Haematopoiesis and Anaemias

Question 1

3 most important features of RBC

Answer 1

1. Erythrocytes lack most of the organelles, in particular: Nucleus, ribosome, ER, Golgi, secretory vesicles, mitochondria
   2.Haemoglobin ->transport of O2…why not CO2
2. Cytoskeleton and membrane proteins -> support shape and flexibility to squeeze into the capillaries (4-10 μm diameter

Question 2

What is Heme made by

Answer 2

Heme is made by– Fe2+ = reduced form or Ferrous– Protoporphyrin IX mojety

Question 3

What does the heme synthesis required

Answer 3

1.Enzymes -> some of them are mutated in some forms of anaemia
2. Cofactors: vitamin B12, vitamin B6 and folate -> lack will cause anaemia

Question 4

Myeloid lineage and Lymphoid linage

Answer 4

Erythroid lineage = red blood cells
Megakaryocytic lineage =platelets Monocytic lineage = monocytes
Granulocytic lineage = granulocytes

Lymphoid- T, B, NK cells

Question 5

Different types of Anaemia

Answer 5

Iron deficiency Anaemia (IDA)
* Vitamins and micronutrients deficiency anaemia
* Anaemia due to defects in the Bone Marrow and RBC production
* Anaemia from infections (parasitic, viral, bacterial)
* Anaemia of toxic or chemical injuries (snake venom ,lead poisoning)
* Anaemia from chronic diseases and chronic inflammation

Question 6

Main causes anaemia

Answer 6

Iron- Malnutrition and malabsorption
Malaria- parasitic infections
Leukemias- bone marrow disease

Question 7

Where do RBCs come from, what is their role and this the process called

Answer 7

Mature RBCs transport O2 around body
RBCs come from stem cells in the bone marrow
Production of RBCs is erythropoiesis

Question 8

What are the stages of the Erythropoiesis?

Answer 8

1. Stem cells
   2.Proerythroblast
2. Early erythroblast - ribosome synthesis
   4 Late erythroblast - Haemoglobin accumulation
   5.Normubalst
3. Reticulocyte - the nucleus is removed but it is not yet a RBCs it must stay in the bone marrow for 3 days before entering the blood, once it has entered the blood after 24-48hrs to becomes a RBCs

Question 9

What is and where does the RBCS removal( damaged or old) take place?

Answer 9

• It can happen in the spleen, liver and the bone marrow
  1. The macrophages engulf the RBCs and break them down
  2. Then there is a lot of Hemegloblin so it is broken down into heme and globlin heme= amino acids and globlin= bilirubin and iron

Question 10

How are broken down products recycled?

Answer 10

• For amino acids it enters the blood and moves into the bone marrow to be used for erythropoiesis
• For Iron uses transporter known as transferrin which are used for the iron to go back to the bone marrow for erythropoiesis

Question 11

What nutrients are needed for RBCs

Answer 11

• Amino acids
• Monosaccharides
  -Lipids
  -Vitamin B
  -Folic acid
• Iron