Term
| Are platelets types of cells |
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Definition
| No - they are fragments of marrow cells called megakaryocytes |
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Term
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Definition
| Marrow cells - platelets are fragments of these types of cells |
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Term
| The second most abundant formed element |
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Definition
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Term
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Definition
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Term
| Platelets secrete these types of chemicals |
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Definition
| Vasoconstrictors, procoagulants, chemicals that attract neutrophils and monocytes to inflammation, growth factors |
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Term
| The reason why platelets secrete growth factors |
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Definition
| To stimulate mitosis in fibroblasts and smooth muscle - help maintain and repair blood vessels |
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Term
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Definition
| The production of platelets |
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Term
| Some PPSCs produce receptors for this type of hormone, which causes it to become a megakaryoblast |
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Definition
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Term
| True or false - a megakaryoblasts duplicate DNA without undergoing nuclear or cytoplasmic division |
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Definition
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Term
| Megakaryoblasts duplicate their DNA to form this |
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Definition
| A megakaryocyte (giant cell) |
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Term
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Definition
| Red bone marrow - adjacent to blood-filled spaces called sinusoids |
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Term
| Sinusoids are lines with this type of cells |
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Definition
| Squamous celled epithelium called endothelium |
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Term
| Megakaryocytes sprout these, which pass through endothelium and into the blood of the sinusoid |
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Definition
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Term
| What happens after megakaryocytes sprout tendrils (proplatelets) into the blood of sinusoids |
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Definition
| Blood flow sheers of the tendrils (proplatelets) that become platelets |
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Term
| 25-40% of platelets live here |
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Definition
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Term
| The length of time that platelets live circulating in the blood |
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Definition
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Term
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Definition
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Term
| The three haemostatic mechanisms |
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Definition
Vascular spasm
Platelet plug formation
Blood clotting (coagulation) |
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Term
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Definition
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Term
| First mechanism in haemostasis |
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Definition
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Term
| Second mechanism in haemostasis |
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Definition
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Term
| Third mechanism in haemostasis |
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Definition
| Blood clotting (coagulation) |
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Term
| Main action that occurs during vascular spasm |
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Definition
| Swift contraction of blood vessels |
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Term
| The action of pain receptors during vascular spasm |
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Definition
| Some innervate nearby blood vessels and cause them to constrict |
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Term
| Chemical released by platelets due to injury of smooth muscle of a blood vessel |
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Definition
| Serotonin - a chemical vasoconstrictor - causes longer lasting vasoconstriction |
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Term
| The reason why platelets do not adhere to endothelium |
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Definition
| They are smooth and coated with prostacyclin (a platelet repellent) |
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Term
| The platelet repellent that coats endothelium |
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Definition
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Term
| What platelets adhere to when endothelium is broken |
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Definition
| Collagen fibres that become exposed, and rough surfaces |
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Term
| These fibres are exposed when endothelium is broken |
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Definition
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Term
| Platelets grow these to adhere to blood vessels and other platelets |
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Definition
| Pseudopods - long and spiny |
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Term
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Definition
| A temporary projection of the cytoplasm of certain cells |
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Term
| This causes the walls of blood vessels to draw together during platelet plug formation |
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Definition
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Term
| Serotonin, ADP, and thromboxane A2 are released by what |
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Definition
| Platelets that are undergoing degranulation |
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Term
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Definition
| Exocytosis of cytoplasmic granules and release of factors that promote homeostasis |
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Term
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Definition
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Term
| The role of ADP in haemostasis |
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Definition
| Attracts more platelets to area and stimulates degranulation |
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Term
| The role of A2 in haemostasis |
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Definition
| It is an eiconsanoid - promotes plateletaggregation, degranulation, and vasoconstriction |
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Term
| The main objective of coagulation |
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Definition
| To convert fibrinogen into fibrin |
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Term
| What type of molecule is fibrinogen |
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Definition
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Term
| The two reaction pathways of coagulation |
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Definition
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Term
| The type of factors that initiate the extrinsic mechanism of coagulation |
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Definition
| Clotting factors released by damaged blood vessels and perivascular tissues |
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Term
| The type of factors that initiate the intrinsic mechanism of coagulation |
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Definition
| Only factors found in blood |
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Term
| The name given to clotting factors |
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Definition
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Term
| The lipoprotein mixture released by damaged blood vessels and perivascular tissue that initiates coagulation |
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Definition
| Tissue thromboplastin (factor III) |
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Term
| The next step in the completion of coagulation, after factor X has been activated |
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Definition
| Factor X combines with factors III and V in presence of Ca2+ and PF3 - produces thrombin activator |
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Term
| The effect of thrombin on fibrinogen |
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Definition
| Chops up fibrinogen into shorter strands of fibrin - becomes a dense aggregation called a fibrin polymer (framework of blood clot) |
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Term
| Which mechanism of coagulation has fewer steps to activate factor X |
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Definition
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Term
| Platelets and epithelial cells secrete this to stimulate cells to repair damaged blood vessels |
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Definition
| Platelet-derived growth factor (PDGF) - a mitotic stimulant |
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Term
| The type of chemical that platelet-derived growth factor is |
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Definition
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Term
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Definition
| The dissolution of a blood clot |
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Term
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Definition
| It is a fibrin dissolving enzyme |
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Term
| This plasma enzyme converts inactive protein plasminogen into plasmin |
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Definition
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Term
| True or false - Thrombin can activate plasmin |
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Definition
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Term
| True or false - Plasmin indirectly promotes the formation of more kallikrein |
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Definition
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Term
| The three things that prevent inappropriate clotting |
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Definition
| Platelet repulsion, Dilution, Anticoagulants |
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Term
| What chemical is normally too diluted in blood to make it clot inappropriately? |
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Definition
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Term
| The anticoagulants present in plasma that stop thrombin forming inappropriate clots in the blood |
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Definition
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Term
| Antithrombin is secreted from here |
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Definition
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Term
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Definition
| Interferes with promotion of prothrombin activator, blocks action of thrombin on fibrinogen and promotes action of anti fibrinogen |
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Term
| Heparin is secreted by these |
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Definition
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