HEMA 2 | CHAP 10

• The platelet membrane contains more than 50 distinct receptors what is the most significant?

  Cell Adhesion Molecules (CAM) integrin family
• Members of CAM family where GP Ib/IX/V belong?

  leucine-rich-repeat family CAM
• What heterodimer depend on the collagen binding to GP VI?

  GP Ia/IIa ; alpha 2 beta 1
• Are also known as stress platelets that compnesates for thrombocytopenia.

  Reticulated platelets
• A transcription factor that mediates the switch from mitosis to endomitosis

  RUNX1
• This signaling receptors for ADP

  P2Y1 and P2Y12
• ADAMST13 is responsible for?

  VWF cleavage
• Platelet tethering is the attachment of platelets to the surface of the vessel wall, what binding is responsible for this?

  Glycoprotein Ib-IX-V complex.
• A type of signaling that deceases in cyclic adenosine monophosphate and supports that formation of irreversible platelet aggregates?

  P2Y12 signaling
• A membrane receptor present all throughout the platelet maturation

  MPL
• CD34 is a marker for what stages of platelet development?

  Early stages or progenitor stages
• True or False

  IL3 is a cytokine that has a therapeutic agent for chronic immune thrombocytopenic purpura and is present in throbocytopoiesis.

  False
• GP VI binds to collagen that triggers activation of GP Ia/IIa
• Megakaryoblasts or MK I are distinguished in the presence of blebs.
• The neutral phospholipids that predominate the outer blood plasma layer are called phosphatidylcholine and sphingomyelin.
• A type of signaling increases intracellular calcium levels and initiate initial platelet activation, shape changes, and formation of small reversible aggregate?

  P2Y1
• How are neighboring platelets activated and trigger inside out reaction?

  Due to the production of TXA2 and the release of ADP
• Megakaryocytes respond to what growth factor?

  Thrombopoietin
• The least mature progenitor stage?

  Burst-forming-unit (BFU-Meg)
• What stage progenitor stage is LD-CFU-Meg characterized as?

  More mature progenitor stage
• A form of mitosis that lacks telophase and cytokinesis

  Endomitosis
• What progenitor stage undergoes endomitosis?

  LD-CFU-Meg
• The cofactor that regulates GATA-1

  FOG1
• Intermediate progenitor stage.

  CFU-Meg
• Transcription gene product that suppresses GATA-1 and FOG1 that balances megakaryocytopoiesis with erythropoiesis

  MYB
• Ligands or agonists are responsible for?

  receptors for that respond to cellular and humoral stimuli
• Responsible for inside out signaling mechanism

  alpha IIb beta 3
• alpha IIb beta 3bgenerates and interplatelet cohesion called.

  Platelet Aggregation
• A type of clot that contains fibrin and RBC that deposit around and within platelets.

  Red clot
• White clots are composed primarily of platelets and VWF
• Allows platelets to cover more surface and enhances binding to foreign surfaces and other platelets.

  Pseudopods
• Most abundant micro-particles in the circulation?

  platelet microparticles
• Elevated levels of intracellular calcium results in what?

  Cellular signaling and various physiological responses.
• Triggers the production of thrombin that cleaves platelet PAR1 and PAR4.

  Tissue factor
• alpha -beta- gamma heterodimers that bind GDP

  G-proteins
• Where does G-protien bind when inactive?

  GDP
• Part of the G molecule that hydrolyzes the bound GTP to GDP


  G alpha portion
• What pathway does the hydrolysis step of G proteins trigger?

  Eicosanoid synthesis or IP3-DAG pathway
• A type of phospholipid that binds to arachidonic acid?

  Phosphatidylinositol
• Phospholipase A2 is triggered by G-protein activation.