Minerals - iron Flashcards
What are the two types of minerals in the body?
Major minerals (present in amounts greater than a teaspoon) eg calcium, sodium, potassium
Trace minerals (present in small amounts/ required much less) eg iron, zinc, iodine
What is the main role of iron in the body?
Iron is essential for transporting oxygen around the body In red blood cells it is found on the haemoglobin molecules and in muscle cells it is found on myoglobin molecules.
How is iron removed from the body?
The only way iron can be removed from the body is through the blood - eg when a women menstruates or when you are gut and bleed out.
It can however also be removed by daily shedding of enterocytes in the GI tract which exit the bod in the faeces.
What are two likely causes of someone having iron deficiency anaemia?
Not enough dietary intake of iron, if they are bleeding out somewhere in the gut, or if they have a mass/tumour that is drawing blood away from the gut to feed itself
What percentage of the bodies iron is found in found in hemoglobin and myoglobin?
70%
What percentage of the bodies iron is stored as ferritin (in the body cells and in the circulation?
25%
When a RBC comes to the end of its life, what happens to it?
An old RBC will get dismantled/broken down by the spleen and the liver and the iron which was on the hemoglobin will be packaged into transferrin (which is carried in the blood) and any excess iron will be stored as ferritin (which is mainly stored in liver, spleen, skeletal muscle and bone marrow - very little is in the blood).
The transferrin then travels in the blood where is delivers some iron to myoglobin in muscle cells and the rest is delivered to the bone marrow where the iron is incorporated into RBC’s and the excess is stored as ferritin.
What happens to iron once it is taken up in the duodenum by mucosal cells?
Once in the mucosal cells the iron is stored as mucosal ferritin (a storage protein) and then its fate depends on whether the body needs iron or not.
If the body needs iron then the mucosal ferritin releases the iron to mucosal transferrin which hands off iron to another transferrin that then travels through the blood to the rest of the body.
If the body dosent need the iron then it stays in the mucosal cells as stored ferritin which is then shed in intestinal cells every 1-3 days as they are slothed off.
Why are iron supplments reccommended for pregnant women?
When you are pregnant the blood volume increases so more iron is needed. It is difficult to consume all of this in the diet.
What are the three phases of iron deficiency and what is the distinguishing factor between stage 1-2 and then stage 3?
1 = depletion of iron stores 2 = deficiency in iron
In these first two stages there is normal hemoglobin levels as it is just the stored ferritin levels which are low and so there are no subjective symptoms like shortness of breath in these first two stages, perhaps only some tiredness which is not purely indicative.
3= iron deficiency anemia
In this stage there is low hemoglobin and microcytic anemia (small pale RBC’s under microscope) which will result in very clear symptoms of shortness of breath, tiredness and dizzy when standing up.
