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53 Cards in this Set
- Front
- Back
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what endocrine disorder is diagnostic of anorexia nervosa?
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amennorhea
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how does amennorhea happen in anorexia nervosa?
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No GnRH secreted, and so no LH or FSH
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Thyroid changes in anorexia nerv? (3)
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decreased thyroid hormone release leads:
feeling cold bradycardia constipation |
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lanugo - def?
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increased body hair that is fine and pale - see this w/anorexia
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Why is bone density decreased w/anorexia?
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low estrogen levels, so you lose bone density just like in menopause
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why are anorexics at risk for arrythmias and sudden death?
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hypokalemia
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Three big complications of bulemia due to constant vomiting?
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hypokalemia (arrythmias)
aspiration of stomach contents esophageal and cardiac rupture |
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which vitamins are you likely to be deficient in if you have poor fat absorption disorder of the gut?
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A D E K
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primary vs secondary vitamin deficiency?
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primary - means you aren't eating enough of the vitamin
secondary - something is going wrong inside you and you aren't getting the benefit of the vitamin |
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MCC of Vitamin A toxicity?
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drugs used to treat acne and leukemia
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why are anorexics at risk for arrythmias and sudden death?
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hypokalemia
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Three big complications of bulemia due to constant vomiting?
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hypokalemia (arrythmias)
aspiration of stomach contents esophageal and cardiac rupture |
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which vitamins are you likely to be deficient in if you have poor fat absorption disorder of the gut?
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A D E K
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primary vs secondary vitamin deficiency?
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primary - means you aren't eating enough of the vitamin
secondary - something is going wrong inside you and you aren't getting the benefit of the vitamin |
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MCC of Vitamin A toxicity? what does it lead to?
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drugs used to treat acne and leukemia
A toxicity is teratogenic |
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Follicular hyperkeratosis - def?
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Vit A disorder where sebaceous glands are occluded and you get squamous metaplasia
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Keratomalacia - def?
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Vit A disorder where you get softening of the cornea
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Xeropthalmia - def
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Vit A disorder where you get dry eyes caused by squamous metaplasia of conjunctiva and tear ducts
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Most basic thing that A deficiency causes?
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night blindness
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Vit E - aka and it's one and only function?
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aka alpha tocopherol
function: antioxidant |
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Vit E deficiency causes:
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hemolytic anemia & thrombocytosis
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retinol vs retinol ester
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retinol is the transport form of Vit A (the most important kind)
retinol ester is the storage form |
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beta-carotene - def?
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a provitamin (comes from leafy green veggies) that can be metabolized in vivo to Vitamin A
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How is vitamin A stored?
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ingested as esters or beta carotene
moved to the liver in chylomicrons esterified and stored in the liver |
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How is retinoic acid different from retinol?
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it is absorbed unchanged from the blood (doesn't need to go to the liver or anything) and it doesn't help vision.
Retinoic acid helps epithelial differentiation and growth |
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how does retinol go from the storage place in the liver to cells that need it?
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liver makes a retinol binding protein.
protein/retinol complex is released in blood complex binds to cells that have a receptor for the binding protein |
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3 broad functions of Vit A in humans?
two less important functions? |
maintain normal vision in reduced light
differentiation of epithelial cells enhance immunity to infection photoprotective & antioxidant |
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rhodopsin - def?
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the very light sensitive form of vitamin A found in rods
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how is rhodopsin made?
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retinol -> all-trans-retinal -> 11-cis-retinal -> interaction w/opsin to form rhodopsin
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what happens to mucus-secreting epitelium when A is deficient?
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squamous metaplasia and differentiation to a keratinized epithelium
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14-hydroxyretinol - def?
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a metabolite of vitamin A that stimulates the immune system
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mech of reduced availability of Vitamin A to tissues during infection?
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retinol binding protein formation is reduced, meaning retinol can't be transported to tissues
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why do you get dry eyes w/vit A deficiency?
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because the normal lacrimal and mucus secreting epithelium of the eyes is being replaced by keratinized epithelium
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bitot spots - def
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buildup of keratin debris in opaque spots on the cornea (caused by vitamin A deficiency)
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what is squamous metaplasia? where does it happen in Vit A deficiency?
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normal epithelial cells being replaced by keratinizing squamous cells (in the case of Vit A deficiency you see this in the respiratory tract and urinary tract in addition to the eyes)
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what problem does squamous metaplasia cause in the urinary tract?
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renal and urinary bladder stones
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what problem does squamous metaplasia cause in the respiratory tract?
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the loss of mucociliary epithelium predisposes to secondary pulmonary infections
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symptoms of acute vit a toxicity? (3)
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simulates a brain tumor:
headache vomiting papilledema |
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symptoms of chronic vit a toxicity?
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weight loss
bone and joint pain hepatomegaly |
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contraindication of synthetic retinoids?
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teratogenicity
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mechanism of Vitamin A causing bone resorption?
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at toxic levels it stims osteoclast activity, esp a problem with old people
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broad function of Vitamin D
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maintain blood calcium levels
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insufficient calcium in ECF causes what?
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continuous excitation of muscles (hypocalcemic tetany)
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4 steps in Vit D metabolism
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Vit D is absorbed into the blood
binds to D-binding protein for transport to the liver Conversion to 25-hydroxyvitamin D (25 OH D) Conversion from 25 OH D to 1,25 OH D (this happens in the kidney |
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How is metabolism of D regulated? (3)
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negative feedback loop triggered by 1,25 OH D levels and affecting alpha hydroxylase, the enzyme that makes 25 OH D
Hypocalcemia stims PTH which activates alpha hydroxylase hypophophatemia directly activates alpha hydroxylase |
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Three specific functions of active Vit D
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stims intestinal absorption of Ca and P
Helps PTH pull calcium from bone Stims PTH-dependent reabsorption of Ca from DCT of kidney |
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Hypocalcemia leading to increased PTH does what to the kidneys?
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activates renal alpha hydroxylase 1 to increase active vit D levels and gut Ca absorption
decreases renal calcium excretion increases renal phosphate excretion |
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two most notable deformities of a kid w/rickets?
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bowing of the legs
excessive lumbar lordosis |
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osteomalacia - mech and what bones especially affected?
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new osteoid matrix made by osteoblasts isn't mineralized into bone properly. This makes the bones weak, especially the vertebral bodies and femoral neck
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how does vitamin E help protect cell membranes
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terminates lipid peroxidation chain reactions that are caused by free radicals
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how is selenium kind of a counterpart of Vitamin E in protecting cell membranes?
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it neutralizes free radicals before they can start the lipid peroxidation chain reactions that Vit E is good at terminating
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two things that will be hurt by free radicals if you are E deficient?
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neurons (large surface area of cell membrane)
RBCs (because of oxygen radicals created during the oxygenation of Hb) |
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Since E is easy to get in your diet, what are the causes of E deficiency? (3)
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fat malabsorption (cholecystitis)
infant low birth weight w/immature GI tract genetic disorders dealing w/absorption and metabolism of E |
