Term
| Osteogenesis (ossification) |
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Definition
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Term
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Definition
1.bone formation-begins in the 2nd month of development
2. postnatal bone growth- until early adulthood
3. bone remodeling and repair- lifelong |
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Term
| Two types of Ossification |
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Definition
1. Intramembranous ossification
2. Endochondral ossification |
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Term
| Intramembranous ossification |
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Definition
| membrane bone develops from fibrous membrane; forms flat bones (calvicle and cranial) |
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Term
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Definition
| Cartilage (endochondral) bone forms by replacing hyaline cartilage; forms most of the rest of the skeleton |
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Term
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Definition
1. ossification centers appear in the fibrous connective tissue membrane
2. Bone matrix (osteoid) is secreted within the fibrous membrane and calcifies.
3. Woven bone and periosteum form
4. lamellar bone replaces woven bone, just deep to the periosteum. Red marrow appears.
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Term
| Stages of Endochondral ossification |
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Definition
1. bone collar forms around hyaline cartilage
2. cartilage in center of the diaphysis calcifies and then develops cavities.
3. the periosteal bud inavades the internal cavities and spongy bone begins to form.
4. the diaphysis elonagtes and a meddullary cavity forms as ossification continues.
5. the epiphyses ossify. When completed, hyaline cartilages remains only in epiphyseal plates and articular cartilages. |
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Term
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Definition
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Term
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Definition
| thickness and remodeling of all bones by osteoblasts and osteoclasts on bone surfaces |
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Term
| Epiphyseal plate cartilages functional zones |
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Definition
1. proliferation
2. hypertrophic
3. calcification
4. ossification (osteogenic) |
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Term
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Definition
| cartilage cells undergo mitosis |
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Term
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Definition
| older cartilage cells enlarge |
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Term
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Definition
| matrix becomes calcified; cartilages cells die; matrix begins deteriorating |
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Term
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Definition
| new bone formation is occuring |
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Term
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Definition
| stimulates epiphyseal plate activity |
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Term
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Definition
| modulates activity of growth hormone |
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Term
| Testosterone and estrogen (at puberty) |
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Definition
| promotes adolescent growth spurts; end growth by inducing epiphyseal plate closure |
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Term
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Definition
| occurs where bone is injured or added strength is needed |
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Term
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Definition
| a diet rich in protein; vitamins C,D, and A;calcium; phosphorus;magnesium; and manganese |
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Term
| New matrix deposit are revealed by the |
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Definition
1. Osteiod seam-unmieralized band of matrix
2. calcification front- abrupt transition zone between the osteoid seam and the older mineralized bone |
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Term
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Definition
| Lysosomal enzymes (digest organic matrix); acids (convert calcium salts into soluble forms) |
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Term
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Definition
| dissolved matrix is transcytosed across osteoclast, enters interstitial fluid and then blood |
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Term
What contols continual remodeling of bone?
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Definition
| hormonal mechanisms that maintain calcium homeostasis in the blood; mechanical and gravitational forces |
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Term
| Calcium in hormonal control of blood Ca is necessary for |
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Definition
1. transmission of nerve impulses
2. muscle contraction
3. blood coagulation
4. secretion by glands and nerve cells
5. cell division |
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Term
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Definition
| a bone grows or remodels in response to forces or demands placed upon it |
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Term
| Obsevations supporting Wolff's law |
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Definition
1. handedness results in bone of one upper limb being thicker and stronger
2. curved bones are thickest where they are most likely to buckle
3. trabeculae form along lines of stress
4. Trabeculae form along lines of stress
5. large, bony projections occur where heavy, active muscles attach |
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Term
| bone fractures classifications |
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Definition
1. position of bone ends after fracture
2. completeness of the break
3. orientation of the break to the long axis of the bone
4. whether or not the bone ends penetrate the skin |
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Term
| Position of bone ends after fracture |
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Definition
1. nondisplaced- ends retain normal position
2. displaced- ends out of normal alignment |
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Term
| Completeness of the break |
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Definition
1. complete- broken all the way through
2. Incomplete- not broken all the way through |
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Term
| Orientaaion of the breaak to the long axis of the bone |
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Definition
1. Linear- parallel to long axis of the bone
2. transverse- perpendicular to the long axis of the bone |
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Term
| Whether or not the bone ends penetrate the skin |
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Definition
1. compound (open)- bone ends penetrate the skin
2. simple (closed)- bon ends do not penetrate the skin |
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Term
| Common types of fractures |
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Definition
1. location
2. external appearance
3. nature of the break |
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Term
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Definition
| bone fragments into 3 or more pieces |
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Term
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Definition
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Term
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Definition
| ragged break occurs when excessive twisting forces are applied to a bone |
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Term
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Definition
| epiphysis seperate from the diaphysis along the epiphyseal plate |
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Term
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Definition
| broken bone portion is pressed inward |
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Term
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Definition
| bone breaks incompletely, much in the way a green twig breaks. only one side of the shaft breaks, the other side bends |
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Term
| Stages in the healing of a bone fracture |
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Definition
1. Hematoma forms
2. Fibrocartilaginous callus forms
3. Bony callus formation
4. Bone remodeling
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Term
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Definition
| torn blood vessels hemorrhage, clot forms, site becomes swollen, painful, and inflamed |
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Term
| Fibrocartilaginous callus forms |
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Definition
1. phagocytic cells clear debris
2. osteoblasts begins forming spongy bone in 1 week
3. fibroblasts secrete collagen fibers to connect bone ends |
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Term
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Definition
1. new trabeculae form a bony(hard) callus
2. bony callus formation continues until firm union is formed in ~2 months |
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Term
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Definition
1. in response to mechanical stressors over several months
2. final structure resembles original |
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Term
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Definition
calcium salts not deposited, cause bowed legs and other bone deformities ( childhood disease)
caused: vitamin D deficiency or insffiecient dietary calcium |
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Term
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Definition
| loss of one mass; spongy bone of spine and neck of femur become most susceptible to fracture |
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Term
| Risk factors for osteoporosis |
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Definition
| lack of estrogen, calcium or vitmain D; petite body form; immobility; low levels of TSH; diabetes mellitus |
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Term
| Osteoporosis: treatment and prevention |
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Definition
| calcium, vitamin D, and fluoride supplements, weight-bearing exercise; hormone (estrogen) slows bone loss; some drugs |
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Term
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Definition
| excessive and haphazard bone formation and breakdown, usually in spine, pelvis, femur, or skull |
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Term
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Definition
| has a very high ratio of spongy to compact bone and reduced minerlization; has no cause |
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Term
| Paget's disease treatment |
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Definition
| calcitonin and biphosphonates |
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