Term
| Name 3 basic mechanisms +1 of hemostasis |
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Definition
1) Vascular spasm - damaged arterioles and arteries constrict
2) Platelet plug formation
3) Blood clotting (coagulation)
+1 is Fibrin thread formation |
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Term
| Name 5 steps of clotting (pic on slide 2) |
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Definition
1. Severed vessel
2. Platelets agglutinate
3. Fibrin appears.
4. Fibrin clot forms
5. Clot retraction |
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Term
| How long does clot retraction occur? |
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Definition
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Term
| When does fibrin clot form? |
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Definition
| When fibrin and platelets cross link |
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Term
| What is fragments of precursor megakaryocytic? |
|
Definition
|
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Term
|
Definition
a hormone produced by the liver and kidneys that regulates
megakaryocyte and platelet production |
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Term
| Where are platelets formed? sequestered? |
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Definition
Formed in bone marrow, 150 - 350,000 /µl
Sequestered in spleen, 30% |
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Term
| Plt diameter, life span in days, nucleus or no nucleus? |
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Definition
| Plt 2-4 micrometer in diameter, life span 8-12 days, no nucleus |
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Term
| Which factor crosslinks fibrin |
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Definition
| fibrin stabilizing factor (factor XIII) |
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Term
| 3 things that make up contractile unit and let the plts change shape |
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Definition
| Cytoplasm of plt has actin and myosin contractile proteins and thrombosthenin (an ATPase) - for clot retraction |
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Term
How does appearance differ from Activated plt and
Unactivated plt |
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Definition
Activated plt differ in shape (changes shape when releasing substances to other plts that haven’t been activated.
This activates them to inc number of plts, thus, helping with clotting |
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Term
| When does plt plug formation occur? |
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Definition
| When there is break or damage in basement membrane epithelium and capillary |
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Term
| What is first step of plt plug formation |
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Definition
Platelet adhesion
Platelets stick to damaged area specifically COLLAGEN!! (in basal membrane) |
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Term
|
Definition
| Promotes vasoconstriction and plt aggregation |
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Term
| What is 2nd step of plt plug formation? |
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Definition
Platelet release reaction (de-granulation)
Change shape
Spill contents of their granules: (active others!)
Alpha granules (PDGF)
Dense granules (variety of chemicals) |
|
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Term
| What are Dense granules in plt plug formation |
|
Definition
(containing
ADP or ATP,
calcium, and
serotonin) |
|
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Term
| What are Alpha granules in plt plug formation? |
|
Definition
(containing
platelet factor 4,
transforming growth factor-β1,
platelet-derived growth factor,
fibronectin,
B-thromboglobulin,
vWF,
fibrinogen, and
coagulation factors V and XIII) |
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|
Term
| Platelet aggregation forms this. |
|
Definition
|
|
Term
What is released from damaged cells,
secreted into blood vessel? |
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Definition
| Tissue factor starts the extrinsic pathway |
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Term
| What is required for blood clotting |
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Definition
| Ca++ is required to promote or accelerate all the blood clotting reactions. |
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Term
| What converts prothrombin to thrombin ? |
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Definition
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Term
| What converts fibrinogen to fibrin |
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Definition
|
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Term
| what is INSOLUBLE in extrinsic pathway |
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Definition
|
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Term
| What strengthens crosslinks b/t fibrin threads - to make clot stronger |
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Definition
Factor XIII-
Thrombin activates this |
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Term
| Clot formation operates under what kind of mechanisms. |
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Definition
| Clot formation operates under positive feedback mechanisms. |
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Term
|
Definition
plasmin
Plasminogen is converted to plasmin |
|
|
Term
Prevents clots from spontaneously forming
along epithelium. |
|
Definition
prostacyclin (considered anticoag)
Endothelial cells and WBCs also coated with prostacyclin. |
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|
Term
| What triggers extrinsic and intrinsic system? |
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Definition
the extrinsic pathway, which is triggered by release of tissue factor from the site of injury,
and the intrinsic system, which is stimulated by contact with a negatively charged surface (like collagen). |
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Term
| How many pro-coagulants & anticoagulants that have been identified within the blood. |
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Definition
There are >50 pro-coagulants & anticoagulants that have been identified within the blood.
The “anti” segment normally dominates until damage is sustained. |
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Term
|
Definition
I - fibrinogen
(insoluble) fibrin is Ia |
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|
Term
|
Definition
II - prothrombin
Thrombin is IIa |
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
Stuart factor
activates prothrombin to thrombin- |
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Term
|
Definition
|
|
Term
| High molecular weight kininogen |
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Definition
|
|
Term
| what factor is labile factor, pro-acclerin |
|
Definition
|
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Term
|
Definition
| stabile factor, serum prothrombin conversion accelerator |
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Term
|
Definition
| antihemophilic factor (AHF, globulin or factor A) |
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Term
|
Definition
| AHF B, plasma thromboplastin component, Christmas factor |
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Term
|
Definition
| Plasma thromboplastin antecedent |
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|
Term
|
Definition
|
|
Term
|
Definition
| Fibrin stabilization factor |
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Term
| Which pathway is activated first? Extrinsic or intrinsic? |
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Definition
Both paths are activated simultaneously- its never one or the other!
Goal is to get to thrombin! |
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Term
| Which pathway does the stuart factor get activate? |
|
Definition
Factor X gets activated to Xa on both pathways.
This is critical player b/c it activates prothrombin to thrombin |
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Term
| When does the common pathway begin? |
|
Definition
After Xa
or
After stuart factor is activated |
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Term
| What is the cell surface receptor for factor VIIa |
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Definition
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|
Term
| What allows the complex formation of TF with factor VII. |
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Definition
| Exposure of TF expressing cells during injury |
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Term
| this leads to the activation of factor VII on a membrane surface. |
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Definition
| Factor VII and TF forming an equal molar complex (1:1 ratio) in the presence of calcium ions |
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|
Term
|
Definition
cells which are normally not exposed to flowing blood,
such as sub-endothelial cells (e.g. smooth muscle cells)
and
cells surrounding blood vessels (e.g. fibroblasts).
Endothelial cells do not express TF EXCEPT when they are exposed to inflammatory molecules
such as tumor necrosis factor-alpha (TNF-alpha).
Platelets & monocytes also express TF. |
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Term
| What do plt phospholipids do? |
|
Definition
- stimulate production of thrombin
are helpin to drive coagulation |
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Term
| When blood is removed from a person, clotting can be prevented by? |
|
Definition
by collecting blood with citrate ions
in light blue capped vacu-tainer (containing citrate) or
in purple tops (EDTA) or
green tops (heparin) |
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Term
| What is the important difference between intrinsic and extrinsic pathway |
|
Definition
the SPEED
EX pathway 15 secs
vs
IN pathway 1-6 mins
EX pathway is limited only by the amts of tissue factor & factors V, VII & X in the blood. |
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Term
| Release of tissue factor occurs in which pathway |
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Definition
| Tissue damage will result in release of tissue factor (extrinsic initiation) |
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Term
| collagen contact with Factor XII & platelets occurs in which pathway |
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Definition
| collagen contact with Factor XII & platelets (intrinsic initiation) |
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Term
| What is present in blood plasma independently |
|
Definition
|
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Term
|
Definition
| The term hemostasis means |
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Term
|
Definition
| The megakaryocytes fragment into platelets, becoming smaller by squeezing thru |
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|
Term
|
Definition
| Outer coating of platelet cell membrane that repulses adherence to normal endothelium or causes adherence to injured vessels |
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Term
|
Definition
| once a blood clot is formed, it can become invaded by ______in order to form connective tissue thru the clot |
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|
Term
| procoagulants & anticoagulants |
|
Definition
| whether blood will clot depends on the balance between these 2 substances |
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Term
|
Definition
| what is required by the liver to maintain normal activation of prothrombin? |
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Term
|
Definition
| Interstitial fluid does not normally clot; however increased permeability of the capillaries can allow _______to leak into the tissues to allow clotting |
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|
Term
SERUM
***serum CANNOT clot due to lack of clotting factors!! |
|
Definition
| Fluid is expressed from a formed clot w/in 60min, removing all fibrinogen & clotting factors. The fluid removed is called |
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|
Term
Platelets
***failure of clot retraction indicates low platelets in blood |
|
Definition
| These are necessary for clot retraction to occur |
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|
Term
|
Definition
| Blood clotting by either pathway does not occur in the absence of |
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|
Term
|
Definition
| After a vessel is damaged, what is the 1st step in the extrinsic pathway |
|
|
Term
EDTA
ethylenediaminetetraacetic acid
&
citrate |
|
Definition
| What substances chelates Ca? For example in the test tube |
|
|
Term
|
Definition
| What is needed in order for prothrombin to split & form thrombin? |
|
|
Term
|
Definition
| When platelets come in contact with collagen, they form a plug; however it is the soluble clotting factors making contact with collagen that initiates the |
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|
Term
|
Definition
| This activated factor is the actual protease that causes splitting of prothrombin to form thrombin |
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|
Term
|
Definition
| This activated factor accelerates Xa protease activity, providing quick positive feedback |
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|
Term
|
Definition
| This is the activated form of prothrombin |
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|
Term
|
Definition
| This is the activated form of fibrinogen |
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|
Term
factor VII
***Intrinsic pathway |
|
Definition
| What factor along with Ca+ activates factor X within the intrinsic pathway? |
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|
Term
|
Definition
|
|
Term
|
Definition
| The extrinsic pathway is limited by the amount of tissue factor & also by the amount of these factors (3) |
|
|
Term
|
Definition
| The intrinsic converges with the extrinsic pathway @ the production of |
|
|
Term
1. Sub-endothelial (smooth muscle)
2. fibroblasts
3. platelets
4. monocytes |
|
Definition
| These 4 types of cells express TF |
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