Thrombosis and Embolism Lecture

Vocabulary practice flashcards covering circulatory disturbances, including the mechanisms, morphology, and fates of thrombosis and various types of emboli.

Thrombosis

The formation of an aggregate mass of platelets, fibrin, and red blood cells that accumulates and adheres to the inner wall of a blood vessel.

Embolus

A detached intravascular physical mass, such as a thrombus fragment, fat droplet, gas bubble, or tissue fragment, that travels through the bloodstream to lodge at a distant site.

Virchow's Triad

The three primary pathophysiologic abnormalities predisposing to thrombus formation: endothelial injury, hypercoagulability, and alterations in normal blood flow (stasis or turbulence).

Alabama Rot

A breed-specific disease seen in Greyhounds characterized by endothelial injury leading to cutaneous and glomerular vasculopathy.

Lines of Zahn

Microscopic laminations consisting of alternating pale layers of platelets and fibrin mixed with darker layers of erythrocytes, which diagnostically confirm that a thrombus formed antemortem in flowing blood.

Arterial Thrombi

Firm, pale, dull thrombi formed under high shear and rapid flow conditions, adhering firmly to the vascular intima and consisting predominantly of platelets and fibrin.

Venous Thrombi

Dark red, soft, jelly-like thrombi formed in low-shear, sluggish flow environments, rich in red blood cells trapped in fibrin networks and typically propagating upstream toward the heart.

Chicken Fat Clot

A colloquial term for a pale yellow, gelatinous postmortem blood clot that forms when erythrocytes settle out by gravity before blood coagulates without vessel wall attachment.

Mural Thrombi

Thrombi that adhere directly to the endothelial lining of cardiac chambers or the walls of large vessels, often caused by abnormal myocardial contraction, endocardial injury, or arrhythmias.

Valvular Vegetation

Large, friable thrombotic masses attached to heart valves that can be sterile or septic, frequently resulting from endothelial erosion associated with bacteremia or fungemia.

Recanalization

The reparative process by which fibroblasts and endothelial cells invade a persistent, organized thrombus to establish new vascular channels that restore partial blood flow.

Saddle Thrombus

A thromboembolism in cats secondary to hypertrophic cardiomyopathy that lodges at the terminal aortic bifurcation into the iliac arteries, resulting in sudden hindlimb paralysis, cold extremities, and severe pain.

Fat Embolism

The vascular occlusion caused by circulating globules of adipose tissue and bone marrow released following bone trauma or fractures, most commonly lodging within pulmonary capillaries.

Fibrocartilaginous Embolism

The migration of degenerate intervertebral disc material into adjacent spinal vessels following disc extrusion, leading to local ischemic spinal cord infarction.

The Bends

A manifestation of decompression sickness wherein dissolved nitrogen rapidly comes out of blood and tissue solution to form microbubbles in musculoskeletal tissues, resulting in excruciating joint pain.

The Chokes

A severe pulmonary manifestation of decompression gas embolism caused by gas microbubbles occluding the pulmonary microvasculature, leading to dyspnea, substernal pain, and pulmonary edema.

Antithrombin III Deficiency

A hypercoagulable state caused by the excessive urinary loss of the anticoagulant protein Antithrombin III through damaged glomeruli in protein-losing nephropathies or nephrotic syndrome.