Iron deficiency anaemia

Question 1

What is the average lifespan for a RBC?

Answer 1

120 days

Question 2

What is the average lifespan for platelets?

Answer 2

7-9 days

Question 3

What is polycythaemia?

Answer 3

High increase in RBC production

Question 4

What is the normal levels of haemoglobin in males and females?

Answer 4

Men - 150g/L

Women - 135g/L

Question 5

What reference range of haemoglobin would one have who is deemed to be anaemic?

Answer 5

<105pg/L

Question 6

What is IDA caused by?

Answer 6

A lack of iron available to produce Hb, causing the cells to be microcytic and hypochromic

Question 7

What makes up haemoglobin?

Answer 7

In an adult - 2 alpha and 2 beta polypeptide chains

In a foetus - 2 alpha and 2 gamma chains

Question 8

What is most of the iron in the body recycled by?

Answer 8

The reticuloendothelial system

Question 9

What are the 2 states iron exists in?

Answer 9

Fe3+ (ferric) and Fe2+ (ferrous), ferric is insoluble

Question 10

Why is there very little amounts of free iron in the body?

Answer 10

Because free iron is toxic, causes profound effects on brain function and can cause the heart rate to go above 100bpm (tachycardia)

Question 11

What type of iron is most easily absorbed?

Answer 11

haem iron, primarily in red meats

Question 12

How is iron regulated in the body? (long answer)

Answer 12

As there is no physiological mechanism for regulating iron elimination, iron absorption is a very important role. As iron passes through the duodenum it is brought into the enterocytes via active transport by the protein DMT-1. Once inside the cell, the iron can be bound in the cell as ferritin, bound specifically to apoferritin, which will be stored inside the enterocyte. Alternatively, it can be pass through iron channels via ferroportin and enter the bloodstream to be rapidly bound by apo-transferrin and taken to red blood cell precursors, which take up the iron via receptor-mediated endocytosis.

Question 13

What is hepcidin?

Answer 13

Hepcidin is an iron-regulating hormone that inhibits ferroportins, causing iron to remain inside enterocytes

Question 14

Can iron be stored anywhere besides enterocytes?

Answer 14

Yes, In the blood bound to transferrins they can be taken to sites of storage such as the liver in hepatocytes or can be stored in the bone marrow

Question 15

What is haemoglobin converted into following senescent RBC destruction?

Answer 15

Senescent RBC are ingested by macrophages, which are degraded by hydrolytic enzymes to release the haemoglobin that can be converted into bilirubin

Question 16

What are some signs of IDA?

Answer 16

Angular cheilosis - dry and cracked borders of mouth
Glossitis - smooth and shiny tongue
Koilonychia - spoon shaped nails, brittle