Term
| The vast majority of the human skeleton is composed of this type of bone: |
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Definition
| Cortical (hard outer) bone |
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Term
| About 20% of the human skeleton is comprised of this type of bone: |
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Definition
| Trabecular (spongy inner) bone |
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Term
| Bone formation and resorption occurs in this type of bone: |
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Definition
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Term
| These bone cells help make bone: |
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Definition
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Term
| These bone cells are responsible for bone resorption: |
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Definition
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Term
| These cells are embedded in the bone and help regulate osteoblast and osteoclast activity: |
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Definition
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Term
| Bone is made mostly of this inorganic compound: |
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Definition
| Hydroxyapatite (Crystalline calcium phosphate salts) |
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Term
| The osteoid is a matrix consisting primarily of: |
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Definition
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Term
| This is a matrix consisting primarily of type I collagen fibers: |
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Definition
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Term
| These are mononuclear cells that are responsible for bone formation: |
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Definition
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Term
| Osteoids are produced by these cells: |
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Definition
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Term
| These cells are responsible for mineralization of the osteoid matrix: |
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Definition
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Term
| These are multinucleated bone-resorbing cells: |
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Definition
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Term
| Osteoblasts have how many nucleii? |
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Definition
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Term
| Osteoclasts are (mono/multi)-nucleated. |
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Definition
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Term
| These are star-shaped cells derived from the osteoblasts: |
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Definition
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Term
| Osteoblasts become embedded in the bony matrix and differentiate into: |
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Definition
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Term
| These tiny structures form networks between osteocytes via long processes that occupy tiny canals: |
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Definition
|
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Term
| The canaliculi function to: |
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Definition
| Exchange nutrients and waste |
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Term
| Osteocytes act as _______ by being actively involved in the maintenance of the bony matrix. |
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Definition
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Term
| Osteocytes' main function is to: |
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Definition
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Term
| Osteoblasts control this primary component of the bone matrix: |
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Definition
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Term
| Osteoblasts are responsible for collagen type I, as well as these other components of the matrix: |
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Definition
| Proteoglycan, osteocalcin, phosphoproteins |
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Term
| Osteoblasts utilize this substance to increase the local concentration of inorganic phosphates: |
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Definition
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Term
| Osteoblasts increase the local concentration of calcium through: |
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Definition
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Term
| Osteoclasts release this substance which breaks down collagen type I: |
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Definition
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Term
| Osteoclasts release these substances which break down proteins: |
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Definition
|
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Term
| Osteoclasts utilize these substances to break down hydroxyapaptite: |
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Definition
| Organic acids, lactic acid, carbonic acid, citric acid |
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Term
| This is the major hormone that regulates Ca++ levels: |
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Definition
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Term
| PTH stimulates this in the kidneys: |
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Definition
| Ca++ resorption and facilitates phosphate excretion |
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Term
| PTH's main action is elevating: |
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Definition
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Term
| Once daily exogenous PTH has this action: |
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Definition
| Stimulates bone formation |
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Term
| Exogenous PTH qday is used to treat: |
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Definition
| Osteoporosis and other osteopathologies |
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Term
| Exogenous calcitonin MOA: |
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Definition
|
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Term
| Exogenous calcitonin is used to treat: |
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Definition
| Osteoporosis and other osteopathologies |
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Term
| Endogenous secretion of PTH modulates _______ and stimulates ________ of calcium in the nephron. |
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Definition
| Bone resorption; tubular reabsorption |
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Term
| Bone resorption and tubular reabsorption of calcium in the nephrons have this effect on blood calcium levels: |
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Definition
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Term
| This vitamin enhances absorption of Ca++ from the GI tract: |
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Definition
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Term
| Approximately 25% of this type of bone is remodeled every year: |
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Definition
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Term
| Approximately 3% of this type of bone is remodeled each year: |
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Definition
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Term
| This hormone indirectly controls bone growth by stimulating the liver to secrete IGF-1, which is essential for growth and health: |
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Definition
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Term
| These cytokines are important for bone remodeling: |
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Definition
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Term
| PTH, shear stress, etc. cause osteoblast precursors to express this: |
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Definition
|
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Term
| RANKL binds to RANK receptors on: |
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Definition
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Term
| Binding of the RANKL and RANK receptor causes the maturation of: |
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Definition
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Term
| As mature osteoclasts resorb bone, matrix bound factors such as these are released: |
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Definition
| TGF-B, IGF-1, other growth factors and cytokines |
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Term
| Factors released from the maturation of osteoclasts stimulate the maturation of: |
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Definition
| Osteoblast precursors to osteoblasts |
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Term
| This hormone is a single polypeptide chain of 84 amino acids: |
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Definition
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Term
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Definition
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Term
| PTH release is inhibited by: |
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Definition
|
|
Term
| The main action of PTH is to: |
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Definition
|
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Term
| PTH induces the expression of _______, the osteoclast differentiation factor on the surface of osteoblasts. |
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Definition
|
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Term
| PTH increases osteoclast activity by: |
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Definition
| Promoting the differentiation of osteoclasts by binding to RANK |
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Term
| PTH increases osteoclast activity by: |
|
Definition
| Promoting the differentiation of osteoclasts by binding to RANK |
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Term
| Excessive amounts of PTH may cause: |
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Definition
|
|
Term
| Excessive amounts of PTH may cause: |
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Definition
|
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Term
| In the bones, PTH increases _____ activity, liberating PO4 and Ca2. |
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Definition
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Term
| PTH's action in the kidney: |
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Definition
| Facilitates PO4 excretion and Ca++ reabsorption; increases hydroxylation of vitamin D to calcitriol |
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Term
| Active vitamin D (calcitriol) acts on the intestine to: |
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Definition
| Increase absorption of Ca++ from the small intestine. |
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Term
| Vitamin D2 (ergocalciferol) comes from: |
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Definition
|
|
Term
| Vitamin D3 (cholecalciferol) is produced: |
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Definition
|
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Term
| Vitamin D regulates the Ca and PO4 levels in the blood by promoting: |
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Definition
| Absorption from foods in the small intestine; reabsorption of Ca in the kidneys |
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Term
| PTH secretion is inhibited by this fat soluble vitamin: |
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Definition
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Term
| High pharmacological concentrations of vitamin D promote: |
|
Definition
| Bone resorption by increasing osteoclast expression and activity |
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Term
| Vitamin D afftects the immune system by promoting: |
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Definition
| Immunosuppression and anti-tumor activity |
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Term
| The vitamin D precursor 7-dehydrocholesterol is converted to cholecalciferol by: |
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Definition
|
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Term
| PTH stimulates the expression of this enzyme, which converts 25-D to 1,25-dihydroxyD: |
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Definition
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Term
| People with end stage renal disease are unable to carry out this action, with can cause problems with PTH and calcium regulation: |
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Definition
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Term
| This hormone counteracts the actions of PTH: |
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Definition
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Term
| This hormone inhibits the actions of osteoclasts, decreases Ca absorption from the intestines, and decreases Ca resorption in the kidneys: |
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Definition
|
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Term
| Calcitonin binds directly to receptors on osteoclasts, inhibiting: |
|
Definition
| The resorptive activity of osteoclasts |
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Term
| Calcitonin is produced by these cells: |
|
Definition
| C Cells in the thyroid gland |
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Term
| Estrogens inhibit these things responsible for recruiting and activating osteoclasts: |
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Definition
| Cytokines produced by osteoblasts |
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Term
| Estrogens promote the synthesis of these: |
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Definition
| Decoy receptors -- OPG, IL-1R |
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Term
| Estrogen inhibits the apoptosis of: |
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Definition
| Osteoblasts and osteocytes |
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Term
| Estrogen stimulates osteoclast apoptosis driven by: |
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Definition
|
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Term
| Withdrawal of estrogen cau lead to this bone disease: |
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Definition
|
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Term
| Physiological concentrations of glucocorticoids are required for: |
|
Definition
| Osteoblast differentiation |
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Term
| Excessive pharmacologic concentrations of glucocorticoids cause these effects: |
|
Definition
| Inhibit bone formation by inhibiting osteoblast differentiation and activity; may stimulate osteoclast action leading to osteoporosis |
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Term
| This disease is characterized by reduction of bone mass with distortion of the micro architecture: |
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Definition
|
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Term
| The most common causes of osteoporosis are: |
|
Definition
| Postmenopausal deficiency of estrogen and age-related deterioration in bone homeostasis |
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Term
| Osteoporosis may occur secondary to: |
|
Definition
| Rheumatoid arthritis, excessive thyroxine, glucocorticoid administration |
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Term
| Treatment for osteoporosis includes: |
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Definition
| Anti-resorptive drugs; drugs that stimulate bone formation |
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Term
| Chronic kidney disease may cause secondary: |
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Definition
|
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Term
| This disease results from hyperparathyroidism and is characterized by decreased mineralization: |
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Definition
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Term
| This disease caused by secondary hyperparathyroidism is characterized by increased osteoclastic resorption with replacemtn by fibrous tissue: |
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Definition
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Term
| This hormone replacement therapy was once the most commonly prescribed drug for postmenopausal osteoporosis: |
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Definition
|
|
Term
| Estrogen does not increase bone formation, but: |
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Definition
| It does maintain bone mass |
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Term
| Estrogen is administered cycliclally with a _________ to reduce the risk of endometrial cancer. |
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Definition
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|
Term
| Adverse effects of estrogen hormone replacement therapy include: |
|
Definition
| Vaginal bleeding, breast tenderness, increased risk for DVT and breast cancer |
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Term
| Selective Estrogen Receptor Modulators recruit tissue-selective: |
|
Definition
| Transcriptional co-repressors or co-activators |
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Term
| Raloxifene is an estrogen ___ in bone, but an estrogen ____ in the endometrium and breast. |
|
Definition
| Agonist in bone; antagonist in endometrium and breast |
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Term
| Reloxifene is used to treat _____ and may also have these benefits: |
|
Definition
| Osteoporosis; reduce the risk of breast cancer; lowers LDL |
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Term
| Raloxifene causes an increased risk of: |
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Definition
|
|
Term
| This is the most widely used class of antiresorptive drugs: |
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Definition
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|
Term
| Bisphosphonates tend to concentrate in the bone, forming complexes with: |
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Definition
|
|
Term
| Bisphosphonates are incorporated into: |
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Definition
|
|
Term
| Bisphosphonates are released during: |
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Definition
|
|
Term
| Released bisphosphonates are taken up by: |
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Definition
|
|
Term
| Amino-bisphosphonate complexes inhibit a step in the: |
|
Definition
| Mevalonate pathway, which is important for protein prenylation |
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Term
| Disruption of the mevalonate pathway leads to: |
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Definition
|
|
Term
| Disruption of protein prenylation in osteoclasts eventually causes: |
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Definition
|
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Term
| Major side effects of bisphosphonates include: |
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Definition
|
|
Term
| Bisphosphonates are used clinically to treat: |
|
Definition
| Osteoporosis, hypercalcemia of malignancy (tumors product PTHrP), and Paget's disease |
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|
Term
| The mevalonate pathway changes: |
|
Definition
| Acetyl CoA to cholesterol |
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Term
| The backbone of bisphosphonate structures is essentially: |
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Definition
|
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Term
| Bisphosphonates with amino groups are metbolized in the body; they look like and compete with this molecule in osteoclast cells causing apoptosis: |
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Definition
|
|
Term
| Calcitonin activates this type of receptor: |
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Definition
|
|
Term
| Calcitonin activates a GPCR on ______, thereby______. |
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Definition
| Calcitonin activates a GPCR on osteoclasts, thereby decreasing the resorptive activity |
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|
Term
| Calcitonin is used clinically: |
|
Definition
| To prevent bone loss and fractures and increase bone density in patients with osteoporosis. |
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|
Term
| Fluoride acts as a ____ for osteoblasts. |
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Definition
|
|
Term
| High concentrations of fluoride increases: |
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Definition
|
|
Term
| Use of fluoride leads to the conversion of: |
|
Definition
| Hydroxyapatide to fluoroapatite, which is denser but more brittle |
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|
Term
| Endogenous PTH at high concentrations stimulates: |
|
Definition
|
|
Term
| PTH subcutaneous injection QD causes: |
|
Definition
| Decreased osteoclast activity --> stimulates bone formation |
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|
Term
| Intermitant stimulation of bone cells by PTH: |
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Definition
| Increases bone remodeling, but with more new bone formed than old bone resorbed |
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|
Term
| PTH acutely promotes osteoblast: |
|
Definition
| Differentiation and activity |
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