Lecture 8 - Haematology Flashcards
How much blood does the average adult have?
5 litres
What is the composition of blood?
Made up of:
Plasma
Red blood cells
White blood cells
Platelets
What is the function of blood?
Transport - gases, nutrients, excretory products
Defence using antibodies, WBC and clotting factors
What is haematopoiesis?
The production of blood cells and platelets
What is the process of haematopoiesis?
- Hemocytoblasts produce all blood cells
- They differentiate into either common myeloid or common lymphoid progenitors depending on body’s needs
- Then differentiate into different types
What is erythropoiesis?
The production of red blood cells
What are the stages of erythropoiesis?
- Stem cell
- Committed cell
- Developmental pathway
- Erythrocyte
What are the stages of the developmental pathway?
- Ribosome synthesis
- Haemoglobin accumulation
(haemoglobin produced by this point - Nucleic ejection
What are the requirements for erythropoiesis?
Erythropoietin
Iron
Vitamins B12 and folic acid
Intrinsic factor
Amino acid
Where does erythropoiesis occur in foetuses?
Early = in yolk sac then the liver and spleen
Later = Bone marrow
Where does erythropoiesis occur in infants?
In all bone marrow
Where does erythropoiesis occur in adults?
Only in red bone marrow
How much of the blood is made up of plasma?
55%
What is plasma made up of?
92% Water
7% Plasma proteins like albumins
1% Other solutes
What is the function of plasma?
Transport of inorganic and organic molecules