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19 Cards in this Set
- Front
- Back
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What are the main controlling factors in magnesium homeostasis?
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gastrointestinal absorption and renal excretion
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Where is magnesium absorbed primarily?
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in the small intestine
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How is magnesium absorbed?
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through a saturable transport system and passive diffusion
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What is the relationship between calcium and magnesium in the gut?
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High calcium intake may decrease magnesium absorption, low magnesium intake may increase calcium
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List some factors inhibiting the absorption of magnesium
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alcohol
fibre low protein intake sodium high dose zinc |
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List some factors enhancing the absorption of magnesium
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PTH
Glucocorticoids Vitamin D |
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How is Magnesium transported through the body?
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via carrier-mediated transport systems
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What are the tissues with the highest magnesium concentration?
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brain, heart, liver, kidney
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What are two major differences of magnesium
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1. no hormonal modulation of urinary magnesium excretion occurs
2. bone does not readily exchange with circulating magnesium in the extracellular fluid |
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What is intracellular magnesium bound to?
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ATP, phosphocreatine or phospholipids of carious cell membranes such as nucleotides
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Increased magnesium excretion occurs with:
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hypermagnesaemia
hypercalciuria alcoholism caffeine |
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Decreased magnesium excretion occurs with:
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hypomagnesaemia
calcitronin glucagon |
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What are the primary functions of magnesium?
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energy production
synthesis of essential biomolecules cell signalling cell migration |
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What are the mechanisms of action of magnesium
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magnesium binds with functional groups such as phosphates, carboxylates and hydroxyls to:
1. form a complex with a substance 2. bind and interact directly with an enzyme |
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T/F Magnesium plays an essential role in the function of the cell membrane sodium-potassium ATPase pump
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true
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What is phosphorylation?
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the addition of a phosphate to one of the amino acid side chains of a protein.
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Define ataxia
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failure of muscle coordination, irregularity of muscular action
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List some rich nutritional sources of magnesium
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chlorophyll, green leafy vegetables, unrefined grains and nuts
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When is magnesium contraindicated?
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in renal insufficiency and heart block
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