HAEMOTOLOGY Flashcards
Haemotapoiesis
- blood cell formation
- Produced by hematopoietic stem cell
- Can form common myeloid or lymphoid progenitor
Plasma proteins
Albumin
Globulin
Fibrinogen
Regulatory proteins
Other solutes in blood
Electrolytes
Organic nutrients
Waste
Lymphoid progenitor
Produces white blood cells
Myeloid progenitor
Produces Myeloblast
Cytokines, growth factors and hormones
Thrombocytes
Macrophages
Erythropoiesis
Formation of red blood cells
Requirements for erythropoiesis
- Erythropoieten
- Iron
- Vitamin B12, folic acid
- Intrinsic factor
- Amino acids
Where does erythropoiesis occur in adults?
Only red Bone marrow
Where does erythropoeisis occur in foetus
Yolk sac
then liver and spleen
then bone marrow
life span of RBC
120 days
What substances are recycled for breakdown of RBCs?
Ferritin
Iron
Transferrin
Amino acids
Whats secreted into the bile from leftover RBC breakdown?
Bilirubin
What breaks down old RBCs?
Macrophages
Causes of hypoxia
- Increased exercise
- High altitude
- Smoking
- Bleeding
What detects hypoxia?
Kidneys - produce EPO
Haemoglobin synthesis occurs in ?
Proerthroblast
How much Hb in blood?
15g/dl
Components of Hb
2 alpha subunits
2 beta subunits
Each bound to haem Fe2+
What does Hb carry?
Oxygen
CO2
CO
H+
Anaemia
Low Hb level in blood
Causes of anaemia
- Decreased RBC production
- Increased RBC destruction
- Blood loss
Types of anaemia
Iron deficiency anaemia Megaloblastic anaemia Folic acid deficiency Sickle cell anaemia Thalassaemia
Iron deficiency anaemia
- Most common
- Microcytic and hypocrhomic RBCs
- Decreased MCV
Hypochromic
Pale RBCs due to lack of iron
Microcytic
smaller than normal RBCs due to lack of iron
Causes of iron deficiency anaemia
Pregnancy
Malnutrition
Malabsorption
Bleeding in GI tract Menorrhagia
Malabsorption
Improper absorbing of nutrients from gut, e.g. chrons disease
Menorhagia
XS bleeding during menstruation
Where do white blood cells come from?
Lymphoid progenitor
Eosinophils
Bilobular nucleus
1-3 days
Attack parasites, bacteria and debris by releasing toxic compounds
Allergies and asthma
Basophils
S shaped nucleus Large granules Inflammatory response Unknown lifespan Least common
Monocytes
Largest
Horse shoe shaped nucleus
Become tissue macrophages
Phagocytic
Lymphocytes
Smallest
Weeks to years
Central role in immunological defense
Three types
T cells
Mediate cell-mediated immunity
B cells
Differentiate into plasma cells and secrete antibodies
Natural killer cells
Surveillance, prevent cancer
Phagocytic white blood cells
Neutrophils
Eosinophils
Monocytes
Normal WBC count
4-11 x 10^(9) / litre
Granulocytes
Neutrophils
Eoisonphils
Basophils
Agranulocytes
Lymphocytes
Monocytes
All white blood cells can
Migrate out bloodstream
Amoeboid movement
Attract to specific stimuli
Haemostasis
Process by which body forms clot to protect you from losing blood.
Fibrinolysis
Fibrin clot broken down by plasmin
Where are platelets produced ?
Megakaryocyte cytoplasm
Elements of haemostatic response
Vasoconstriction
Platelet adhesion & aggregation
Clotting
Normal life span of platelets
7-10 days
What substances cause vasoconstriction following a cut to the skin.
5 HT
Thromboxane A2
What does ADP cause in vasoconstriction during haemostasis?
Causes platelets to change shape and swell, causing positive feedback as greater aggregation occurs.
Factor 10 activates
Prothrombinase
Thrombin catalyses
Fibrinogen to fibrin
Anticoaguants
Antithrombin
Heparin
