thrombi and emboli Flashcards
what is laminar flow
when cells do not touch the cell wall
what is thrombosis
solid mass of blood constituents formed within intact vascular system during life
Virchows triad
Stasis of blood flow
Endothelial injury
Hyper coagulability
factors that attribute to increased coagulability
sepsis
smoking
coagulation disorders
malignancy
factors that attribute to reduced blood flow
Atrial fibrilation
long distance travel
varicose veins
venous obstruction
immobility
ventricular/ venous insufficiency
what can cause damage to vessel wall
trauma
orthopaedic surgeries
hypertension
invasive procedures
How does an arterial thrombosis occur
1- atheromatous plaque may have a fatty streak
2- over time the plaque grows and protrudes into the lumen causing turbulence in blood flow
3- results in loss of intimal cells
4- fibrin deposition and platelet clumping occurs
what part of VT is deep vein thrombosis
change in blood flow
define embolus
mass of material in the vascular system
able to become lodged within vessel and block it
what is ischaemia
reduction in blood flow to a tissue or part of the body caused by constriction or blockage
without any order complications
what is infarction
reduction in blood flow with subsequent death of cells
if an embolus was to enter the venous system what will happen
it will travel to the vena cava , through the right side of the heart and will lodge in the pulmonary arteries
cause a pulmonary embolism
what is infarction usually caused by
thrombosis of an artery
role of platelets in thrombus formation
alpha granules- for adhesion
dense granules- for aggregation
platelets are activated releasing their granules when they come into contact with collagen
If this happens within an intact vessel a thrombus is formed
Most likely cause of an embolism
Thrombus
why are tissues with an end arterial supply more susceptible to infarction
single arterial supply and so if this vessel is interrupted infarction is likely.
Define abscess
Acute inflammation with a fibrotic wall
give 3 examples of organs with a dual arterial supply
lungs
liver
Kidneys
difference between arterial and venous thrombosis
-lower BP in veins and atheroma do not occur
-thrombi begin at valves
-valves produce a degree of turbulence and can be damaged
clinical features of arterial thrombi
loss of pulse to distal thrombus
area becomes cold , pale and painful
possible gangrene
clinical presentation of venous thrombi
tender
area becomes red and swollen
Fate of thrombi
1- resolve
2-organised
3-recanalisation
4- embolus
What would you give to someone with an arterial thrombus
Aspirin
What would you give to someone with a venous thrombus
Direct oral anti coagulants
Warfarin
Types of thrombus
Pale , red and mixed
What is the composition of pale / white thrombus
Rich in fibrin with platelets
Composition of red thrombus
Mostly rbcs with less fibrin
What would histology show for an embolus
Lines of zahn
Alternating clot layers or red and pale thrombus
a large emboli can result in …?
acute respiratory or cardiac problems- pe
result in chest pain and shortness of breath
