CHAPTER 93 IRON DEFICIENCY ANEMIA AND OTHER HYPOPROLIFERATIVE ANEMIAS

Question 1

What is most common type of anemia?

Answer 1

hypoproliferative anemias

Question 2

most common type of hypoproliferative anemia

Answer 2

iron deficiency anemia

Question 2

most common type of hypoproliferative anemia

Answer 2

iron deficiency anemia

Question 3

is free iron toxic?

Answer 3

yes because it will participates in chemical reactions that generate free radicals such as singlet O2 or OH-

Question 4

what is the major role of iron in mammals

Answer 4

to carry 02 as part of hemoglobin that is bound in myoglobin in muscles
it is a critical element of iron containing enzymes including the cytochrome system in mitochondira

Question 5

what is the iron transport protein?

Answer 5

transferrin

Question 6

what is transferrin?

Answer 6

a bilobed glycoprotein with two iron binding sites

Question 7

iron bind in transferrin exist in 2 forms?

Answer 7

the monoferric and the diferric

Question 8

what is the turnover half time clearance of of transferrin bound to iron

Answer 8

typically 60 to 90 mins

Question 9

what is the half time clearance of iron in the presence of iron deficiency

Answer 9

10 to 15 mins

Question 10

who has the highest affinity for transferrin receptor?

Answer 10

diferric transferrrin

Question 11

what do you call a receptor that does not hold any iron?

Answer 11

apotranferrin

Question 12

who has the greatest number of transferrin receptors in the body?

Answer 12

erythroblast

Question 13

explain the iron cycle in humans

Answer 13

when iron is absorbed from the diet and released in the circulation, it bind to transferrin and deliver to the marrow where transferrin receptor is highest. when they interact the complex is internalized via clathrin coated pits and transported to an acidic endosome where the iron is released at low ph
then it is made available for heme synthesis while the transferrin receptor complex is recycled to the surface of the cell while the transferrin is released back at the circulation while the transferrin receptor re-anchors the cell membrane

Question 14

when there is excess iron where it will go?

Answer 14

it will bind to storage protein called apoferritin forming ferritin

Question 15

how is the rbc recognized of its life span?

Answer 15

recognized by reticuloendothelial system and they undergo phagocytosis

Question 16

what will happen to the ingested hemoglobin?

Answer 16

broken down and the globin and other proteins are returned to the amino acid pool and the iron is shuttled back to the surface of the RE cell

Question 17

additional iron required for daily red cell production

Answer 17

adult male is 1 mg of elemental iron

adult female and child bearing- 1.4 mg

Question 18

what is excretory pathway for iron?

Answer 18

blood loss

Question 19

route for which iron comes into our body

Answer 19

absorption from food or from medicinal iron taken orally

Question 20

why vegetarians is at advantage for iron deficiency anemia

Answer 20

vegetables contain phytates and phosphate that reduce iron absorption

Question 21

what trimester where daily iron requirements is increasedd to 5-6 mg

Answer 21

last 2 trimesters

Question 22

where does iron absorption takes place

Answer 22

duodenum and proximal small intestine

Question 23

the absorption process is facilitated by?

Answer 23

acidic contents in the stomach which maintains the iron in solution

Question 24

where in the stomach in which ferric iron is converted to ferrous form by ferriductase

Answer 24

brush border of the absorptive cell

Question 25

how is transport across the membrane of iron possible

Answer 25

the use of divalent metal transporter type1

Question 26

what are the three stages of iron deficiency

Answer 26

negative iron balance
iron deficient erythroblast
iron deficiency anemia

Question 27

iron negative balance presents as

Answer 27

demands for iron exceeds the body ability to absorb iron from the diet

Question 28

what is the cardinal rule in appearance of iron deficiency anemia in adult male and post menopausal woman

Answer 28

means gastrointestinal blood loss until proven otherwise

Question 29

what are the usual signs of anemia

Answer 29

fatigue
pallor
reduced exercise capacity