
|
Definition
| articular cartilage, epiphyseal cartilage that connects diaphysis |
|
|
Term
| what is the function of epiphyseal cartilage |
|
Definition
|
|
Term
| when do the epiphyseal plates close |
|
Definition
|
|
Term
| what are the zones of epiphyseal plate in order from epiphysis to diaphysis |
|
Definition
| resting zone, proliferative zone, hypertrophic cartilage zone, calcified cartilage zone, ossification zone |
|
|
Term
|
Definition
| area of eipihyseal cartilage with hayline cartilage without cellular changes |
|
|
Term
| what is the proliferative zone |
|
Definition
| area of eipihyseal cartilage where chondrocytes divide rapidly forming columns of stacked cells paralled to the long axis of the bone making cartilage matrix and lenghtening the bone |
|
|
Term
| what is the hypertrophic cartilage zone |
|
Definition
| area of eipihyseal cartilage where large chondrocytes with cytoplasmic glycogen reabsorb matrix and reduce it into a thin septa |
|
|
Term
| what is the calcified cartilage zone |
|
Definition
| area of eipihyseal cartilage where chondrocytes die and a thin septa of matrix becomes calcified |
|
|
Term
| what is the ossification zone |
|
Definition
| area of eipihyseal cartilage where bone tissue appears, boood capillaries and osteoprogenitor cells invate, osteoblasts form and deposit bone matrix over the calsified cartilage matrix |
|
|
Term
| how does calsification begin |
|
Definition
| by deposition of calcium salts on collagen fibrils |
|
|
Term
| how is calsification induced |
|
Definition
| by proteoglycans and high affinity calcium binding glycoproteins |
|
|
Term
| what do you need to calcify bone |
|
Definition
| by osteoblasts which release matrix vesicles, calcium binding proteins to increase calcium concentration, matrix vessicles to release osteoblasts, alkaline phosphate to increase phosphate |
|
|
Term
| when is bone remodeling very active |
|
Definition
|
|
Term
| what does bone do in response to stress |
|
Definition
|
|
Term
| what is the main metabolic role of bone |
|
Definition
| contains 99% of the body's calcium, resevoir of calcium and phosphate |
|
|
Term
| how does the bone get calcium to the rest of the body |
|
Definition
| continous interchange with the blood |
|
|
Term
| what are the mechanisms of calcium mobilization from bone |
|
Definition
| simple ion transfer, horomne action |
|
|
Term
| how does simple ion transfer of calcium work in the bone |
|
Definition
| transfer from hydroxyapatite crystals to the insterstitial fluid |
|
|
Term
| where does simple ion transfer of calcium work in the bone occur, why |
|
Definition
| mostly spongy bone, younger lamellae lose and recieve calcium more easily |
|
|
Term
| what hormones regulate calcium mobilization in bone |
|
Definition
| parathyroid and calcitonin |
|
|
Term
| what does parathyroid hormone do |
|
Definition
| promotes osteoclast absorption by using calcium by activating older osteoclast receptors, causes osteoblasts to stop making bone and secrete osteoclast activing factor |
|
|
Term
|
Definition
| inhibit bone matrix reabsorption stoping osteoclasts |
|
|
Term
| what is the function of the synovial joint |
|
Definition
| generall, unite long bones and have great mobility |
|
|
Term
| what are the parts of a synovial joint |
|
Definition
| ligament and a capsule of connective tissue with an articular cavity that has synovial fluid |
|
|
Term
| what are the layers of connective tissue in a synovial joint and their location |
|
Definition
| external fibrous dense and internal synovial with fibroblast like cells and macrophage like cells |
|
|
Term
|
Definition
| transparent, viscous, colorless, plasma dialysate with hyaluronic acid |
|
|
Term
| what is the function of synovial fluid |
|
Definition
| lubricare articular cartilage, supply nutrients and oxygen to the avascular articular cartilage |
|
|
Term
| where is the hyaluronic acid in the synovial fluid made |
|
Definition
|
|
Term
| what types of cartilage is articular cartilage |
|
Definition
|
|
Term
| what is the function of articular cartilage and why |
|
Definition
| resists pressure by the art due to collagen arangement, sock absorption due to proteoglycans and water |
|
|
Term
| how does the articular cartilage accomplish shock absprption |
|
Definition
| water is forced out of the matrix then electrostatic forces between GAGs force it to speing back allowing the water to return |
|
|
Term
| where is the marrow cavity of a long bone |
|
Definition
| in the center of the shaft, the diaphysis |
|
|
Term
| where is the metaphysis of a long bone |
|
Definition
| between the epiphysis and diaphysis |
|
|
Term
| were is the ephypisis of a long bone |
|
Definition
| on the ends marked by the epiphyseal plate |
|
|
Term
| what is the epiphyseal plate made of |
|
Definition
|
|
Term
| what is on the very ends of a long bone |
|
Definition
|
|
Term
| what is articular cartilage made of |
|
Definition
| hayline cartilage, no pericardium |
|
|
Term
| what are the functions of an osteocyte |
|
Definition
| maintain bone health, transport, physically non active |
|
|
Term
| where are osteoclasts made from |
|
Definition
|
|
Term
| what bone cells are macrophage like |
|
Definition
|
|
Term
| what do osteoblasts regulate |
|
Definition
| calcification and mineralization, they are required for it to work |
|
|
Term
| what do osteoblasts look like under EM |
|
Definition
|
|
Term
| how are osteocytes formed |
|
Definition
| when osteoblasts are laying down new matrix, some get burried in it and live in a lacunae with non-calcified matrix and become inactive and become osteocyte |
|
|
Term
|
Definition
|
|
Term
| what is the appositional growth |
|
Definition
| layer of new bone on top of existing bone |
|
|
Term
| how long can the chain of caniculi get |
|
Definition
|
|
Term
| what do the caniculi make up for |
|
Definition
| capillaries in bone being far away and the matrix not allowing diffusion |
|
|
Term
| what happens if osteocytes die |
|
Definition
|
|
Term
| what is the inorganic bone matrix made of |
|
Definition
| calcium, phosphate, hydroxyapetate crystals, calcium phosphate, |
|
|
Term
| what is hydroxyapetite crystals |
|
Definition
| plates along collagen in the ground substance that have a hydration shell allowing for calcium exchange (and other ion) exchange with the body fluids |
|
|
Term
| what are the gross kinds of bone |
|
Definition
|
|
Term
| what are the microscophic types of bone |
|
Definition
|
|
Term
| what is another name for compact bone |
|
Definition
|
|
Term
| how are lacunae and lamellae arranged in compact bone |
|
Definition
| lacunae are aranged between layers of lamellae |
|
|
Term
| where is the outer circumfrential lamellae located in difference to the inner |
|
Definition
|
|
Term
| what structural situation makes the osteon strong |
|
Definition
| alternating collagen directions in each ring |
|
|
Term
| other than the central canal, where are there vessels in the osteon |
|
Definition
| tiney ones between the lamellae |
|
|
Term
| describe the bone remodeling process |
|
Definition
| osteoclast cut shaft into the bone at the cutting zone as big as an osteon,osteoprogeneraror cells line the edge of the zone just cut and form new bone, outer osteon rings are older than inner due to this process, the hold is closed in until the central canal remains |
|
|
Term
| explain the process of fracture repair |
|
Definition
1. connective tissue proliferates stabilising with hayline cartilage
2. cartilage cells make cartilage
3. bone cells make primary bone
4. remodeling heals bone |
|
|
Term
| where is the primary ossification center located in long bone |
|
Definition
|
|
Term
|
Definition
| the area in the middle of the cartilage of the model for endochrondal ossification that has the first bone forming cells |
|
|
