Week 4 Flashcards
(36 cards)
What is the main function of iron in the body?
Iron plays a role in cellular metabolism and is essential for oxygen transport in hemoglobin and myoglobin.
What are the two main types of dietary iron?
Haem iron (from animal products) and non-haem iron (from plant sources).
What is the primary storage protein for iron?
What is the primary storage protein for iron?
What is the role of transferrin in iron metabolism?
It transports iron in the bloodstream to cells that express transferrin receptors.
How is non-haem iron (Fe³⁺) converted to an absorbable form?
It is reduced to Fe²⁺ by Dcytb before being transported into enterocytes by DMT-1.
What is hepcidin’s role in iron regulation?
Hepcidin inhibits ferroportin, reducing iron release into the blood.
Which condition is caused by excessive iron absorption due to HFE mutation?
Hereditary haemochromatosis.
What is the most common cause of anaemia worldwide?
Iron Deficiency Anaemia (IDA).
What are key symptoms of IDA?
Fatigue, pale skin, brittle nails, shortness of breath, and dizziness
What laboratory tests help diagnose IDA?
Low serum ferritin, low hemoglobin, microcytic hypochromic RBCs on a blood film.
What is another name for Vitamin B12?
Cobalamin.
How is Vitamin B12 absorbed?
It binds to intrinsic factor in the stomach and is absorbed in the ileum.
What is the function of Vitamin B12?
It is a coenzyme for DNA synthesis and the conversion of homocysteine to methionine
What is the most common cause of Vitamin B12 deficiency?
Pernicious anaemia due to lack of intrinsic factor.
What is megaloblastic anaemia?
condition where red blood cell maturation is impaired due to defective DNA synthesis (commonly caused by B12 or folate deficiency).
How is pernicious anaemia diagnosed?
Low serum B12, presence of anti-intrinsic factor antibodies, and macrocytic RBCs on blood film
How is pernicious anaemia treated?
Intramuscular B12 injections.
What are the two main oxidation states of iron in the body?
Ferric (Fe³⁺) and Ferrous (Fe²⁺).
Why is haem iron more bioavailable than non-haem iron?
Haem iron is absorbed directly, whereas non-haem iron must be reduced from Fe³⁺ to Fe²⁺ before absorption.
What protein converts Fe²⁺ back to Fe³⁺ in the plasma?
Hephaestin (Hp).
What are the dangers of iron overload?
Excess iron can damage organs like the liver, heart, and pancreas due to oxidative stress.
What is the genetic mutation responsible for hereditary haemochromatosis?
The C282Y mutation in the HFE gene.
How is iron overload treated?
Regular phlebotomy or iron chelation therapy (e.g., desferrioxamine, deferasirox).
Where is Vitamin B12 stored in the body?
Mainly in the liver
