Blood Flashcards
What are the two pathways of clotting coagulation
Extrinsic pathway
Intrinsic pathway
Describe the intrinsic pathway
Triggered by internal damage to the vessel walls
Describe the extrinsic pathway
Triggered by external trauma which causes blood to escape circulation
Describe the intrinsic pathway of the clotting cascade
12 - 12a
11 - 11a
9 - 9a
How is 12 activated
Comes into contact with negatively charged collagen on the damaged endothelium
Describe the extrinsic pathway
3 activated 7 - 7a
How is 3 involved
released by damaged cells outside the circulation
What activates 10
10
7 and 9
What is the common pathway
Activation of 10 and everything after
Describe the clotting pathway
10 - 10 a
Activated 2 - 2a
1 - 1a
What is the name of 2
Prothrombin
What is the name of 2a
Thrombin
What is the name of 1
Fibrinogen
What is the name of 1a
Fibrin
How are cross linked fibrin clot formed
Fibrin and 13
How do you remember the clotting cascade
Extrinsic pathway 3 + 7
Intrinsic pathway 12 + 11 + 9 + 8
10
Clotting pathway 5 x 2 x 1 = 10
What antibodies in plasma does A group have
Anti-B
What antibodies in plasma does B group have
Anti-A
What antibodies in plasma does AB group have
None
What antibodies in plasma does O group have
Anti-A
Anti-B
What antigens in red blood cells does A group have
A
What antigens in red blood cells does B group have
B
What antigens in red blood cells does AB group have
A and B
What antigens in red blood cells does O group have
None
Does Rh+ have an antigen
Yes - Rh D
Does Rh- have an antigen
No
What can Rh+ receive blood from
Rh+
Rh-
What can Rh- receive blood from
Rh-
What is significant about Rh-
Anti-D antibody is usually absent until they are exposed
Cannot be given transfusions as Rh+ can cause Rh- to develop antigens
What are universal donors
O-
Why are O- universal donors
RBCs have no A, B or RhD antigens
What are universal recipients
AB+
Plasma does not contain anti-B, A or Rh-D
Describe platelets
Not true cells - cellular fragments
Do not contain a nucleus - do not have mitochondria
7-10 days lifespan
What do platelets originate from
Megakaryocytes
What are the two types of platelet granules
Alpha granules - high MW
Dense granules - low MW
Give examples of alpha granules
Von Willebrand factor
Factor V
Fibrinogen
Give examples of dense granules
ATP
ADP
Serotonin
Calcium ions
What are the two surface receptors on platelets
Agonist
Adhesion
What is the role of agonist surface receptors
Recognise stimulatory molecules
What is the role of adhesion surface receptors
Promote adhesion of platelets
What are the 3 roles of platelets
- Adhesion
- Activation
- Aggregation
Describe the role of platelets in adhesion
Injury exposes underlying endothelium and collagen fibres
Collagen fibres bind to VWF released from damaged endothelium
VWF promotes platelet adhesion
Describe the role of activation of platelets
Platelet binds to collagen - glycoprotein 2b = activated
Controlled by G-protein coupled receptors
Secretion of ADP + thromboxane A2
Activate other platelets
Describe aggregation in platelets
Fibrinogen facilitates formation of cross links between platelets - aiding platelet aggregation to form a platelet plug
What happens after a platelet plug is formed
Fibrinolysis
What type of feedback is production of a platelet plug
Positive
What is the breakdown of platelet plug
Liver - plasminogen - plasmin (11a, 12a) - breaks down D-dimers
What does a hemocytoblast differentiate into
Proerythroblast
Myeloblast
Lymphoblast
Monoblast
Megakaryote
What does a proerythroblast differentiate into
Erythrocytes
What does a myeloblast differentiate into
Granulocytes:
Basophil
Eosinophil
Neutrophil
What do lymphoblasts differentiate into
Lymphocytes
What do monoblasts differentiate into
Monocyte
Name the agranulocytes
Lymphocytes
Monocyte
What do megakaryoblasts differentiate into
Megakaryocyte - thrombocytes
Name the leukocytes
Granulocytes
- basophils
- eosinophil
- neutrophil
Agranulocytes
- lymphocyte
- monocyte
What is the size of a red blood cell
6.2-8.2 x 2-2x5 um
What is the lifespan of a red blood cell
100-120 days
What is the size of a white blood cell
7-30um
What is the lifespan of a white blood cell
Hours/days/years
What is the role of white blood cells
Non specific and specific immunity
Give examples of innate immunity
Neutrophils
Eosinophils
Basophils
Macrophages
Mast cells
Give examples of adaptive immunity
B cells
T cells
Give examples of non-specific immunity
Cytokines
Phagocytosis
Cytotoxicity
Give examples of antigen-specific immunity
Cytokines
Antibodies
Cytotoxicity
What is humoral immunity
Secrete antibodies that defend against extracellular pathogens
e.g. B cells
What is cell-mediated immunity
Defend against infected cells, cancers and transplant issues
e.g. T cells
What are the two lineage of lymphocyte maturation from bone marrow stem cells
B lymphocyte
T lymphocyte
Where does lymphocyte maturation begin
Bone marrow stem cell
What is the generative lymphoid organ for B lymphocyte lineage
Bone marrow
What is the generative lymphoid organ for T lymphocyte lineage
Thymus
Where do mature T-lymphocytes go
Blood lymph
Where do mature B lymphocytes go
Blood
What are the peripheral lymphoid organs
Lymph nodes
Spleen
Mucosal and cutaneous lymphoid tissues
Describe the features of a red blood cell
Non nucleated
Biconcave
2-3 million produced and released from bone marrow every second
How are ABO antigens inherited
Mendelian pattern
Each group have a 25% chance of production
Genes code for an enzyme
What are ABO antibodies a mixture of
IgM and IgG
IgM mainly for group A and B
How many Rhesus antigens are there
Over 45
Where is the rhesus antigen genetic locus
Chromosome 1
co-dominant
What can rhesus negative blood cause
Haemolytic transfusion reactions
Haemolytic disease of the fetus and newborn (HDFN)
What is the size of platelets
2-5 um
What is the lifespan of platelets
7-10 days
Describe the structure of platelets
Plasma membrane
Cytoskeleton
Dense tubular system
Secretory granules
What are the secretory granules of platelets
Alpha
Dense
Lysosome
Peroxisome
What are the three levels of platelet activation
Initiation
Propagation
Stabilisation
What % of the plasma do proteins make up
6-8%