Hemodynamic Disorders, Thromboembolic Disease and Shock Flashcards
Where does fluid accumulate in:
Edema
Effusion
Edema: interstitial space.
Effusion: potential space (body cavities), i.e. pleural space, peritoneal space (ascites), pericardium, joint space, etc.
What pressure wants to push fluid out of capillary?
What pressure wants to pull fluid into the capillary?
Hydrostatic pressure
Colloid osmotic pressure
4 mechanisms of edema
- Increased intravascular hydrostatic pressure (Na+ and water retention, congestion).
- Reduced plasma oncotic pressure.
- Increased vascular permeability.
- Lymphatic obstruction
Hyperemia
Congestion
Too much blood arriving (physiologic, arterial).
Not enough blood leaving (pathologic).
What sorts of edema does heart failure cause? (3)
Soft tissue, pulmonary edema, pulmonary effusion.
Mechanisms of heart failure leading to edema/effusion (2)
Retention of Na+ and water due to increased volume and decreased oncotic pressure.
Decreased pump activity –> back-up of pulmonary venous circulation (congestion).
2 ways renal disease can result in edema
- Retained Na+ and water –> increased intravascular hydrostatic pressure.
- Nephrotic syndrome (excess protein loss in urine) –> decreased plasma oncotic pressure.
Kwashiorkor is a deficiency in:
Deficiency in protein –> reduced plasma oncotic pressure
3 ways we can have low protein (low plasma oncotic pressure)
- Not enough ingested: malnutrition.
- Not enough made: liver failure.
- Too much lost: kidney disease w/ nephrotic syndrome.
What kind of edema does lymphedema typically cause:
What would be in the differential?
Localized edema.
Infection, inflammation, trauma, tumors, surgery, malformations, etc.
Types of fluid leaving the intravascular compartment are transudate or eudate. What causes them? What is their makeup?
Transudate: increased hydrostatic pressure (venous obstruction, CHF, etc). Low protein, few cells.
Exudate: increased interendothelial spaces (gaps in endothelium). High protein content and may contain RBCs and/or WBCs. Found in places with increased inflammation.
3 causes of chronic congestion
Edema
Hemosiderosis
Tissue damage
What are “heart-failure cells”?
Hemosiderin-laden macrophages in areas of chronic congestion.
Main cause of hepatic congestion?
What is the pathology?
Advanced HF.
Central vein obstruction or flow reduction.
What is “nutmeg liver”?
Liver is nutmeg color (alternating brown and white) indicative of chronic hepatic congestion.
1st step in hemostasis
Primary hemostasis (1st step)
Primary hemostasis (2nd step)
Primary hemostasis (3rd step)
Site of injury causes a reflex constriction by releasing Endothelin.
Platelets adhere to the sub-endothelial surface.
Platelet activation.
Platelet aggregation.
What proteins are involved in the adhesion of platelets to the sub-endothelial surface?
GpIb on platelet bins to von Willebrand factor (vWF) on the surface.
Fibrinogen binds to what on the platelet?
Binds to GpIIb-IIIa on platelets and allows aggregation.
Disease caused by deficiency in GpIIb-IIIa
Glanzmann thrombasthenia
Disease caused by deficiency in GpIb
Bernard-Soulier syndrome
Disease caused by deficiency in vWF
von Willebrand disease
Weibel Palade bodies
Storage granules in endothelial cells that contain vWF (also integrins).
What is the structure of Weibel Palade bodies?
Coiled, looks like a spring.
What us ADAMTS13?
Can limit thrombus formation by cleaving vWF.
What is clustered in pairs at platelet attachment sites?
Alpha-Beta integrins
What disease is known to have “giant platelets”?
Again, what is its pathology?
Bernard-Soulier syndrome
Lack of GpIb
What 3 things allow for platelet activation (post adhesion)?
Conformational change (increase in SA). Its negatively charged surface. GpIIb-IIIa change - fibrinogen links.
What triggers secretion of molecules once the platelet is activated?
What does it cause the secretion of and what do they do? (2)
Thrombin initiates it.
ADP (more activation) and Thromboxane A2 (more aggregation).
FYI that thrombin also has antithrombotic effects.
What does aspirin inhibit?
Thromboxane A and COX
End result of primary hemostasis:
Formation of the platelet plug
Clinical sign of problems with primary hemostasis: (1)
Laboratory sign of problems with primary hemostasis: (3)
Mucocutaneous bleeding (gums, nosebleeds).
Bleeding time (not really used anymore), platelet function studies, PFA-100.
Modern techniques for determining platelet malfunction (2)
Flow cytometry
PFA-100 (adhesion, aggregation)
Thrombocytopenia
Mechanism:
Platelet count:
Platelet adhesion:
Platelet aggregation (Y/N):
Mechanism: loss or impaired production of platelets. Platelet count: very low. Platelet adhesion (Y/N): yes Platelet aggregation (Y/N): yes
von Willebrand disease
Mechanism:
Platelet count:
Platelet adhesion:
Platelet aggregation (Y/N):
Mechanism: inherited lack of vWF. Platelet count: normal. Platelet adhesion (Y/N): no. Platelet aggregation (Y/N): yes.
Bernard-Soulier disease
Mechanism: Platelet count: Platelet adhesion (Y/N): Platelet aggregation (Y/N):
Mechanism: abnormal GpIb. Platelet count: low to normal. Platelet adhesion (Y/N): no. Platelet aggregation (Y/N): yes.
Glanzmann’s thrombasthenia
Mechanism: Platelet count: Platelet adhesion (Y/N): Platelet aggregation (Y/N):
Mechanism: abnormal GpIIb-IIa. Platelet count: normal. Platelet adhesion (Y/N): yes. Platelet aggregation (Y/N): no.
Adhesion disorders (2)
B-S syndrome
vWF
Aggregation disorder (1)
Glanzmann thrombasthenia
What word should I associate with fibrinogen?
Stabilization during primary hemostasis
Secondary hemostasis is AKA:
The coagulation cascade
Diagram the intrinsic/extrinsic pathways (slide 65)
Draw it
Aliases for:
I
II
VIII
I - fibrinogen
II - prothrombin
VIII - antihemophilic A factor (AHF)
Vitamin K-dependent factors in coagulation cascade (6)
II, VII, IX, X, protein C, protein S. This means they use vit K to bind Ca++.