Edema Flashcards
what is Edema?
Increased fluid within interstitial tissues
what are the 5 pathophysiological categories (causes) of Edema?
1) ↑ hydrostatic pressure, ↓ venous return
2) Reduced plasma osmotic pressure
3) Lymphatic obstruction
4) Sodium and water retention
5) Inflammation
what are the 2 forms of “generalized” edema?
anasarca (severe systemic edema)
hydrops (fetal edema)
what are the characteristics of transudate? exudate?
Transudate- low protein content, few cells
Exudate- High protein content, may contain white/red blood cells
what is effusion? give examples of forms of effusion
Effusion- collection of fluid in body cavity or space
Examples:
- Pleural
- Pericardial
- Peritoneal (ascites)
- joint space (synovial)
____________ is an increased tissue blood volume secondary to neurogenic mechanisms or inflammation (active)
Hyperemia
____________ is an increased tissue blood volume secondary to impaired venous return (passive)
congestion
congestion is caused by a blockage of blood ______
outflow
what is the difference between a Hematoma, Ecchymosis, Purpura and Petechia?
Hematoma, large mass of blood
Ecchymosis, >1 cm (bruise)
Purpura, 0.3-0.9 cm
Petechia, 1-2 MILLImeters (pinpoint)
what is a Hemmorage?
Loss of blood secondary to vessel injury or physical disruption
give examples of hemmorages into body spaces:
hemothorax, hemopericardium, hemarthrosis, hemoperitoneum
when does shock due to hemorrhaging occur?
during acute hemorrhage when > 20% of blood is lost
chronic hemorrhaging is called _____
anemia
what are the 3 major components of hemostasis?
1) endothelium
2) Platelets
3) Coagulation cascade
Exposure of basement membrane collagen will automatically binds free floating __________
vWF (von-willebrams factor)
what are the 3 phases to form a platelet plug?
Adhesion, secretion, aggregation
vWF will bind to what location on the surface of platelets to start adhesion?
glycoprotein 1B
what occurs during the secretion phase of platelet hemostasis?
1) platelets release ADP and Ca2+
2) expression of surface phospholipid (PL) complex
what is the Aggregation phase of platelets mediated by?
mediated by ADP, TXA2, and thrombin
what occurs when platelet fibrinogen binds to GP IIb-IIIa ?
the platelet plug becomes cemented by fibrin.
the coagulation cascade is a series of _________ conversions
enzymatic
during the coagulation cascade, where does the calcium-active enzyme-cofactor-substrate unit function?
(in other words, where are the enzyme reactions taking place)
at the phospholipid complex on platelet membranes
what triggers the extrinsic coagulation cascade?
activated by tissue factor (thromboplastin)
what activates the intrinsic coagulation cascade?
Factor XII
______ and ______ are the final end-products of the coagulation cascade
fibrin and thrombin
Extrinsic and intrinsic both come together through factors ____ and _____ during coagulation
factors 9 and 10
__________ plays a role throughout the entire clotting cascade
thrombin
how does vasoconstriction play a role in regulating coagulation?
contraction of vessel walls creates a smaller size of exposure
what are the 4 stages of secondary hemostasis?
1) release of tissue factor
2) Phospholipid complex expression
3) Thrombin activation
4) Fibrin polymerization
what molecules are secreted to shut down the coagulation of platelets?
(during antithrombic counter-regulation)
PGI2
NO
ADPase
what molecules work together to stop the progression of fibrin clots?
Antithrombin III
Protein S (cofactor)
Protein C
thrombomodulin
what 2 molecules work to break down fibrin?
tissue plasminogen activator (tPA)
plasmin
protein C requires protein S in order to inactivate factors __________ and _________
factors 5a and 7a
how does thrombomodulin block the coagulation cascade?
It reduces blood coagulation by converting thrombin to an anticoagulant enzyme
- it is produced on the surface of endothelial cells
