medical

• Dermatology is the branch of medicine that focuses on the diagnosis and treatment of skin, hair, and nail disorders.
• Hemostasis, Coagulation, and Hemostasis are complex physiological processes that aim to prevent and stop blood from leaking out of our blood vessels.
• Hemostasis involves cells, soluble and insoluble proteins.
• Hemostasis is a process that retains the blood within the vascular system during periods of injury, localizes the reaction involved in the site of injury, and repairs and re-establishes blood flow through the injured vessel.
• FSP/FDP (+) → DIC or pathological fibrinolysis.
• Plasmin will also lyse fibrinogen, but will not produce D-dimmer.
• FDP( +) ; D-dimmer (+) → DIC.
• Plasmin lyses the fibrin and produces FDP that contains the portion called as “D-dimmer”.
• The presence of D-dimmer indicates that a stable fibrin clot has been lysed.
• FDP (+) ; D-dimmer (-) → pathological fibrinolysis.
• Hemostasis achieves balance through the process of balancing bleeding (hemorrhage) and clotting (thrombosis).
• The three hemostatic components are the Extravascular Component, the Vascular Component, and the Intravascular Component.
• The Extravascular Component involves the tissues surrounding a vessel and its ability to aid in hemostasis depends on the bulk or amount of surrounding tissue, the type of tissue surrounding the injured vessel, and the tone surrounding tissue.
• The Vascular Component involves the blood vessels in which the blood flows, including capillaries, arteries, and veins.
• Substances released from or found on the surface of intact endothelial cells include Prostacyclin (PGI2), ATP, Thrombomodulin, Heparan Sulfate, Tissue plasminogen activator (tPA), and Von Willevbrand factor (vWF).
• The Intravascular Component is a key component in intravascular hemostasis and involves platelets and biochemical (procoagulants) in the plasma.
• Bridges formed by fibrinogen in the presence of calcium produce a sticky surface on platelets, reinforcing the aggregates and referring to them as a thrombus.
• Fibrinogen, under the influence of small amounts of thrombin, provides the basis for consolidation and stabilization, involving the precipitation of polymerized fibrin around each platelet, resulting in a fibrin clot that produces an irreversible platelet plug.
• Platelet granules move to the center of the platelets and fuse with the open canalicular system connected to the outside of the platelet, resulting in the extrusion of the granules' content to the outside.
• Platelet aggregation involves the simultaneous release of platelets and the binding of platelet stimulating agents such as collagen, ADP, epinephrine, and thrombin, causing the platelets to adhere to one another.
• Hematology involves the study of blood, including coagulation.
• After activation, platelets undergo a shape change caused by contraction of the disk shape into a spherical shape with the extrusion of numerous pseudopods.
• Fibrinogen binds to receptors on adjacent platelets and joins them together in the presence of fibrinogen, which is necessary as a cofactor for platelet aggregation.
• Platelet activation involves a change in platelets that occurs when they metabolize arachidonic acid to form prostaglandin endoperoxides, which are converted to thromboxane A2.
• Cyclooxygenase inhibits the cyclooxygenase pathway.
• Thrombocytes, or platelets, have a diameter of 2 to 4 um (1 to 4 um) and a volume approximately 6 to 7.5 fL.
• Thrombocytes are disk-shaped and have a light violet-purple granular appearance when stained with Wright’s stain.
• The average counts of thrombocytes are slightly higher in women than in men.
• Thrombocytes are distributed throughout the red blood cell monolayer in a Wright-stained blood smear.
• Thrombocytopenia is a condition where platelet count is below the normal range, which can be due to thrombocytopenia purpura, aplastic anemia, acute leukemia, pernicious anemia, Gaucher’s disease.
• Platelet Rich Plasma (PRP) contains 200,000 to 300,000 platelets (200 to 300 x109/L platelets) and is used for platelet aggregometry or platelet function test.
• Squares counted in a blood smear are 25/25 squares or 10 tertiary squares of the center square.
• Thrombocytosis is a condition where platelet count is above the normal range, which can be due to PV, idiopathic thrombcythemia, CML, splenectomy.
• Dilution is a condition where platelet count is less than 1:100.
• The size of glass test tube used for PT and APTT is 12 x75mm.
• Increased D-Dimer and Fibrin Monomer levels indicate DIC (uncontrolled).
• Decreased platelet count is a symptom of DIC (uncontrolled).
• DIC (uncontrolled) can lead to hemorrhage due to inappropriate formation of fibrin within the blood vessels.
• Normal platelet count range is 150 - 400 x10 9 /L or 150 to 450 x10 9 (Rodak's).
• Normal platelet count is a key factor in hemostasis.