Red cell Physiology

Question 1

Describe the process of a red cell being created?

Answer 1

Haemotocytoblast (stem cell)

• -> Proerythroblast (committed cell)
• -> Erythroblast
• -> Normoblast
• -> Reticulocyte (released into blood)
• -> Erythrocyte

Question 2

What substances are used to make RBCs?

Answer 2

Metals
Vitamins
Amino acids
Hormones

Question 3

What metals are required for RBCs?

Answer 3

IRON

Also copper, cobalt & manganese

Question 4

What vitamins are required to make RBCs?

Answer 4

B12 & FOLIC ACID

Also thiamine, B6, C & E

Question 5

What hormones are essential to RBC development?

Answer 5

ERYTHROPOIETIN

Also Gm-CSF, Androgens, thyroxing & SCF

Question 6

What cell breaks down RBCs?

Answer 6

Macrophages in the reticuloendothelial system tissues i.e. spleen, liver, lymph nodes etc

Question 7

What becomes of haemoglobin after a RBC is broken down?

Answer 7

Globin –> Amino acids (recycled)

Haem –> Iron (recycled) & Bilirubin (excreted)

Question 8

How does iron enter from the gut?

Answer 8

Bound to enterocytes (most ends up in your shit) and transported to the plasma by ferroportin protein

Question 9

What happens to Fe once it enters circulation?

Answer 9

Transported around by transferrin

Then it’s stored in tissues as ferritin

Question 10

What does Hepcidin do?

Answer 10

Blocks ferroportin –> decreased iron absorption

It’s produced by hepatocytes in response to inflammation

Question 11

What factors can lower haemoglobin affinity for O2?

Answer 11

Acidosis
Hyperythermia
Higher DPG
Hypercapnia

Question 12

What makes up a normal adult haemoglobin (HbA)?

Answer 12

1 Haem Molecule
2 Alpha globin chains
2 Beta globin chains