Blood 2 Flashcards
What are WBC’s
Leukocytes
What do WBC’s do
Defend against infection
How are WBC’s grouped
- Granulocytes
- Non-granule containing lymphocytes and monocytes
Granulocytes
Contain cytoplasmic granules
Brief lifespan <12 hours in blood
If activated can migrate into tissues for longer time
Types of Granulocytes
Neutrophil
Eosinophil
Basophil
Neutrophil
Most abundant
Granules with lysosomal enzymes capable of digesting foreign material (phagocytosis)
Eosinophil
Granules contain major basic protein which is toxic to parasites and other enzymes
- response to virus’ and allergic reactions
Basophil
Least common, granules contain histamine, heparin and peroxidase
- allergic reactions
Types of non granule WBC’s
Monocytes and lymphocytes
Monocytes
Life in peripheral tissue developing macrophages
What are 2 purposes of macrophages
Phagocytosis of pathogens and cellular debris
Present antigens to lymphocytes
Types of lymphocytes
T cells
B cells
T cells
70-80% of lymphocytes responsible for cell mediated immunities, not involving antibodies
B cells
Responsible for humoral immunity, make antibodies to antigens
What are platelets
Nucleus free fragments of megakaryocytes, 2-3um in inactive state
10 day life span
A single megakaryocyte can produce how many platelets
Thousands
How many platelets for 1ul of blood
150-400 000 platelets
What special types of granules do platelets contain when activated
Dense core granules
Alpha-granules
What are platelets essential in
Hemostasis
Hemostasis
Prevention of hemorrhage (bleeding) from damaged vessel
What are 3 steps of hemostasis
- Vasoconstriction
- Platelet plug formation
- Coagulation
Three parts of coagulation
Intrinsic pathway
Extrinsic pathway
Common pathway
Intrinsic pathway
Surface contact pathway
- factor XII activated when contacting exposed collagen, activated platelets
- final product it factor Xa
Extrinsic pathway
Cell injury pathway
- factor VII leaves vessel and binds to tissue factor receptor and become activated factor VIIa
- final product is factor Xa
Common pathway
Factor Xa from intrinsic and extrinsic is used to create thrombin
Converts fibrinogen to stable fibrin clot
Hemophilia
Factors in coagulation cascade is defective or lacking
- bruise easily, spontaneous bleeding
- bleeding in joints and muscles can be painful and disabling
Hemophilia A
Factor VIII deficiency
80% cases
Hemophilia B
Factor IX deficiency
What is hemophilia treated with
Synthetic factors
Anticoagulant factors
To much coagulation (thrombus can form: stroke, heart attack, pulmonary embolism)
- endothelial cels produce variety of anticoagulant factors that interfere with clotting cascade
What prevents platelet binding
Prostacyclin and nitric oxide
Fibrinolysis (final stage of hemostasis)
Breakdown of blood clots
What happens during fibrinolysis
Conversion of plasminogen to plasmin
Plasmin breaks down stable fibrin as well as fibrinogen
