Blood Flashcards
Describe the process of haemostasis
- Process that stops
bleeding and prevents
blood loss through vessel
walls - Allows repair after tissue
damage - 3 overlapping phases
• Vascular phase
• Platelet phase
• Coagulation phase
What happen in Vascular Phase of coagulation?
When wound cut, it will trigger vascular spasm. Endothelial cells become sticky and last 30min
What happen in Platelet Phase of coagulation?
1) Platelet will aggregate at site to form a plug after 15min
2) Clotting factors that converts soluble fibrinogen into insoluble fibrin
3) As fibrin network grows, blood cell and platelet are trap within tangle to form blood clot
What happen in Coagulation Phase of coagulation?
Converts fibrinogen into fibrin and happen 15 sec after injury
What are the 3 pathways which ultimately results in a bld clot?
1) Extrinsic pathway
2) Intrinsic pathway
3) Common pathway
Where are plasma protein being produce?
liver
What are the ingredient needed for clotting to happen ?
11 plasma protein that exist as proenzymes and Calcium ions
What will activate the intrinsic pathway ?
1) When blood expose to collagen because endothelium cut
2) Require platelet factors
3) Need to activate Factor X (10)
For intrinsic pathway, what are the factor being activated?
12 -> 12a
11 -> 11a + calcium ions
9 -> 9a
8 -> 8a
10->10a + calcium ions
What will activate the extrinsic pathway?
1) When there trauma happen to blood vessel. It help activate tissue thromboplastins.
2) Occurs in bloodstream
3) Requires assistance of platelet factors
For extrinsic pathway, what are the factor being activated?
3 (tissue factor) + calcium ions + VII (7)
10 -> 10a
What will trigger the common pathway during coagulation?
1) Enzymes from both intrinsic and extrinsic activate factor 10
2) Prothrombin is converted to thrombin by prothrombinase enzyme
what will thrombin do ?
- It will help convert fibrinogen to fibrin
(fibrin tread is form by factor 1 ,12a and calcium ions - activate protein C
- Provide feedback of thrombin
What is Clot Retraction?
Platelets contract and pull torn area together after clot has formed. this is to reduces size of damaged area
What is the fibrinogen conversion to fibrin process ?
1) Proteolysis - Use thrombin to remove to become fibrin monomer
2) Polymerization - form fibrin polymer
3) Stabilisation of fibrin polymer - Insoluble fibrin clot
Why vitamin K is important for coagulation ?
Produce by liver
- to produce prothrobin coagulation
- Produce factor 7 , 9 ,10
- Produce circulatory anticoagulant protein
What happen when there is vitamin K missing?
1) Increase prothrobin time and blood clotting time
2) Serious haemorrhage may happen
What is subendothelial tissue in coagulation ?
Made of collagen fibres
Why blood circulating in in body do not clot
- Blood circulate at constant velocity
- Endothelial is smooth
- Glycocalyx prevent clot
- There are anti coagulant in the blood (e.g. heparin, Antithrombin 3, Alpha 2 Macroglobulin, protien C
What type of health condition result in blood coagulation ?
- Altherosclerosis
- Hypertension Haemodynamic stress
- Arterial disease
- Diabetes
- hypercholesterolemia (high blood cholesterol )
When will hypercoagulability happen?
1) Increase in clot factor , fibrinogen, prothrombin factor 6a,7 ,10a
2) Increase in platelet count and adhesiveness
3) Decrease in coagulation inhibitors, antithrombin 3 and fibrinogen degradation products
What is the roles of liver in blood coagulation ?
1) synthesis of procoagulant
2) Produce 5,7,9,10 prothrombin & fibrinogen
3) To help remove activated procoagulants
4) Synthesis of anticoagulant (Heparin, antithrombin 3 and protein C)
How will liver failure affect blood coagulation ?
- Result in bleeding disorder due to hypo coagulability of blood
- Uncontrolled extensive clotting inside the blood tissue
What roles does Endothelium play in blood coagulation ?
- Smooth Endothelium cell prevent platelet aggregation
- PG12 prevent platelet aggregation
What effect will thrombi have in the blood?
- Ischemia and infarction happen
- Reduce or stop blood flow to organ
What is thromboembolism ?
Thrombi break off and flow with blood to another location . (eg pulmonary embolism , cerebral embolism
How to prevent thrombi ?
1) Use drug to lower platelet adhesiveness - Aspirin, Dextran , Dipyridamole
2) Anticoagulant - Heparin and Dicoumarol
3) Intermittent compression or electrical stimulation of calf muscle
What is INR (International Normalized Ratio)
It is a standardized value for (PT)Prothrombin Time that is often quoted when following warfarin therapy. The normal value is set at 1.
What does elevated INR indicates? (International Normalized Ratio)
An elevated INR indicates relative increase in anti-coagulation (i.e. INR = 2-3)
What is observe during warfarin therapy ?
↑ Prothrombin Time(PT) can be seen with warfarin therapy, or any process affecting the synthesis of coagulation factors (i.e. liver disease and DIC; respectively).
Prothrombin Time (PT) evaluate what?
measures the integrity of the extrinsic system as well as factors common to both systems
PTT (Partial Thromboplastin Time) evaluation what ?
evaluates the intrinsic system: Factors XII, XI, IX, VIII, X, V, II and I. (1,2,5,8,9,10,11.12)
What is use to depress clotting response
heparin, coumadin, aspirin
What is use to dissolve existing clots?
tissue plasminogen activator (t-PA) produce by thrombin, streptokinase, urokinase
What is Fibrinolysis?
- Gradual dissolution of clot
- Happen by conversing of plasminogen into plasmin
- Plasmin digests fibrin and breaks down clot → restores circulation
How long can platelet circulate ?
9-12day
Platelet is remove by which organ?
spleen
Thrombocytopenia
low platelet count
Thrombocytosis
high platelet count
What the use of platelets?
Initiate clotting process and help close injured blood vessels
Where does platelet cell come from ?
• The platelet cell fragments are
from megakaryocytes
- It is a large multinucleated
cells in bone marrow - It will continuously shed small membrane enclose packages ( platelets)
Explain WBC production?
It is produce by Hemocytoblasts in red bone marrow
It will either become Myeloid stem cell or Lymphiod stem cell
What is in Myeloid Stem Cells
RBC
Platelets
Neutrophils
Eosinophils
Basophils
Monocytes
What is in Lymphoid Stem Cells
Lymphocytes
What is Lymphocytes
- 20–30%
- white blood cell with a single round large nucleus, occurring especially in the lymphatic system.
- Larger than RBC
- Migrate in and out of blood
- Functions is produce antibodies
What is Monocytes
- 2-8%
- Large (2x size of RBC) - Large, kidney-shaped nuclei
- Remain in bloodstream for only 24 hrs
- Function as Phagocytic cell (ingest bacterial) and also Release chemicals that attract other phagocytes
What is Basophils
- Smaller, relatively rare
- < 1% of WBC
- Smaller than neutrophils
- Look deep blue granules on staining
- Function - Promote inflammation by releasing chemicals eg: histamine, heparin
What is Eosinophils?
- 2-4% of circulating WBCs
- Smaller than Neutrophils
- 2 lobed nuclei with deep red stain cytoplasm surrounding
-Function
• Phagocytic
• Secrete enzymes, toxins to kill FB
• ↑ in parasitic infections, allergies
What is Neutrophils?
- 50-70% of circulating
WBCs ( Common WBC) - 2-5 lobed nuclei round cell
- • First WBCs to arrive at injury site
• Active phagocytes (attack, digest
bacteria)
• Release chemicals that attract
other neutrophils
• Short life span (10 hrs)
Characteristics of WBCs
- Capable of amoeboid movement (Move along walls and through tissue)
- Capable of diapedesis ( migrate out of bloodstream by squeezing between
adjacent epithelial cells) - Positive chemotaxis(Attract to chemical stimuli eg pathogens,
damaged cells) - Some are phagocytic ( Neutrophils, eosinophils, and monocytes)
What are type of WBC
Granulocytes
Agranulocytes
What are the Agranulocytes WBC
- Monocytes
- Lymphocytes
What are the Granulocytes
- Neutrophils
- Eosinophils
- Basophils
What is Leucocytes
WBC
What is Cross Reactions?
• Also known as transfusion reactions
• Occur when blood of 1 bld group is mixed with
another bld group
When should Group and Cross-Matching test be done?
• Should be performed whenever possible
• Eg: Elective operations
• Ensures compatibility of donor blood with recipient’s 50
RBC Ag
• Exposing donor RBCs to recipient’s plasma and observing for
any x-reactions
What is the purpose of Blood Type Testing
Determines blood type and compatibility
What make up blood?
• Plasma
• Elements
(Red blood cells, white blood cells, platelets)
What are the 3 type of plasma proteins ?
3 main types
• Albumin
• Globulins
• Fibrinogen
What is plasma ?
Look like interstitial fluid
• Except that plasma has 5X
more plasma proteins
What is the composition of plasma ?
- Water (92%)
- Plasma proteins (7%)
- Other solutes (1%)
What is plasma protein Albumin use for?
Functions
• Major contributor to
osmotic pressure of
plasma
• Transports lipids, cholesterol
What is plasma protein Globulin use for?
2 types
1) Immunoglobulins(antibodies)
• Produced by lymphocytes
• For body’s defence (against
antigens)
2) Transport proteins
• Bind to hormones eg thyroid hormones
What is Fibrinogen use for ?(Plasma Proteins)
• Required for blood clotting
• Forms insoluble fibrin (clot)
• Serum - Fluid left after clotting proteins have been
removed
erythrocytes
Red blood cells use to transport O2 (99.9%)
leukocytes
Part of immune system
thrombocytes
Cell fragments required for clotting
Functions of Blood
- Transportation of dissolved gases, nutrients, wastes
- Regulation of pH, ion composition of interstitial fluid
- Stabilization of body Temp
- Defence against toxins, pathogens
- Restriction of fluid loss at injury sites
Hemopoiesis
• Process of blood cell production
Recycling Hemoglobin Big Picture
*Globin, a protein, is recycled to amino acids for reuse.
* Iron (FE3+) is carried by Transferrin to the liver where it is kept as Ferritin; if it is needed, it is carried by Transferrin to Red Bone Marrow for incorporation into new red blood cells.
*Heme (pigment) is converted to Bilirubin in the Liver where it assists with bile which helps with digestion in the small intestines.
Recycling Globin
Protein, is recycled to amino acids for reuse.
Recycling Iron
Carried by Transferrin to the liver where it is kept as Ferritin; if it is needed, it is carried by Transferrin to Red Bone Marrow for incorporation into new red blood cells.
Recycling Heme
Pigment, converted to Bilirubin in the Liver where it assists with bile which helps with digestion in the small intestines.
which organ signal the producing RBC and what protein is needed
kidneys increasing their erythropoietin (EPO) secretion to signal bone marrow make RBC
People living at high altitudes usually have higher or lower RBC count as a response to lower oxygen levels
higher
Hemopoiesis( formation of mature blood cells) for fetus occur where?
Occur in yolk sac in the 1st 8 week , 2-5th mth liver and spleen
Adult occure in bone marrow
what happen to old red blood cell
Removed from the circulation by macrophages in spleen and liver, and the hemoglobin they contain is broken down into heme and globin
what are the stages of Erythropoiesis (form RBC) production
- Myeloid cell break down to form proerythroblast
- Erythroblast is form , they are immature RBC that produce Hb actively
- Reticulocytes , No nucleus; remnants of RNA
- Mature RBC
Type A blood
- Antigen (agglutinogen) A on RBC surface
- Antibody (agglutinin) B in plasma
Type B blood
- Antigen B on RBC surface
- Antibody A in plasma
Type AB blood
- Both antigens A and B on RBC surface
- Neither antibody A nor B in plasma
Type O blood
- Neither antigen A nor B on RBC surface
- Both antibody A and B in plasma
Rhesus System - Rh +ve:
Rh Ag present; no anti-Rh Ab
Rhesus System - Rh –ve:
No Rh Ag; no anti-Rh Ab
Identify each type of Types of WBC(White Blood Cells)
