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36 Cards in this Set
- Front
- Back
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What are the 2 forms of iron that can exist within the body?
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Fe2 & Fe3
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Which type of iron is contained in plant products?
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non-haem iron
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Where would you find haeme iron?
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mainly in the haemoglobin and myoglobin of animal products
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Where is the majority of iron absorbed?
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duodenum and upper jejunum
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How is iron homeostasis regulated?
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via intestinal absorption
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T/F: Most absorbed iron is used in bone marrow for erythropoiesis
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true
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How is haeme-iron hydrolysed?
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during digestion, with the aid of proteases from the stomach and pancreas
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T/F Haeme iron remains soluble during digestion
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true
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Give one reason why haeme-iron is more bioavailable
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Fe2 crosses the membrane better via a specific transporter- HCP1
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What is the specific transporter that takes ferrous iron across the membrane?
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HCP1
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What is the transporter that facilitates non-haeme iron transfer across intestinal cells?
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divalent metal transporter 1 (DMT1)
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List some factors that inhibit iron absorption
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milk, phytates, calcium, zinc, manganese, GIT blood loss, helicobactor pylori infection
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List some factors that enhance iron absorption
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alcohol, meat, erythropoiesis, fructose, vitamin C
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Where does the regulation of iron uptake occur?
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basal membrane of the intestinal mucosal cells
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What is aptoferritin?
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An iron binding protein
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In the blood, how is Fe2 reoxidised to Fe3?
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by ferroxidase, and then carried by the serum protein transferrin
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Where is iron stored?
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mostly in the liver, as ferritin or haemosiderin
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In times of excess iron, where is the iron deposited?
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heart and liver
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How is most iron transported?
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in the bloodstream, bound to the glycoprotein transferrin
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What is ceruloplasmin?
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a plasma copper-containing protein which catalyses oxidation of Fe2 to Fe3
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What is the main hepatic iron store at lower iron concentrations?
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Ferritin
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What is the main iron store at higher iron concentrations?
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Haemosiderin
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Give two examples of high iron concentrations:
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haemosiderosis and hemochromotosis
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Release of iron from iron stores requires:
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riboflavin as FMNH
niacin as NADH Vitamin C Copper in ceruloplasmin |
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How is iron excreted in the body?
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bleeding
sloughing of cells menstrual flow transfer to developing foetus |
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T/F the body's iron content is regulated via absorption, not via excretion
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true
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What are the main functions of iron in the body?
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oxygen transport and storage
energy metabolism DNA synthesis antioxidant |
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What is irons major role in the body?
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to transport oxygen from the lungs to the rest of the body and within the muscle cells
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What is the clinical deficiency for iron?
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Iron deficiency anaemia (hypochromic macrocytic anaemia)
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List the 3 stages of iron deficiency anaemia
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1. low ferritin storage levels
2. red blood cell formation impaired 3. red blood cell formation inhibited |
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List some symptoms of iron deficiency
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fatigue, lethargy, increased lead absorption, decreased antioxidant levels
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List some signs of iron deficiency
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pale inside lower lid, brittle hair, rigid thin nails, impaired cognitive and motor function
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Who is most at risk for iron deficiency?
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infants and children between 6 months to 4 years
malabsorption syndromes vegetarians gastric bypass regular intense exercise |
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What are some foods that are high in iron?
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beef, oysters, prune juice, lentils, tofu
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What are the two types of hereditary anaemia?
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Thalassemia
Sideroblastic |
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Are there any adverse reactions associated with iron supplementation?
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gastrointestinal disturbances may occur
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