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52 Cards in this Set
- Front
- Back
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What are the 3 layers of the normal vessel wall??
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1. intima 2. media 3. adventitia
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The intima is the _____ layer.
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innermost
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What is the function of the intima layer of a vessel?
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Separates the blood from the vessel
*forms a barrier separating the fluid contents within the BV from the highly thrombogenic material in the subendothelial space |
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What is the intima made up of??
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endothelial cells
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Name 5 things that are synthesized and secreted by endothelial cells.
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1. Von Willebrand factor
2. Tissue factor 3. ADP 4. NO 5. Prostacyclin |
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What does Von Willebrand factor do within the intima layer??
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it is a cofactor for the adherence of platelets to the vessel wall
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What does tissue factor do within the intima layer?
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activates the clotting cascade
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What does ADP do within the intima layer?
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controls blood flow by vasoconstriction
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What does NO and prostacyclin do within the intima layer?
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controls blood flow by vasodilation
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What is the 2nd layer of the vessel wall called?? what is another name for it??
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Media or Thombogenic layer or subendothelial
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What does the media layer of the vessel wall contain?? and what does it do?
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collagen-which stimulates platelet attachment to the vessel wall
this layer if very active.. it facilitates the anchoring of fibrin during the formation of a plug |
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What is the 3rd layer of the blood vessel called? and what is it responsible for?
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Adventitia - controls blood flow and influences vessel contraction
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What influences the adventitia layer and where do these influences come from??
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NO and prostacyclin
these are produced by endothelial cell |
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Within the adventitia layer, what does NO do??(4 things)
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1. inhibits platelet adhesion
2. inhibits aggregation 3. inhibits binding of fibrinogen between glycoprotein IIb/IIIa complex 4. promotes smooth muscle relaxation resulting in vascular vasodilation |
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NO causes a metabolic reaction to occur within the endothelial lining of the vessel, what exactly happens??
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L-arginine is converted into NO which activates guanylate cyclase producing cyclic GMP which causes muscle relaxation
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What is prostacyclin synthesized from??
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prostaglandin
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Prostacyclin is a powerful ________.
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vasodilator
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What does prostacyclin do??
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interferes with platelet formation and aggregation
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What are platelets formed from??
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formed in bone marrow from megakaryocytes
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Where are platelets typically located within the vessel???
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they tend to be pushed against the lining of the vessel
they are smaller than other constituents of blood, therefore they are strategically pushed away to the vessel edge to be available to react to injurie |
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Platelets contain contractile proteins..what are these proteins in charge of??
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storing large amounts of calcium and enzymes
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Platelets contain alpha and dense granules..what do each of these granules do??
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alpha --- store proteins such as vWf, fibrinogen, fibronectin, platelet factors4, platelet growth factor dense --- store nonproteins such as serotonin, ADP, ATP, histamine, epi
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What do platelet granules synthesize??
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prostaglandins - these help to promote vascular and local tissue reactions
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What do platelets produce during the initial portion of vessel injury?? and what does this do??
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thrombin
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Platelets are typically unactivated, what activates them?
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vascular injury
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What occurs in response to injury the vessel???
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the formation of a clot
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What are the steps of hemostasis when vessel injury occurs?
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1. vessel spasm
2. formation of the platelet plug 3. blood coagulation 4. clot retraction 5. clot dissolution |
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What initiates the constriction of the vessel during injury?
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neural reflexes- vessel wall will immediately contract to decrease blood flow via
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When the vessel spasms to constrict the tissue what is released??
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thromboxane A2, ADP and prostacyclin
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What does Prostacyclin do when released during vessel spasm after injury??
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dilates the surrounding tissue to prevent further bleeding, sends blood to surrounding organs and tissues instead of site of injury
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The outer coating of a platelet is covered by _____.
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glycoproteins,
GPIIb/IIIa binds fibrinogen and bridges one platelet to another. |
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After the vessel contracts, then what occurs??
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Formation of the platelet plug
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What occurs during the formation of a platelet plug??
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vWF moves from endothelial cells and adheres to the damaged vessel
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Platelets change their shape once activated..what is this shape and why do they do this???
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change from round disc like shape to an odd shaped form (oval and irregular) to create a block and prevent bleeding, when they change shape they also release their contents
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What are the parts called that stick out from the platelet??
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glycoproteins...these parts help the platelets stick together and they also help in promoting healing
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Platelet adhesion can not occur without??
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vWF
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What activates the platelet??
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Thrombin (factor IIa),also vascular injury starts the whole process
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When they platelet is activated what is released from the platelet??
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thromboxane A2 and ADP
**at different parts through the repair of the vessel, they also release thrombin and growth factors |
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What does P-selection have to do with the platelet plug formation??
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it participates in aggregation
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Defective platelet plug formation occurs in patients who are deficient in ___ or ____ ____ ____.
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platelets or Von Willebrand's Factor
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Platelets also release growth hormones during the formation of the platelet plug..why is this??
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they are released for endothelial and arterial smooth muscle cells...they help maintain normal vascular integrity.
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Name a few drugs that inhibit platelet function??
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1.ASA
2. ticlid 3. plavix 4. integrillin 5. aggrostat 6. reopro |
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What does ASA block to inhibit platelet function?? How long does ASA work??
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blocks cycloxgenase --- blocks enzyme TXA2, works for the life of the platelet
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What does Plavix and ticlid inhibit to block platelet function?
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ADP pathway
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What do integrilen, aggrostat and reopro block??
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fibrinogen receptors
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What are 3 requirements for the blood clotting process???
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1. presence of platelets 2. vWF 3. clotting factors synthesized
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What is the platelet plug reinforced by??
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fibrin clot
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Name these clotting factors 1,2,3,4,8,9,13:
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1. fibrinogen
2. prothombin 3. tissue thromboplastin 4. ionized calcium 8. antihemophilic factors 9. plasma thromboplastic component or Christmas factor 13. fibrin stabilizing factor |
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What does the "a" after a factor mean??
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it has been activated
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Once these factors are activated..what are they called: 1,2,8,9
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1. fibrin
2. thrombin 8. hemophilia A 9. hemophilia B |
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List the clotting factors in the INTRINSIC pathway...
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12 ----> 12a
11 ----> 11a 9 ---->9a 8a then combines with extrinsic to make the common pathway |
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List the clotting factors in the EXTRINSIC pathway...
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factor 3 and 7 -
combine with 10 to complete the common pathway |
