Term
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Definition
| Small rounded projection. Site of muscle and ligament attachment |
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Term
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Definition
| Large rounded projection. Site of muscle and ligament attachment |
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Term
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Definition
| Narrow, prominent ridge of bone. Site of muscle and ligament attachment. |
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Term
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Definition
| Large, blunt, irregular surface. Site of muscle and ligament attachment |
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Term
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Definition
| Narrow ridge of bone, less prominent than crest. Site of muscle and ligament attachment. |
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Term
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Definition
| Raised area above a condyle. Site of muscle and ligament attachment. |
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Term
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Definition
| Sharp, slender projection. Site of muscle and ligament attachment. |
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Term
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Definition
| Any bony prominence. Site of muscle and ligament attachment. |
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Term
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Definition
| bony expansion carried on a narrow neck. projection that helps form joints |
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Term
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Definition
| smooth, nearly flat articular surface. Projection that helps to form joints |
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Term
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Definition
| Rounded articular projection. Projection that helps to form joints. |
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Term
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Definition
| armlike bar of bone; protrusion. Projection that help to form joints. |
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Term
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Definition
| Canal-like passageway. Allows blood vessels and nerves to pass through |
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Term
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Definition
| Cavity within a bone. Allows blood vessels and nerves to pass through. |
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Term
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Definition
| Shallow, basin-like depression. Allows blood vessels and nerves to pass through. |
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Term
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Definition
| Furrow. Allows blood vessels and nerves to pass through |
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Term
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Definition
| narrow, slit-like opening. Allows blood vessels and nerves to pass through. |
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Term
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Definition
| round or oval opening through a bone. Allows blood vessels and nerves to pass through |
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Term
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Definition
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Term
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Definition
| honeycomb of trabeculae filled with yellow bone marrow. Internal portion |
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Term
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Definition
| Tubular shaft that forms the axis of long bones. Composed of compact bone that surrounds the medullary cavity. Yellow bone marrow (fat) is contained in the medullary cavity. |
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Term
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Definition
| Expanded ends of long bones. Exterior is compact bone, and the interior is spongy bone. Joint surface is covered with articular (hyaline cartilage). Epiphyseal line (metaphysis) separates the diaphysis from the epiphyses. Remnant of epiphyseal plate hyaline cartilage that lengthens the bones during childhood. |
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Term
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Definition
| double-layered protective membrane of the bone. Anchoring point for tendons and ligaments. Outer fibrous layer is dense regular connective tissue. Inner osteogenic layer is composed of osteoblasts and osteoclasts. Richly supplied with nerve fibers, blood, and lymphatic vessels which enter the bone via nutrient foramina. Secured to underlying bone by Sharpey's fibers. |
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Definition
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Term
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Definition
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Term
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Definition
| delicate membrane covering internal surfaces of the bone. |
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Term
| Structure of short, irregular, and flat bones |
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Definition
| Thin plates of periosteum-covered compact bone on the outside with endosteum-covered spongy bone (diploe) on the inside. Have no diaphysis or epiphyses. Contain bone marrow between the trabeculae. |
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Term
| Location of Hematopoietic Tissue: Infants |
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Definition
| Found in the medullary cavity and all areas of spongy bone. |
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Term
| Location of Hematopoietic Tissue: Adults |
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Definition
| Found in the diploe (endosteum covered spongy bone) of flat bones, and the head of the femur and humerus |
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Term
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Definition
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Term
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Definition
| Osteon. The structural unit of compact bone. |
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Term
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Definition
| Weight-bearing, column like matrix tubes composed mainly of collagen |
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Term
| Haversian (central) canal |
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Definition
| central channel containing blood vessels and nerves. Haversian runs vertically |
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Term
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Definition
| Perforating canals, channels lying at right angles to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian canal. Volkmanns's run Horizontally. |
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Term
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Definition
| mature bone cells. found between lamellar junctions |
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Term
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Definition
| small cavities in the bone that contain osteocytes. Found between lamellar junctions |
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Term
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Definition
| hairlike canals that connect lacunae to each other and the central canal. Allow nutrients and waste to be transferred from cell to cell. Found between lamellar junctions |
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Term
| Microscopic Structure of Spongy Bone |
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Definition
| Appears to be unarranged. No osteons. Trabeculae arrange along lines of stress to help spongy bone resist stress |
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Term
| Microscopic Structure of Compact Bone |
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Definition
| Haversian System or osteon, lamella, haversian canal, volkmann's canals, osteocytes, lacunae, canaliculi |
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Term
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Definition
| unmineralized bone matrix composed of proteoglycans, glycoproteins, and collagen |
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Term
| Organic Chemical Composition of Bone |
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Definition
| Osteoblast, Osteocytes, Osteoclasts, Osteoid |
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Term
| Inorganic Chemical Composition of Bone |
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Definition
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Term
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Definition
| Mineral Salts. Sixty-five percent of bone by mass. Mainly calcium phosphates. Responsible for bone hardness and its resistance to compression. |
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Term
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Definition
| "middle" cavity. marrow cavity |
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Term
| Osteogenesis/Ossification |
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Definition
| process of bone tissue formation |
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Term
| Formation of the Bony Skeleton |
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Definition
| Begins at week 8 of embryo development. |
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Term
| Intramembranous ossification |
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Definition
| Bone develops from a fibrous membrane |
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Term
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Definition
| bone forms by replacing hyaline cartilage |
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Term
| Intramembranous Ossification |
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Definition
| Formation of most of the flat bones of the skull and clavicles. Fibrous connective tissue membranes are formed by mesenchymal cells. |
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Term
| Intramembranous Ossification: Step 1 |
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Definition
| Ossification center appears in the fibrous connective tissue membrane. Selected mesenchymal cells cluster and differentiate into osteoblasts, forming an ossification center |
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Term
| Intramembranous Ossifcation: Step 2 |
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Definition
| Bone matrix (osteoid) is secreted within the fibrous membrane. Osteoblasts begin to secrete osteoid, which is mineralized within a few days. Trapped osteoblasts become osteocytes. |
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Term
| Intramembarnous Ossification: Step 3 |
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Definition
| Woven bone and periosteum form. Accumulating osteoid is laid down between embryonic blood vessels, which form a random network. The result is a network of trabeculae instead of lamella. Vascularized mesenchyme condenses on the external face of the woven bone and becomes the periosteum. |
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Term
| Intramembranous Ossification: Step 4 |
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Definition
| Bone collar of compact bone forms and the red marrow appears. Trabeculae just deep to the periosteum thicken, forming a woven bone collar that is later replaced with mature lamellar bone. Spongy bone (diploe) consisting of distinct trabeculae, persists internally and its vascular tissue becomes red marrow |
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Term
| Intramembarnous Ossification: Summary |
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Definition
| Mesenchymal cells > Ossification Center with osteoblasts > Osteoblasts secrete osteoid within fibrous membrane > osteiod mineralized and trapped osteoblasts become osteocytes > osteoid laid down between embryonic blood vessels forming trabeculae, vascularized mesenchyme condenses on external face fo woven bone and becomes periosteum > trabeculae just deep to periosteum thicken, forming woven bone collar (later replaced with lamellar bone) > Spongy Bone persists internally and vascular tissue becomes red marrow |
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Term
| Endochondral Ossification |
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Definition
| Begins in second month of development. Uses hyaline cartilage 'bones' as models for bone construction. Rquires breakdown of hyaline cartilage prior to ossification |
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Term
| Endochondral Ossification: Step 1 |
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Definition
| Formation of bone collar around hyaline cartilage model: Perichondrium covering the hylaine cartilage "bone" is infiltrated with blood vessels, converting it to a vascularized periosteum. CHange in nutrition causes mesenchymal cells to specialize into osteoblasts. Osteoblasts on the nnewly converted periosteum secrete osteoid against the hyaline cartilage diaphysis encasing it in a bone collar. |
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Term
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Definition
| Forms essentially all bones below the base of the skull |
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Term
| Endochonral Ossification: Step 2 |
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Definition
| Cavitation of the hyaline cartilage within the cartilage model: As the bone collar forms chondrocytes within the shaft hypertrophy (enlarge) and signal the surrounding cartilage matrix to calcify. Calcified cartilage matrix dies due to not being able to receive nutrients. Chondrocytes die and matrix deteriates. Cavities form but bone collar stabilizes the model. Cartilage elsewhere continues to grow, causing model to elongate |
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Term
| Endochondral Ossification: Step 3 |
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Definition
| Periosteal bud invades the internal cavities and spongy bone forms: Forming cavities are invaded by a periosteal bud, made up of a nutrient artery and vein, lymphatics, nerve fibers, red marrow elements, osteoblasts, and osteoclasts. Osteoclasts partially erode the calcified cartilage matrix,a nd the osteoblasts secrete osteoid around the remaning fragments of hyaline cartialge, forming bone-covered cartilage trabeculae. Beginning of spongy bone formation |
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Term
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Definition
| Collection of elements containing a nutrient artery and vein, lymphatics, nerve fibers, red marrow elements, osteolbasts, and osteoclasts. Part of Endochondral Ossification |
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Term
| Endochondral Ossification: Step 4 |
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Definition
| Diaphysis elongates and a medullary cavity forms: As the primary ossification center enlarges, osteoclasts break down the newly formed spongy bone and open up a medullary cavity in the center of the diaphysis. Ossification 'chases' cartilage formation along the length of the shaft. |
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Term
| Endochondral Ossification: Step 5 |
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Definition
| Epiphyses ossify. Secondary ossification centers appear in one or both epiphyses gain bony tissue. Secondary ossification reproduces primary ossification nearly. Differences: Spongy bone in interior is retained an no medullary cavity is formed. Hyaline cartilage remains at only 2 points: Articular cartilage and as epiphyseal plates |
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Term
| Endochondral Ossification: Summary |
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Definition
| Formation of Bone Collar, Cavitation, Invasion of the Periosteal Bud, Formation of the Medullary Cavity & appearance of secondary ossification centers, ossification of the epiphyses |
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Term
| Bone/Cartilage growth: Appositional |
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Definition
| Cells in the perichondrium secrete matrix against the external face of existing cartilage |
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Term
| Bone/Cartilage growth: Interstitial |
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Definition
| Lacunae-bound chondrocytes inside the cartilage divide and secrete new matrix, expanding the cartilage from within |
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Term
| Postnatal Bone Growth: Abbreviations |
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Definition
GTO: Growth zone, Transformation zone, Osteogenic zone
QMCO: Quiescent zone, Mitosis zone, Calcification Zone, Ossification zone |
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Term
| Functional Zones in Long Bone Growth: Growth Zone |
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Definition
| cartilage cells closer to the diaphysis undergo mitosis, pushing the epihysis away from the diaphysis. |
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Term
| Functional Zones in Long Bone Growth: Transformation Zone |
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Definition
| Older chondrocytes enlarge and die, matrix becomes calcified, matrix begins to deteriorate. |
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Term
| Functional Zones in Long Bone Growth: Osteogenic Zone |
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Definition
| New bone formation occurs. |
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Term
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Definition
| Bone is resorbed and added by appositional growth. Adjacent osteoblasts and osteoclasts deposit and resorb bone at periosteal and endosteal surfaces |
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Term
| Hormonal Regulation of Bone Growth: Infancy and Childhood |
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Definition
| Epiphyseal plate activity is stimulated by growth hormone |
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Term
| Hormonal Regulation of Bone Growth During Youth: Puberty |
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Definition
| Testosterone and Estrogens: Intially promote adolescent growth spurts, cause masculinization and feminization of specific parts of the skeleton, later induce epiphyseal plate closure, ending longitudinal bone growth. |
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Term
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Definition
| Occurs where bone is injured or added strength is needed. Requires a diet rich in protein, vitamins C, D, and A, calcium, phosphorus, magnesium, and manganese. Alkaline phosphate is essential for mineralization of bone |
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Term
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Definition
Sites of new matrix deposition are revealed by the:
Osteiod Seam: unmineralized band of bone matrix
Calcification front: abrupt transition zone between the osteoid seam and the older mineralized bone |
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Term
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Definition
| unmineralized band of bone matrix. part of Bone Deposition |
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Term
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Definition
| Abrupt transition zone between the osteiod seam and the older mineralized bone. Part of Bone Deposition |
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Term
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Definition
| Accomplished by osteoclasts. Resorption bays - grooves formed by osteoclasts as they break down bone matrix. Resorption involves osteolcast secretion of lysosomal enzyme that digest organic matrix, acids that convert calcium salts into soluble forms. DIssolved matrix is transcystoced across the osteoclast's cell where it is secreted into the interstitial fluid and then into the blood |
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Term
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Definition
| Grooves formed by osteoclasts as they break down bone matrix |
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Term
| Importance of Ionic Calcium |
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Definition
Transmission of nerve impulses
Muscle contraction
Blood coagulation
Secretion by glands and nerve cells
Cell division |
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Term
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Definition
Hormonal mechanism maintains calcium homeostasis in the blood
Mechanical and gravitational forces acting on the skeleton |
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Term
| Bone Remodeling Control: Hormonal |
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Definition
Rising Blood Ca2+ levels trigger the thyroid to release calcitonin. Calcitonin stimulates calcium salt deposit in bone.
Falling blood Ca2+ levels signal the parathyroid glands to release PTH (parathyroid hormone). PTH signals osteoclasts to degrade bone matrix and release Ca2+ into blood |
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Term
| Bone Fracture: Classification |
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Definition
Position of the bone ends after fracture
Completeness of the break
Orientation of the bone to the long axis
Skin penetration |
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Term
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Definition
Nondisplaced: Bone ends retain their normal position
Displaced: bone ends are out of normal alignment
Complete: bone is broken all the way through
Incomplete - bone is not broken all the way through
Linear - the fracture is parallel to the long axis of the bone
Transverse - the fracture is perpendicular to the long axis of the bone
Compound: Open bone end penetrates the skin
Simple: closed, bone end does not penetrate the skin |
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Term
| Bone Fractures: Common Types |
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Definition
Comminuted - bone fragments into 3 or more pieces, common in the elderly
Compression: Bone is crushed; common in porous bones
Depressed: broken bone portion pressed inward; typical skull fracture
Greenstick: incomplete fracture where one side of the bone breaks and the other side bends; common in children
Spiral: ragged break when bone is excessively twisted; common sports injury
Epiphyseal: epiphysis separates from diaphysis along epiphyseal line, occurs where cartilage cells are dying |
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Term
| Bone Fracture Healing: Step 1 |
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Definition
Hematoma Formation:
Torn blood vessels hemorrhage
A mass of clotted blood (hematoma) forms at the fracture site
SIte becomes swollen, painful, and inflamed |
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Term
| Bone Fracture Healing: Step 2 |
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Definition
| Fibrocartilaginous callus forms: Granulation tissue (soft callus) forms a few days after the fracture. Capillaries grow into the tissue and phagocytic cells begin clearing debris. |
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Term
| Bone Fracture Healing: Step 2: Fibrocartilaginous callus formation |
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Definition
Osteoblasts and fibroclasts migrate to the fracture and begin reconstructing the bone
Fibroblasts secrete collage fibers that connect broken bone ends
Osteoblasts begin forming spongy bone
Osteoblasts furthest from capillaries secrete an externally bulging cartilaginous matrix that later calcifies |
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Term
| Bone Fracture Healing: Step 3 |
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Definition
Bony Callus Formation: New bone trabeculae appear in the fibrocartilaginous callus.
Fibrocartilaginous callus converts into a bony (hard) callus.
Bone callus begins 3-4 weeks after injury, and continues until firm union is formed 2-3 months later |
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Term
| Bone Fracture Healing: Step 4 |
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Definition
Bone Remodeling:
Excess material on the bone shaft exterior and in the medullary cavity is removed.
Compact bone is laid down to reconstruct shaft walls |
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