Hemodynamic Disorders 2

crbvi's version from 2017-05-24 19:05

Section 1

Question Answer
Thrombosisprocess of formation of thrombus
What is a thrombus? it is a solid intravascular mass attached to the vess wall
Thrombus is formed ____ and from constituents of the ___- during life - blood
Microscopic appearance of Thrombuseosinophilic masses that contain RBCs,WBCs, fibrin and platelets
Gross appearance of a thrombusmass attached to the vessel wall, can be red or gray, dry and friable, surface is granular and rough
____ are red thromib and are formed slowlyvenous thrombi
____ are gray-white thrombi and are composed of a tangled mesh of platelets and fibrinarterial thrombi
Thromibi grossly and microscopically have apparent laminations called ____lines of Zahn
Lines of Zahn signify that a thrombus has formed in _____ and can distinguish ____ from the ____ that occur postmorteum- flowing blood - antermortem thrombosis - bland nonlaminated clots

Section 2

Question Answer
Mural thrombiattached to a part of the wall of the blood vessel or heart
Occluding thrombi they fill the lumen comlpletely
Valvular Thrombiare attached to the heart valves and are also termed vegetation
Canalized Thrombioccur when new blood channels form in an organized thromnus
Saddle Thrombusstraddle the bifurcation of blood vessels
Septic Thrombiare those that contain microorganisms

Section 3

Question Answer
What are the 3 Factors that the pathogenesis of thrombosis involves? this is the famous ____1. Endothelial Injury 2. Alterations in blood flow 3. Hypercoagulability "Virchow Triad"
Clinical circumstances of endothelial cell injury (2)1. Atherosclerotic Plaques when they break open 2. Hypertension **** THESE ARE THE MOST COMMON CAUSES OF THROMBOSIS
What explains the reason why thrombosis is much MORE FREQUENT in VEINS rather that in arteries- because blood flows slower through the veins which gives platelets a better chance to stick and clotting factors a better chance to act
___ and ___ are MAJOR FACTORS in the development of VENOUS THROMBI (red thrombi)Turbulence and Stasis
Examples of alternations in blood flow leading to thrombosis"Varicose Veins" = distended veins cause stagnation of blood flow --> Thrombi - Abnormal vasular dilations (ANEURYSMS) and Plaques causes turbulence
Hypercoagulability alteration of the coagulation pathways that predisposes to thrombosis also called THROMBOTIC DIATHESIS
Inherited Reasons of Hypercoagulability - Leiden mutation (Factor V gene) - Hyperhomocysteinemia - Deficiency of anticoagulants
Acquired Reasons of Hypercoagulability - Prolonged bed rest - oral contraceptive - hyperestrogenic state (prego) - heparin-induced - antiphospholipid ab

Section 4

Question Answer
Fate of a thrombus _________ & ___Growth and propagation
Fate of a thrombus where it breaks off = Embolization
Fate of a thrombus where is dissolved by the fibronolytic activity of blood =Dissolution
Fate of a thrombus = process by which the thrombus is invaded by cellular elements and fibrosis ultimately occurs and new blood vessels grow Organization and Recanalization

Section 5

Question Answer
Example of Venous Thrombi Deep Vein Thrombosis (in deep veins of lower extremity)
Most common mechanism of DVTactivation of coagulation in areas of sluggish blood flow and venous stasis
Consequences of DVTsuperficial veins - local congestion deep - deep veins - danger of pul thromboembolism
Majority of arterial thrombi overlie _____ and the most common cause is ____ ____ which induces platelet aggregation- atherosclerotic plaques - endothelial cell injury
____ arise in the setting of myocardial infarction related to dyskinetic contraction of the myocardium- Cardiac Mural Thrombi
_____ results in mitral valve stenosis followed by left atrial dilation and atrial mural thrombi- Rheumatic Heart Disease
Target organs of arterial thrombi _________,_________,and__- brain - kidney -spleen because of their rich blood supply
Warfarin and heparin prevent what?- formation of venous thrombi
_____ is caused by arterial thrombi- coronary artery artherosclerosis
_____ are inhibitors of platelet formation- Aspirin

Section 6

Question Answer
solid, liquid or gaseous objects carried in the blood and that are large enough to beome impacted in the downstream lumen Embolism
Almost all emboli represent _____ hence the commonly used term ____- some part of a dislodged thrombus - thromboembolism
Consequence of embolism = - infarct with ischemic necrosis
What are the rare forms of emboli?- fat embolism - atheromatous emboli - bone marrow - parasites - foreign bodies - gas embolism - amniotic fluid embolism
Where is an embolus likely to become impacted? Arising from the peripheral veins end in the ____. Arising in arterial blood end up in ___- lungs - arteries

Section 7

Question Answer
blockage of the pulmonary artery when a venous thrombus become dislodgedPul embolism
Where do the most thromboemboli arise from?deep veins of the thigh and from the popliteal vein (deep venous thrombosis)
Variable clinical finding in pul thromboembolismasymptomatic small pulmonary emboli, chronic pulmonary embolism (may lead to pul hypertension & rt sided heart failure), pul infarction

Section 8

Question Answer
emboli tarveling within the arterial circulationsystemic thromboembolism
Etiology of Systemic Thromboembolism 1. Thrombi from the left side of heart (mitral stenosis) (valvular vegetations) 2. Thrombi from aorta and its branches (aortic aneurysms) (ulcerated atherosclerotic plaques) (Paradoxial Emboli - found within the arterial circulation)
Sites of embolism of systemic thrombembolism1. lower extremities 2. Brain 3. Bowel Infarction 4. Renal or Splenic Infarcts

Section 9

Question Answer
arise in the systemic veins but instead of ending in the lungs they embolize to the system arteries and are RARE Paradoxical Embolism
Paradoxical Embolism bypass the lung in 2 ways:1. Large emboil pass through a vertricular septal defect or a patent foramen ovale 2. Small emboli pass through the arteriovenous shunts