HEMATOLOGY 2

• Area within the platelet that is responsible for platelet adhesion and aggregation

  Peripheral zone
• Size of megakaryocyte (MK-III)

  30-50 um
• Vascular layer with antithrombotic property

  Tunica intima
• Vascular layer that produces molecules to promote platelet activation and adhesion

  Tunica adventitia
• If EPO is produced by the kidney, TPO is mainly produced by the:

  LIVER
• Receptor protein for binding of VWF. Important for adhesion.

  Glycoprotein Ib/IX/V
• Binding site for fibrinogen. Important for aggregation.

  Gp IIb/IIIa
• Glycoprotein that serves as thrombin substrate.

  Glycoprotein V
• Glycoprotein that serves as key collagen receptor.

  Glycoprotein VI
• Neutral phospholipids that predominantes the outer layer of platelet plasma membrane.

  Phosphatidylcholine and Spingomyelin
• Polar phospholipids that predominates the inner layer of platelet plasma membrane.

  Phosphatidylinositol, Phosphatidylethanolamine, and Phosphatidylserine
• Phospholipid that supports platelet activation by supplying arachidonic acid.

  Phosphatidylinositol
• Phospholipid that serves as the assemply point of coagulation factors because it flips to the outer surface upon platelet activation.

  Phosphatidylserine
• Platelet zone that interacts with the dense tubular system in sequestering calcium.

  Structural zone or Sol-gel zone
• Area of the platelet that encompasses the alpha granules, dense granules, and lysosomes.

  Organelle zone
• Route for endocytosis and secretion of alpha and lysosomal granules upon activation.

  OPEN CANALICULAR SYSTEM or SURFACE-CONNECTED CANALICULAR SYSTEM
• What area of the platelet is responsible for storing/sequestering calcium?

  DENSE TUBULAR SYSTEM
• Contains phospholipase A2, cyclooxygenase, and thromboxane synthase, which are enzymes responsible for platelet activation.

  DENSE TUBULAR SYSTEM
• Control center for platelet activation.

  DENSE TUBULAR SYSTEM
• Damaged endothelial cells will release -blank- that will be necessary for platelet adhesion.

  VWF
• The circulating VWF is in the form of?

  Globular protein
• The activated VWF is in the form of?

  Fibrillar protein
• Platelet granules that serve as coagulant proteins.

  ALPHA GRANULES
• Platelet granules that serve as vasocontrictors.

  DENSE GRANULES
• Vascular defect due to degeneration of COLLAGEN leading to bruised areas on the forearm (occurs in the ELDERLY).

  PURPURA SENILIS
• Vascular defect that affects small vessels. Acute respiratory infection precedes the purpura in a high proportion of affected young children.

  Henoch-Schoenlein Purpura/Allergic Purpura/Non-thrombocytopenic Purpura
• The most common vascular disorder due to bleeding from visible congenital vascular malformations.

  Hereditary Hemorrhagic Telangiectasia/Osler-Weber-Rendu Disease
• Vascular disorder due to extensive DIFFUSE hemorrhage into the SOFT TISSUES of the EXTREMITIES. It often follows a streptococcal infection and related to Factor V deficiency.

  PURPURA FULMINANS
• What is the average size of thrombocytes/platelets

  1-4 um
• A single megakaryocyte may shed 2000-4000 platelets.
• Normal range of Mean Platelet Volume (MPV).

  6.8 to 10.2 fL
• NC ratio of Megakaryoblast (MK-1)

  3:1
• NC ratio of Promegakaryocyte (MK-II)

  1:2
• NC ratio of Megakaryocyte (MK-III)

  1:4
• All coagulation factors except fibrinogen are either enzyme pre-cursors or cofactors.
• All enzymes except Factor XIII (transglutaminase) are serine proteases, which are capable of hydrolyzing peptide bonds.
• Plasma concentration of fibrinogen

  200-400 mg/dL
• Laki-lorand factor

  Factor XIII
• Fletcher factor

  Prekallikrein
• Fitzgerald factor

  HMWK