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125 Cards in this Set
- Front
- Back
Dense irregular connective tissue that surrounds skeletal cartilage and resists outward expansion |
perichondrium |
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What are the three types of skeletal cartilage? |
hyaline, elastic, fibrocartilage |
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Does skeletal cartilage contain blood vessels or nerves? |
No |
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A skeletal cartilage that provides support, flexibility, and resilience; most abundant |
hyaline |
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Where is hyaline cartilage found? |
articular: ends of long bones costal: connects ribs to sternum respiratory: makes up larynx, reinforces air passages nasal: supports the nose |
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A skeletal cartilage similar to hyaline cartilage but contains elastic fibers |
elastic cartilage |
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Where is elastic cartilage found? |
external ear and epiglottis |
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A skeletal cartilage that is highly compressed with great tensile strength; contains collagen fibers |
fibrocartilage |
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Where is fibrocartilage found? |
menisci of knee and in intervertebral discs |
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When cells in the perichondrium secrete matrix against the external face of existing cartilage |
appositional growth |
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When lacunae-bound chondrocytes inside the cartilage divide and secrete new matrix, expanding the cartilage from within |
interstitial growth |
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Calcification of cartilage occurs when? |
during normal bone growth during old age |
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What is included in the axial skeleton? |
skull, vertebral column, rib cage |
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What is included in the appendicular skeleton? |
bones of the upper and lower libs, shoulder, hip |
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Bones that are longer than they are wide |
long bones |
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Bones from within tendons or cube-shapedbones found within the wrist and ankle |
short bones |
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Bones that are thin, flattened, and a bit curved |
flat bones |
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Bones with complicated shapes |
irregular bones |
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What are the five functions of bone? |
1. support 2. protection 3. movement - act as levers for muscles 4. mineral storage - especially Ca and P 5. blood cell formation |
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Rounded projection on a bone |
tuberosity |
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A narrow, prominent ridge of bone |
crest |
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A large, blunt, irregular surface on a bone |
trochanter |
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A narrow ridge of bone |
line |
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A small rounded projection on bone |
tubercle |
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A raised area above a condyle on bone |
epicondyle |
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A sharp, slender projection on a bone |
spine |
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Any bone prominence |
process |
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A bony expansion of the bone carried on a narrow neck |
head |
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A smooth, nearly flat articular surface on a bone |
facet |
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A rounded articular projection on a bone |
condyle |
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An armlike bar of bone |
ramus |
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A canal-like passageway on a bone |
meatus |
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A cavity within a bone |
sinus |
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A shallow, basin-like depression on a bone |
fossa |
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A furrow on a bone |
groove |
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A narrow, slit-like opening on a bone |
fissure |
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A round or oval opening through a bone |
foramen |
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The dense outer layer of bone |
compact bone |
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The honeycomb of trabeculae filled with yellow bone marrow |
spongy bone |
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A tubular shaft that forms the axis of long bones; composed of compact bone surrounding a medullary cavity containing yellow bone marrow |
diaphysis |
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Where the growth plate lies; found between the diaphysis and epiphysis |
metaphysis |
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The expanded ends of long bones; exterior is compact while the interior is spongy bone; joint surface is covered with hyaline cartilage |
epiphysis |
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Separates the diaphysis and epiphysis |
epiphyseal line |
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A double-layered protective membrane that surrounds bones |
periosteum |
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The outer fibrous layer of the periosteum is ____________ and the inner osteogenic layer is compose of ____________. |
dense regular connective tissue osteoblasts and osteoclasts |
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The periosteum is richly supplied with ______, ______, and __________ which enter the bone via _____________. It's secured to underlying bone by __________. |
nerve fibers blood lymphatic vessels nutrient foramina Sharpey's fibers |
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A delicate membrane covering the internal surfaces of bone |
endosteum |
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What is different about short/irregular/flat bones vs. long bones? |
1. they are made up of periosteum-covered compact bone on the outside and endosteum-covered spongy bone (diploe) on the inside 2. they have no diaphysis or epiphysis 3. they contain bone marrow between the trabeculae |
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Where is hematopoietic tissue found in infants? |
in the medullary cavity and all areas of spongy bones |
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Where is hematopoietic tissue found in adults? |
in the diploe of flat bones and the head of the femur and humerus |
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What is the structural unit of compact bone? |
Haversian system or osteon |
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Weight-bearing, column-like matrix tubes composed mainly of collagen |
lamella |
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Central channel containing blood vessels or nerves |
Haversian/central canal |
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Channels lying are right angles to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian canal |
Volkmann's canals |
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mature bone cells |
osteocytes |
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small cavities in bone that contain osteocytes |
lacunae |
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hair-like canals that connect lacunae to each other and the central canal |
canalicuni |
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bone-forming cells |
osteoblasts |
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large cells that reabsorb or break down bone matrix |
osteoclasts |
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unmineralized bone matrix composed of proteoglycans, glycoproteins, and collagen |
osteoid |
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mineral salts |
hydroxyapatites |
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Hydroxyapetites make up ____% of bone by mass and are composed of mainly _________. They are responsible for the bone's ________ and ________. |
65 calcium phosphates hardness resistance to compression |
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The process of bone tissue formation that leads to formation of bony skeleton in embryos, bone growth until early adulthood, and bone thickness, remodeling and repair |
osteogenesis and ossification |
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The formation of bony skeleton begins at week ___ of embryo development. |
8 |
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When bone develops from a fibrous membrane via mesenchymal cells; forms most of flat bones of skull and clavicles |
intramembranous ossification |
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When bone forms by replacing hyaline cartilage |
endochondral ossification |
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What are the stages of intramembranous ossification? |
1. An ossification center appears in the fibrous connective tissue membrane from locally differentiated mesenchymal cells. 2. Bone matrix (osteoid) is secreted within membrane via osteoblasts. 3. Osteoid is mineralized within a few days, trapped osteoblasts become osteocytes. 3. Woven bone and periosteum form - vascularized mesenchyme condenses on the external face of the woven bone. 4. Bone collar of compact bone forms, and red marrow appears |
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Endochondral ossification begins in the _____ month of development. It uses ___________ "bones" as models for bone construction. It requires the _______________ prior to ossification. |
2nd hyaline cartilage breakdown of hyaline cartilage |
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What are the stages of endochondral ossification? |
1. Formation of bone collar 2. Cavitation of hyaline cartilage 3. Invasion of internal cavities by the periosteal bud, and spongy bone formation 4. Formation of the medullary cavity; appearance of secondary ossification centers in the epiphysis 5. Ossification of the epiphysis, with hyaline cartilage remaining only in the epiphyseal plates |
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Cartilage on the side of the epiphyseal plate closest to the epiphysis is relatively ______. |
inactive |
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Cartilage abutting the shaft of the bone organizes into a pattern that _____________. |
allows fast, efficient growth. |
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The zone in which cartilage cells undergo mitosis, pushing the epiphysis away from the diaphysis |
growth zone |
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The zone where older cells enlarge, the matrix becomes calcified, cartilage cells die, and the matrix begins to deteriorate |
transformation (or hypertrophic and calcification) zone |
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The zone where new bone formation occurs |
osteogenic zone |
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cartilage continually grows and is replaced by bone |
growth in length |
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bone is reabsorbed and added by appositional growth |
remodeling |
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During childhood and infancy, epiphyseal plate activity is stimulated by _____. |
growth hormone |
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What are the roles of testosterone and estrogens in bone growth? |
During puberty: 1. promote growth spurts 2. cause masculinization and feminization of specific parts of the skeleton 3. later induce the epiphyseal plate closure, ending growth |
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Adjacent osteoblasts and osteoclasts that deposit and reabsorb bone at periosteal and endosteal surfaces |
remodeling units |
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Bone deposition occurs when bone is _____ or added _____ is needed. It requires a diet rich in ______, vitamins __, __, and __, _____, _____, magnesium, and manganese. |
injured strength protein C D A calcium phospherus |
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_____________ is essential for mineralization of bone. |
alkaline phosphatase |
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Sites of new matrix deposition are revealed by ______ and _______. |
osteoid seam and calcification front |
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unmineralized band of bone matrix |
osteoid seam |
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abrupt transition zone between the osteoid seam and the older mineralized bone |
calcification front |
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Bone reabsorption is accomplished by ______. |
osteoclasts |
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Grooves formed by osteoclasts as they break down bone matrix |
reabsorption bays |
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Reabsorption includes osteoclast secretion of ________ that digest organic matrix and ______ that convert calcium salts into soluble forms. |
lysosomal enzymes acids |
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dissolved matrix is transcytosed across the osteoclast's cell where it is secreted into the interstitial fluid and then into the blood |
bone reabsorption |
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Calcium is necessary for which five things? |
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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Which two control loops regulate bone remodeling? |
1. hormonal mechanism that maintains calcium homeostasis in the blood 2. mechanical and gravitational forces acting on the skeleton |
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What are the steps in the hormonal regulation of bone remodeling? |
1. rising blood calcium levels trigger the thyroid to release calcitonin 2. calcitonin stimulates calcium salt deposit in bone 3. falling calcium levels signal the parathyroid glands to release PTH 4. PTH signals osteoclasts to degrade bone matrix and release calcium into the blood |
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The ________ gland makes PTH. |
parathyroid |
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A bone grow or remodels in response to the forces or demands placed upon it |
Wolff's law |
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What observations support Wolff's law? |
1. long bones are thickest midway along the shaft (where bending stress is greatest) 2. curved bones are thickest where they are most likely to buckle |
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What happens in response to mechanical stress? |
1. trabeculae form along lines of stress 2. large, bony projections occur where heavy, active muscles attach |
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What four things are bone fractures classified by? |
1. the position of bone ends after fracture 2. the completeness of the break 3. the orientation of the bone to the long axis 4. whether or not the bone's ends penetrate the skin |
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A type of fracture where bone ends retain their normal position |
nondisplaced |
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A type of fracture where bone ends are out of normal alignment |
displaced |
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A type of fracture where bone is broken all the way through |
complete |
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A type of fracture where bone is not broken all the way through |
incomplete |
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A type of fracture where the fracture is parallel to the long axis of the bone |
linear |
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A type of fracture where the fracture is perpendicular to the long axis of the bone |
transverse |
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A type of fracture where bone ends penetrate the skin |
compound (open) |
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A type of fracture where bone ends do not penetrate the skin |
simple (closed) |
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A type of fracture where bone fragments into three or more pieces; common in elderly |
comminuted |
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A type of fracture where there is a ragged break when bone is excessively twisted; common sports injury |
spiral |
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A type of fracture where broken bone portion is pressed inward; typical skull fracture |
depressed |
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A type of fracture where bone is crushed; common in porous bones |
compression |
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A type of fracture where the epiphysis separates from the diaphysis along the epiphyseal line; occurs where cartilage cells are dying |
epiphyseal |
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A type of incomplete fracture where one side of the bone breaks and the other side bends; common in children |
greenstick |
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What happens in the "hematoma formation" stage of healing a bone fracture? |
-torn blood vessels hemorrhage -a mass of clotted blood forms -site becomes swollen, painful, and inflamed |
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What happens in the "fibrocartilaginous callus formation" stage of healing a bone fracture? |
-fibrocartilaginous callus forms -granulation tissue (soft callus) forms a few days later -capillaries grow into the tissue and phagocytic cells begin cleaning debris |
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How does the fibrocartilaginous callus form? |
1. osteoblasts and fibroblasts migrate to the fracture and begin reconstructing the bone 2. fibroblasts secrete collagen fibers that connect broken bone ends 3. osteoblasts begin forming spongy bone 4. osteoblasts furthest from capillaries secrete an externally bulging cartilaginous matrix that later calcifies |
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What happens in the "bony callus formation" stage of healing a bone fracture? |
-new bone trabeculae appear in the fibrocartilaginous callus -fibrocartilaginous callus converts into a bony callus -bone callus begins 3-4 weeks after injury, and continues until firm union is formed 2-3 months later |
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What happens in the "bone remodeling" stage of healing a bone fracture? |
-excess material on the bone shaft exterior and in the medullary canal is removed -compact bone is laid down to reconstruct shaft walls |
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When bones are inadequately mineralized causing softened, weakened bones; main symptoms is pain when weight is put on the affected bone |
osteomalacia |
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What is osteomalacia caused by? |
insufficient calcium in the diet or vitamin D deficiency |
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When bones of children are inadequately mineralized causing softened, weakened bones; characterized by bowed legs and deformities of the pelvis, skull, and rib cage |
Rickets |
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What is Rickets caused by? |
insufficient calcium in the diet or vitamin D deficiency |
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A group of diseases in which bone reabsorption outpaces bone deposit; spongy bone of the spine is most vulnerable; most often occurs in menopausal women; bones become so fragile that sneezing or stepping off a curb can cause fractures |
osteoporosis |
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How is osteoporosis treated? |
-calcium and vitamin D supplements -increased weight-bearing exercise -hormone (estrogen) replacement therapy slows bone loss -natural progesterone cream promotes new bone growth -statins increase bone mineral density |
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A disease characterized by excessive bone formation and break down; bone with an excessively high ratio of woven to compact bone is formed; reduced mineralization causes spotty weakening of bone |
Paget's disease |
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In Paget's disease, ______ activity wanes while ______ activity continues to work. |
osteoclast osteoblast |
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Where is Paget's disease usually localized? |
spine, pelvis, femur, skull |
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What is the cause of Paget's disease and what are the available treatments? |
Cause: unknown Treatments: drugs (Didronate and Fosamax) |