Haemotology Flashcards
(49 cards)
How much blood does the average human have
5L
How much of the blood is plasma
55%
What are the three main type of cells in blood
White blood cell, red blood cells, platelets
What are the main components of plasma
Water, Albumin, Globulin, Fibrinogen, regulatory proteins and other solutes
What is Haematopoiesis
The process in which blood cells are formed
What can the common lymphoid progenitor produce
Natural killer cells and B/T lymphocytes
What does the common myeloid progenitor produce
Red blood cells, non-lymphocyte white blood cells and Megakaryocytes
What is erthyropoiesis
The process or erythrocytes being produced (red blood cells)
What are the first two cells in erthyropoiesis
Hemocytoblast (stem cell) and then Proerythroblast (committed cell)
What is the developmental pathway in erthyropoiesis
Early erythroblast (ribosomes being synthesised), late erythroblast (haemoglobin accumulation), normoblast (nucleus size reducing and then being ejected), Reticulocyte (Nucleus ejected but some organelles remain).
What is the significant feature of an erythrocyte compared to a reticulocyte
All organelles have been ejected from the cell
What minerals and molecules are needed for erythropoiesis
erythropoietin, iron, vitamins B9, B12, Intrinsic factor (helps absorb vitamin b12) and amino acids
Where does erythropoiesis occur
In the fetus occurs in yolk, then liver and spleen and later in bone marrow, in children occurs in all bone marrow then in adults it occurs in red bone marrow
Why is the biconcave shape of the red blood cell important
Increases surface area, allows the cells to deform and flex - aiding them to navigate tight blood cells
Where are red blood cells broken down
Macrophages break them down mainly in the spleen, liver and lymph nodes.
What is Hb broken down into
Heme-iron-ferritin/iron+transferrin and globin-amino acids
What is the structure of HbA
4 Haem groups with a central iron atoms (2 α groups 2 β groups), each one binded to a separate globin chain
What is the difference in RBC in someone with iron deficiency with red blood cells
Hypochromic (pale RBCs) and Microcytic (small RBCs)
What is megaloblastic anaemia
B12 or B9 (folate) deficiency anaemia
What is the difference between blood in megaloblastic anaemia
Macrocytic cells (larger), reduced Hb conc. and hypersegmented neutrophils
Why does megaloblastic anaemia cause macrocytic cells
Red blood cells don’t divide sufficiently making less but larger cells
Why might IF affect megaloblastic anaemia
Lack of intrinsic factor prevents b12 from being absorbed properly causing this form of anaemia
How are platelets formed
Myeloid stem cells differentiate into megakaryocytes which produce platelets.
What three substances affect the rate of platelet formation
Thrombopoietin accelerates platelet formation and increases megakaryocyte numbers
Interleukin-6 stimulates platelet formation
Multi-CSF promotes megakaryocyte formation and growth