2 - Thrombosis, Embolism, Infarction Flashcards
What is the term for the normal physiologic process of maintaining blood in a fluid, clot-free state in normal vessels while inducing a rapid and localized hemostatic plug at sites of vascular injury?
Hemostasis
What are the three major players in the process of hemostasis?
(1) Vascular endothelium (2) Platelets (3) The coagulation cascade
“Which of the following is/are not especially relevant in the process of hemostasis? (a) Albumin (b) Coagulation cascade (c) Fibroblasts (d) Platelets (e) Red blood cells (f) Vascular endothelium “
“(a) Albumin (c) Fibroblasts [remember that fibroblasts have NOTHING to do with fibrin or fibrinogen] (e) Red blood cells”
What is the correct term for a blood clot?
A thrombus
What are the components of a thrombus?
(1) Platelets
(2) Fibrin [circulating fibrinogen, produced by the liver, is polymerized during clotting to insoluble fibrin]
(3) Trapped red and white blood cells [mainly red cells, because they’re more numerous]
What is another term for a blood clot?
A thrombus
What is a thrombus?
A permanent hemostatic plug composed of a mesh of intermingled platelets, fibrin and entrapped blood cells. A “blood clot.”
What does the term thrombosis mean?
Inappropriate activation of blood clotting in an uninjured vessel or after minor injury
What is the term for inappropriate activation of blood clotting in an uninjured vessel or after minor injury?
Thrombosis
What are the three primary influences or inciting causes of thrombosis that comprise Virchow’s triad?
“(1) Endothelial injury (2) Alterations in normal blood flow (3) Hypercoagulability”
Of the three primary influences or inciting causes of thrombosis that comprise Virchow’s triad, which is the most important?
Endothelial injury
“Of the three components of Virchow’s triad, below, which is the most important? (1) Alterations in normal blood flow (2) Endothelial injury (3) Hypercoagulability”
(2) Endothelial injury
Give an example of something that could cause endothelial injury and predispose to thrombosis.
“There are many causes of endothelial injury such as: (1) Trauma [e.g., faulty IV injection] (2) Vasculitis [infectious organisms, immune-mediated] (3) Metabolic disorders [e.g., vitamin E deficiency] (4) Neoplasia (5) Toxins [e.g., bacterial endotoxin]”
“Of the three components of Virchow’s triad, below, which is the SECOND most important? (1) Alterations in normal blood flow (2) Endothelial injury (3) Hypercoagulability”
(1) Alterations in normal blood flow
Is STASIS of blood a more common cause of thrombosis in arteries or in veins?
Veins
Is TURBULENCE of blood a more common cause of thrombosis in arteries or in veins?
Arteries
List FOUR ways in which abnormal blood flow in a vessel can predispose to thrombosis.
“Both stasis and turbulence: (1) disrupt laminar flow, bringing platelets into contact with endothelium (2) prevent dilution of activated clotting factors by fresh flowing blood (3) retard the inflow of clotting factor inhibitors and permit build-up of thrombi (4) promote endothelial cell activation (which makes endothelial cells “sticky”)”
What is the most common cause of hypercoagulability?
Inflammation
What is the definition of hypercoagulability?
Any alteration of the coagulation pathways that predisposes to thrombosis
Which type of thrombus (arterial or venous) is more likely to be occlusive (i.e., fully block a vessel)?
Venous
Which type of thrombus (arterial or venous) is more likely to be red and gelatinous?
Venous