8th lecture (embolisim, thrombus) Flashcards
what is thrombosis?
pathological form of homeostasis
steps of hemostasis?
- endothelial cell injury, release of substances causing vasospasms which slow down circulation.
- adhesion of platelets to exposed area where endothelial cells are missing.
- activation of fibrin and polymerization of fibrin
- thrombomodulin stops coagulation cascade to form stable hemostatic plug.
what are the virchowian trials (Rudolf virchow, famous German pathologist)
The 3 factors for thrombosus.
- endothelial lesions: the hemostatic plug itself can generate thrombosus, thus anything that causes trauma to endothelium can cause thrombosus. Vasculitits can do this
- Altered blood flow: Turbulence do to aneurysm which causes endothelial injury. stasis of the blood can also do this, since blood stasis generates hypercoagulability since coagulation factors are not being washed out with lamina blood flow, removing factors and platelets.
- hypercoagulability: more chances to coagulate the blood, could be primary or could be secondary:
Primary = genetics (laiden mutation to factor V, or mutation of prothrombin gene)
Secondary = Flow?
Morphology of a thrombosis?
- White thrombus (sedimentation thrombus): endothelial injury that cause mostly platelets to coagulate.
- Red thrombus: Coagulated blood (characteristic for venous thrombus) the blood coagulates as it is making a “cast”
- composite thrombus: white head and red tail. this is do to the initial white thrombus forming in the artery and a stasis forms behind the thrombus causing it to propagate with a red tail.
- Laminated thrombus: characteristic for aneurysm since in aneurysm has 2 factors, the dilation is caused by endothelial injuries (atherosclerosis, M.I.) and the other is the stasis or turbulent blood flow in an area. The blood flow can fluctuate between static or turbulent blood flow, making a layers white-red-white-red areas making LINES OF ZAHN
- DIC: disseminated intravascular coagulation (small parts of coagulated blood floating in the blood)
what is line of Zahn of thrombus?
alternating layers (laminations) of platelets mixed with fibrin, which appear lighter and darker layers of red blood cells. This forms a laminated thrombus that is made up of layers of white and red thrombus.
Localization of the thrombus?
A/ Mural thrombus -atrial -ventricular -valves B/ arterial thrombus -Atherosclerosis -Aneyrisim (exclusion from laminal flow) -Vasculitis C/ Venous thrombus (phlebothrombosis) -Vena femoralis -periprostatic -parametric -portal
Describe the mural thrombus? (related to the heart)
Thrombus is located in the atria:
-mitral stenosis causing stasis of the blood in the atria
-arrhythmia absolute and this causes stasis of blood in atria do to the lack of contraction in the atria
-auricles of the atrial are excluded from the circulation, thus this is most typical place for atrial thrombus.
Ventricular thrombus:
-caused by the aftermath of a myocardial infraction, the paradox pulsation caused dilation of a certain area of the heart. The area becomes fibrotic and stasis of blood occurs in the area making it thrombogenic.
-Valves:
vegetation of the valve; when the valve have aggregation of platelets and RBC and endocarditis.
Describe the arterial thrombus?
- atherosclerosis: since the plaque may ulcerate and forming a thrombogenic surface.
- aneyrisim: any are where the blood is excluded from laminar flow of the circulation, stasis, turbulence flow, and thrombogenic surface.
- vasculitis: inflammation of the vessels may initiate thrombus.
describe venous thrombus (phlebothrombosis)?
These are usually re-thrombus, with a cast-like red coagulate. Characteristic for the vena-femoralis during long periods of inactivity of legs, do to lack of muscle pump.
- Peri-prostatic: prostate hyperplasia compresses the vein flow of the peri-prostatic veins do to stasis.
- parametric (in pregnant women) the fetus may block the parametrial venous circulation causing thrombosis
- portal vein; cirrhosis causing the blocking of the portal veni resulting in coagulation in the portal vein.
what classes of thrombus are usually (but no always) found in what kindof vessel?
- Artery = white thrombus
- Veins = red thrombus
- systemic circulation = composite thrombus.
FATE of the thrombus (what may happen to the thrombus)?
- propagation: thrombus may grow do to the stasis of the blood behind it
- embolism: Thrombus that partly or completely detaches
- organization: Fibroblasts may grow into the thrombus and fibrosis occurs and occlude/organize the fibrotic tissue
- recanalization: endothelial cells in-grow into the thrombus making small capillaries through the thrombus, the capillaries may fuse and make a new channel.
- thrombolysis: Thrombolytic activity dissolve the thrombus
Describe the Clinical aspects of thrombosus?
A/ venous thrombus 1. superficial artery femoralis 2.deep vein femoral 3. parametric 4. periprostatic 5. vena-portae B/ Cardiac 1. Atraial 2. Ventricular 3. Valvular C/ Arterial 1. arteriosclerosis 2. aneurysm
Describe venous thrombus clinical aspects? (5 total)
- superficial artery femoralis (superficial arteries under skin which may develop thrombosis if varicosities are present since they slow down/stasis of blood occurs. (THIS is not dangerous since they cannot provide pulmonary embolism)
- deep vein femoral (deep vein thrombosis do to inactivity) Inactivity in the legs also causes Edema since there is a lack of outflow.
- parametric; (in pregnant women) the fetus may block the parametrial venous circulation causing thrombosis
- periprostatic: prostate hyperplasia compresses the vein flow of the peri-prostatic veins do to stasis.
- vena-portae: cyrosis causing the blocking of the portal veni resulting in coagulation in the portal vein.
Describe the cardiac thrombus clinical aspects? (3 total)
thrombus could come from the:
- atrial (arrhythmia absolute OR mitral stenosis)
- ventricular (myocardial infraction)
- valvular: vegetation of the valve; when the valve have aggregation of platelets and RBC and endocarditis.
Describe arterial thrombosis clinical aspects? (2 total)
- atherosclerosis
2. aneurysm
Describe DIC?
Disseminated intravascular coagulation is a condition in which small blood clots develop throughout the bloodstream, blocking small blood vessels
what conditions generate the coagulation seen in DIC?
A/ obstetic 1. fetus mortis 2. abruptio placentae 3. amnionic fluid embolisim 4. septic abortion B/ Infection 1. sepsis (patients in trauma unit) 2. meningococcal infection C/ trauma 1. "car crash" D/ burns E/ neoplasm
Define obstetic?
relating to childbirth and the processes associated with it.
Obstetic DIC (disseminated intravascular coagulation) examples? (4 total).
A/ obstetic
- fetus mortis: (dead fetus in the mother, and the dissolution of the cells causes tissue factors to be squeezed into the circulation, causing coagulation)
- abruptio placentae: (placenta separation caused bleeding and tissue necrosis causing tissue factors to get into the circulation, forming the clot)
- amniotic fluid embolism (during placenta separation the amniotic fluid/cells can get into the circulation and cause coagulation via tissue factors)
- septic abortion: termination of the pregnancy may leave some fetal tissues in the uterus. This is a source for infection causes sepsis and tissue factor release.
Infection DIC examples?
disseminated intravascular coagulation
B/ infection
- Bacteria is in the circulation: The bacteria release toxins and substances that activate coagulation. The infection can also damage the endothelial cells.
- meningococcal infection
Trauma causing DIC examples? (disseminated intravascular coagulation)
C/ trauma
Crash syndrome; (car crash) the squeezing of the body squeezing the cells which release factors activating coagulation.
Burns causing DIC examples? (disseminated intravascular coagulation)
D/ Burn
- Damage to the cells causing the tissue factors to be squeezed out into the circulation.
Neoplasm causing DIC examples? (disseminated intravascular coagulation)
E/ neoplasm
certain neoplasms create pro-coagulant factors. Especially adenocarcinoma that produce mucin which has a factor for coagulation of the blood. Examples of this are: Pancreatic and stomach caner.
what are the consequences of DIC (disseminated intravascular coagulation)
(2 total)
- thrombosus/ebolisim/ischemia
(lung is most affected as the capillaries are obliterated, Kidney failure as capillaries are obstructed, Neurological problems (brain) could also occur if capillaries in brain are clogged. - bleeding do to DIC using up the platelets and coagulation factors. (very dangerous).
Consumption coagulopathy.
