Iron Flashcards

(30 cards)

1
Q

where is iron bound to porphyrin ring

A

mitochondria

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2
Q

what state is iron found in in mitochondria

A

Fe3+

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3
Q

where is iron mostly stored

A

in Hb

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4
Q

other places iron is found

A

plasma
erythroid marrow
macrophages
liver stores

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5
Q

where is iron abdorbed from

A

duodenum

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6
Q

through what transporter does iron enter enterocyte

A

DMT1

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7
Q

how is iron transported out of enterocyte

A

ferroportin

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8
Q

what picks up iron in blood

A

transferrin

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9
Q

what can affect expression of ferroportin

A

hepcidin - decreases expression of ferroportin

traps iron in enterocytes and macrophages

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10
Q

when is hepcidin produced

A

protein produced with increased iron load and in inflammation

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11
Q

what form is it easier to absorb iron in

A

ferrous Fe2+

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12
Q

what does ferritin act as

A

acute phase protein (increased in infection, malignancy, inflammation etc

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13
Q

why do people with chronic diseases become anaemic

A

increased ferritin as response to acute inflammation
hepcidin released in response
prevents iron binding to transferrin
less iron to marrow causing hypochromic red cells

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14
Q

measurement of functional iron

A

Hb conc

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15
Q

measurement of transport iron/iron supply to tissues

A

%transferrin saturation (normal is 20-50%)

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16
Q

measurement of storage iron

A

serum ferritin (requires tissue biopsy)

17
Q

what kind of iron is transported by transferrin

18
Q

what is holotransferrin

A

transferrin + iron

19
Q

what is apotransferrin

A

unbound transferrin

20
Q

epithelial changes of iron deficiency

A

koilonychia

angular stomatitis

21
Q

what kind of anaemia does iron deficiency cause

22
Q

causes of iron deficiency

A

insufficient diet
bleeding (menorrhagia, tumours, ulcers, NSAIDs)
malabsorption

23
Q

how much blood loss can occur per day with no symptoms

24
Q

gene mutated in haemochromatosis

25
pathophysiology of haemochromatosis
decreased hepcidin production | increased unopposed iron absorption
26
clinical manifestations of haemochromatosis
``` weakness/fatigue joint pain impotence arthritis cirrhosis diabetes cardiomyopathy ```
27
penetrance of haemochromatosis
incomplete
28
management of haemochromatosis
weekly venesection (exhaust iron stores)
29
what are secondary causes of iron overloading
repeated cell transfusions ineffective erythropoiesis (thalassaemia, sideroblastic anaemia) hypoplasic anaemia
30
treatment of secondary iron overload
iron chelating agents - desferrioxamine deferiprone deferasirox