Thrombosis and Embolism

Thrombosis Thrombus: a blood clot occurring in a vessel or the heart solid mass of platelets and / or fibrin can occlude a vessel resulting in anoxic death of cells term applied to cell death

Infarction tissue that has been starved of oxygen resulting in tissue death What would you call heart tissue deprived of oxygen resulting in death? Myocardial Infarction (heart attack) For individuals who suffer a first time heart attack, 50% are fatal

Ischemia: tissue that has been starved of oxygen, but had not yet died It is possible to reverse ischemia with clot dissolving drugs

Thrombus

Thrombus and Embolus

What Causes the Formation of a Thrombus? Atherosclerosis

Vascular injury injury to the endothelium of a blood vessel can cause a clot Why? When an injury occurs, platelets stick to each other and form a clot Platelets solid, circulating cell fragments that are vital to stopping bleeds

Platelets

Causes of Vascular Injury Phlebitis inflammation of veins caused by lack of blood flow causes: chemical injury traumatic injury bacterial injury

Phlebitis

Causes of Vascular Injury Blood flow any change in blood flow turbulence contributes to the thrombosis by bringing solid parts of the blood into contact with endothelial surface major areas affected by blood flow that may result in a thrombus: 1.) Plasmatic zone Along the tunica intima there is a layer of just plasma Purpose: to keep solids from hitting the lumen’s wall Why?

Provides a buffer so rbcs, wbcs, and platelets do not hit the wall

2.) Valves Large veins can become stretched out and not function properly Stretched out valves cause turbulence of blood—not good

Thrombus Caused by a Valve

Blood Flow Changes 3.) Varicose veins valves malfunction blood remains causing veins to become enlarged and twisted

Varicose Veins due to pregnancy standing for extending periods of time being over weight increases with age

4.) Hypercoagulability spontaneous blood clot reason is not always known #1 cause female smokers who take birth control pills

Location of Thrombi Can occur anywhere in the cardiovascular system Mural thrombi form in the heart Occlusive thrombi form in the lumen of the vessels

Treatment of Thrombi 1.) Clot dissolving drugs Break up the clot and, hopefully, prevent a myocardial infarction or stroke Without the drugs: Necrosis of the thrombus occurs (after several days) Tissue damage will occur as a result of the infarction Two of the common clot dissolving drugs: Streptokinase tPA tissue plasminogen activator These can halt the progression of ischemia

Embolism Embolism: Embolus: the occlusion of a vessel by a foreign mass traveling through the blood system May arise in arteries and veins Embolus: a blood clot that has ruptured or broken up and flows with the blood until it lodges or dissolves

Causes of Emboli Thrombus (main cause) Undissolved air or gas bubbles in the blood stream Tumor fragments Bone fragments

Venuous Emboli Most arise from thrombi in the legs Called deep vein thrombosis (if forms in the deeper veins of the legs or pelvis) May cause warmth, swelling, pain near the affected vessels

Venous Emboli

Venous Emboli If the thrombus travel towards the heart: Pass through the right side of the heart and into the lungs Can occlude a vessel in the lungs resulting in pulmonary hemorrhage or pulmonary infarction

Pulmonary Embolism

Pulmonary Embolism

Pulmonary Infarction Blood clot in the lungs When no blood reaches a section of the lung, that portion of the lung suffers an infarction meaning it dies because no blood or oxygen is reaching it

Arterial Emboli Usually form from thrombi in the aorta or heart Travel away from the heart into smaller arteries Areas most commonly affected heart brain lower extremities kidneys spleen

Arterial Embolism

Lab Aorta Clear

For Lab