Blood and Immune [Blood Components & Function] Flashcards
3 components produced by centrifugation
Packed red cells 40%
Buffy coat 10% WBC
Plasma 50% soluble proteins, lipids, platelets.
Albumin
Made by liver. Osmotic pressure between blood and surrounding tissues. Bonds and transports small molecules & hormones. Protein sponge - absorbs fluid in blood. Hyper tonicity.
Immunoglobulins
Antibodies. Diverse repertoire of antigen binding proteins. Produced by plasma cells. Found in Y fraction. Becomes elevated in diseases such as multiple myeloma.
What do common myeloid progenitors give rise to? What type of immunity?
Myeloid: erythrocytes, mast, megakarycytes (=thrombocytes), myeloblast (=Phils and monocyte which becomes macro)
Innate immunity.
What do common lymphoid progenitors give rise to?
Lymphoid: killer cell, small lymphocyte (=T and B. B become plasma cells.)
Adaptive immunity.
GM-CSF
Granulocyte macrophage colony-stimulating factor.
Made by T cells, endothelial cells, macrophages, fibroblasts.
Stimulates production of phils + monocytes.
G-CSF
Granulocyte colony-stimulating factor.
Produced by many different cells.
Stimulates production of granulocytes and matures neutrophils.
What is C3?
The most abundant complement protein in serum.
What is electrophoresis and what does it do?
Separation of blood using electric field. Separates serum into 5 protein fractions - albumin, A1, a2, B and Y.
What is plasma?
The viscous liquid fraction of blood without cells. Contains fibrinogen that is removed withal coagulation.
What carries oxygen from the lungs to tissues?
Haemoglobin, the major protein in RBC.
How does haemoglobin get O2 to tissues?
Under the pO2 of oxygen in the lungs, O2 freely binds to Fe2+ in the haemoglobin molecule. When the pO2 drops in the tissue, O2 dissociates and is replaced by CO2.
Classical pathway for complement
Antibodies bind to the surface of a microbe. C1-4 condense on the antibody to form C3 convertase on the microbe surface.
Complement: What are convertases?
Deposited complexes that activate more complement that then coats the surface. Convertases are bound through a covalent bond.
Complement: What are anaphylotoxins and what produces them?
Anaphylatoxins are small polypeptides generates by cleavage of larger complement proteins C3-5. They are chemoattractants C3a, C4a, C5a which activate neutrophils.
End stage complement
The surface bound convertases activate complement C5-9. This forms a lore that inserts into some bacterial membranes to cause lysis. The pore is called the MAC (Membrane Attack Complex).
What are virulence factors?
Proteins produced by microbes that inhibit the complement cascade.
Complement: Alternative pathway
Complement C3 is activated just by being close to the surface of a microbe. This activates another type of C3 convertase.
Complement: Lectin pathway (and what are lectins?)
Lectins are carbohydrates binding proteins in blood that bind to unusual carbohydrates found only on microbes. Complement condenses on these bound microbes.
Coagulation: Intrinsic pathway
Caused by contact with surfaces. Factors 12, 11, 9 and 8 cleave factor X that converts prothrombin to thrombin.
Coagulation: Extrinsic pathway
Caused by tissue damage. Factors 7 and tissue factors TF combine to activate factor X.
Coagulation: what is plasminogen and what is it converted to?
A protease activates by tissue plasminogen activator (TPA) or streptokinase. Converted to active plasmin which dissolves the clot.
Thrombolysis
Dissolving of the clot.
Oxyhaemaglobin ligand, colour and condition
O2
Bright red
Normal oxygenated blood
Carbamihaemaglobin ligand, colour and function
CO2
Dark red
Venous blood
Carboxyhaemaglobin ligand, colour and condition
CO
Cherry red
Carbon monoxide poisoning
Cyanohaemaglobin ligand, colour and condition
CN, pink, cyanide poisoning
What is a protease?
An enzyme which breaks down proteins etc.
