Hemodyanmic Disorders II Flashcards
Hyperemia
active process in which arteriolar dilation results in increased flow of blood to a tissue
congestion
passive process due to impaired outflow of blood from a tissue
chronic passive congestion
long term congestino producing stasis of poorly oxygenated blood resulting in cellular degeneration and death
What happens if there is capillary rupture
small foci of hemorrhage
accumulation of hemosiderin-laden macrophages at site
what does acute pulomary congestion look like microscopically
alveolar capillaries engorged with blood
alveolar septal edema
focal intraalveolar hemorrhage
What does chronic pulmonary congestion look like microscopically
thicken and fibrotic septa
hemosiderin-laden macrophages in alveolar spaces
Nutmeg liver
central regions of hepatic lobules are grossly red/brown and depressed, surrounded by unaffected areas
centrilobular necrosis
hepatocellular death and accompanying hemorrhage with hemosiderin laden macrophage
hematoma
collection of blood
petechiae
1-2 mm hemorrhage
purura
> 3mm hemorrhage
ecchymoses
> 1-2 cm hemorrhage
What 3 general components contribute to hemostatis
endothelium/vascular wall
platlets
coagulation cascade
sequence of clot formation
- brief vasoconstriction
- platlets become activated and adhere
- tissue factor is released and activates the coagulation cascade forming fibrin
- platelet activation furthers coagulation
- fibrin and platelets form a clot
what type of functions does endothelium have
both anticoagulant and procoagulant
What can activate endothelium to procoagulant state
infectious agents
hemodynamic forces
cytokines
plasma mediators
what can activate endothelium to anticoagulant state
PGI2, NO
adenosine diphosphatase
thrombomodulin
converts thrombin to an anticogulatic
fivrinolytic
endothelial cells make tPA
what type of cell synthesizes von willebrand factor
endothelial
what induces endothelial cells to make tissue factor
endotoxin and some cytokines
what kind of cells secrete plasminogen activator inhibitor
endothelial
von willebrand factor
links subendothelium to glycoprotein Ib receptors on platelets
function of vWF
firm adherence of platelets to vessel wall
once platelets adhere to the wall what happens
release of their granules
What granule contents do platelets release
calcium
ADP
platelet factor 4
serotonin
_____ is critical for coagulation cascade
calcium
ADP
mediates platelets aggregation which drives increasing platelet aggregation at the site
platelet factor 4
binds to heparin and inactivates it
serotonin
induces vasoconstrition
thromboxane
released by platelets, further platelet aggregation
how does fibrinogen link platets
GpIIb-IIIa
thrombin
binds to platelet surface
what does platelet activation cause
expression of phospholipid complexes on surface of platelets which act as surfaces to bind coagulation factors and calcium - promote coagulation
