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35 Cards in this Set
- Front
- Back
neurological manifestations of E deficiency?
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absent tendon reflexes
ataxia loss of position, pain and vibration sense |
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How is Vit K involved w/blood clotting?
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it is a cofactor for an enzyme that carboxylates glutamate. This is neccesary for clotting factors 7, 9 and 10 to work
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How does K favor calcification of bone proteins?
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osteocalcin is a protein secreted by osteoblasts. it binds with calcium after it has been carboxylated (and K helps with this carboxylation too)
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how can K inhibit resorption of calcium from bone?
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it inhibits expression of an osteoclast differentiation factor (RANK)
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Since K is widely available in western diets, why do deficiencies develop? (4)
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fat malabsorption disorder
destruction of endogenous flora that makes K (think tetracycline) neonatal period (small liver=low stores of K, flora hasn't developed yet, not much K in breast milk) diffuse liver disease (jacks w/K dependent enzymes even if there's plenty of K |
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functions of thiamine?
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helps make ATP
part of pentose phosphate pathway (alternative to glycolysis) maintains nerve conduction |
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dry beriberi - def and aka?
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a polyneuropathy (w/myelin degeneration) caused by thiamine deficiency.
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wet beriberi - def and aka?
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a cardiovascular syndrome caused by thiamine deficiency. Characterized by edema and high-output cardiac failure
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Wernicke encephalopathy - when does it usually develop?
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after the other two syndromes (dry followed by wet beriberi) of thiamine deficiency
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Korsakoff psychosis - symptoms?
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retrograde amnesia
can't acquire new information |
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what part of the brain does Wernicke-Korsakoff affect?
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area of the fourth ventricle: hypothalamus, mamillary bodies, optic chiasm, etc.
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pellagra - def?
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niacin deficiency syndrome
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who usually gets pellagra in the US?
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alcoholics, HIV positive pts, and others w/seriously debilitating diseases (like people on isoniazid)
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what drug is assoc w/pellagra?
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isoniazid
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what are the three Ds of pellagra?
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dermatitis (symmetric and on exposed areas of body)
diarrhea (due to atrophy of columnar epithelium dementia (due to degeneration of neurons in the brain) |
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what are the three drugs listed in Robbins as pyridoxine (B6) antagonists?
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isoniazid
estrogens penicillamine |
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why are alcoholics likely to develop pyridoxine (B6) deficiency?
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because acetaldehyde (a metabolite of alcohol) enhances pyridoxine degradation
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what is the important thing to know about homocysteine?
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it's a risk factor for atherosclerosis
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two things characteristic of scurvy?
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bone disease in growing children
hemmorhages and healing deficits in kids and adults |
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what is the function of vitamin C?
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activation of prolyl and lysyl, which hydroxylate procollagen. This means that there isn't enough strong collagen to hold blood vessels together, and you get the hemmorhaging of scurvy
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Two ways C acts as an antioxidant?
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directly, scavenging for free radicals
indirectly by regenerating Vit E to it's active form |
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what is a characteristic sign of severe scurvy?
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perifollicular, hyperkeratotic papular rash, with a ring of hemhorage around it.
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deficiency of what two things results in megaloblastic anemia?
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Folate and B12
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Why are folate and pyridoxine (B6) both needed at high levels during pregnancy?
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because rapidly dividing cells require these two things
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Why take folic acid supplements if you are trying to get pregnant?
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because neural tube defects from folate deficiency happen in the first couple of weeks after conception
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how can folate be stripped from folate-rich foods?
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heat: it is depleted in cooked and processed foods
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What common things interfere w/folate metabolism? (4)
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alcohol
cigarettes oral contraceptives anti-convulsives |
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combined folate and B12 deficiency is linked to what serious illness?
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colon cancer
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acrodermatitis enteropathica - def
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distinctive rash around mouth, eyes, nose, anus - assoc w/zinc deficiency
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When should you suspect zinc deficiency?
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when you see a rash that could be acrodermatitis enteropathica, combined w/growth retardation or infertility
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Keshan disease - def and symptoms?
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this is selenium deficiency, presents as congestive cardiomyopathy
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what are the organs and substances they secrete that make up the afferent system of the lipostat?
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adipose tissue (leptin)
pancreas (insulin) stomach (grehlin) |
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where is the central processing unit of the lipostat?
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hypothalamus
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what is the net effect of a high level of Leptin in the blood?
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reduced food intake
increased energy expenditure |
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What effect does beta-carotene have on cancer prevention?
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reverses squamous metaplasia and preneoplastic lesions in the respiratory tract
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