Hemodynamics Flashcards
What does exudate contain that transudate does not
Inflammatory cells
Examples of Localized Increased hydrostatic pressure
Venous stasis
Ascites
Examples of Generalized Increased hydrostatic pressure
Cardiac Failure
Renal Failure
What infiltrate is indicative of liquefactive necrosis
Neutrophils
What are the reasons a transudate can form?
Increased Hydrostatic Pressure Loss of Plasma Colloid Increased Vascular Permeability Impaired Lymphatic Drainage Salt and Water Retention
What is the difference b/w hyperemia and congestion?
Hyperemia = Active process due to increased blood inflow
Congestion = Passive process due to impaired venous outflow
Why would Renal Failure patients have non-gravity dependent edema?
Because their edema is due to a loss of colloid pressure, not hydrostatic pressure
Why is ventricular hypertrophy such a threat to induce heart failure?
Because there is no angiogenesis in the heart tissue. The heart muscle gets bigger without a corresponding increase in bloodflow to support it
Clinical symptom of left ventricular failure
Pulmonary Edema
Clinical symptom of right ventricular failure
Pitting edema. Blood accumulates in lower extremities because it cannot return to heart effectively
Clinical symptom of congested liver
Ascites
what happens to the architecture of the lungs after long-term heart failure?
Septa become very thickened.
Macrophages ingest RBC and form HFC’s to retain iron
What is amyloidosis
Amyloid is a misfolded protein that can accumulate in blood vessels
What can pericardial hemorrhage lead to
Tamponade
What is the state of normal hemostasis?
Conditions that allow for the fluidity of the blood to be maintained as well as allow for the formation of a solid plug to close a vascular defect
What are the three factors that determine hemostasis and thrombosis
Vascular endothelium
Platelets
Coag System
Endothelial cell anti-thrombotic properties
Antiplatelet effects
Anticoag properties
Fibrinolytic properties
Endothelial cell
PRO-thrombotic properties
Adhesion of platelets
Make vWF
Make TF
What is the first thing that happens after a vascular injury?
Transient arteriorlar vasoconstriction (reflex pathway)
What is exposed after a vascular injury that facilitates platelet adherence and activation?
Highly pro-throbotic subendothelial ECM
What is factor 3?
Tissue factor, made by endothelial cells
What factor does factor 3/TF mix with to help start the coag cascade?
Factor 7
What is the main goal of the cascade?
Activate Thrombin
What does activated Thrombin do?
It cleaves fibrinogen to create the insoluble fibrin
It also recruits more platelets to the clot
What happens after the clot has controlled the bleeding?
Fibrinolysis occurs to help smooth out the clot and limit its size so it doesn’t disrupt laminar blood flow
What is the fibrinolysis molecule released by Endo Cells?
t-PA
What does thrombomodulin do?
Blocks additional coagulation cascade activity
What can “trick” endothelial cells into forming clots without injury to the vessels?
Microbes
Inflammatory mediators
hemodynamic forces
What does heparin do?
It binds to thrombin and causes a modification so that it cleaves Protein C instead of Fibrinogen
Protein C is an anticoagulant
What factors does Protein C cleave?
5a and 8a
What does t-PA stand for?
Tissue type plasminogen activator, which cleaves plasminogen into plasmin
What does plasmin do
Cleaves insoluble fibrin to bust up clots
What makes vWF?
EC’s
What does vWF do?
It binds to both platelets and sub-endothelial ECM
What secretes PAI? (Plasminogen activator inhibitors)
EC’s
What do PAIs do?
Favor thrombosis by limiting plasminogen activity
What makes platelets
Megakaryocytes in bone marrow
What 2 things do platelets need to do to work?
Have a contractile cytoskeleton
Secrete 2 Cytoplasmic granules
What are the 2 Granules
Alpha granules
Dense bodies
What do Alpha granules have inside?
P-selectin (adhesion)
Fibrinogen (fibrin precursor)
Fibronectin
Factors 5 and 8
What do dense bodies have?
ADP/ATP
Ca++
Histamine
Epi
What bleeding disorders are caused by missing or defective vWF
Von Willebrands’
Bernard Soulier
What happens when a Platelet has adhered (via vWF and ECM Collagen)
It changes shape and releases its granules and expresses binding sites for fibrinogen
In normal vessels what two mediators are constantly keeping hemostasis in balance
EC: PGI2 (vasodilator)
Platelet: TxA2 (Thromboxane) Promotes platelet aggregation
What does Aspirin do?
Permanently blocks TxA2. It also blocks PGI2 but the ECs can remake their own Cyclooxygenase to make more PGI2
What works in a similar manner to Aspirin?
NO Nitric Oxide
What factor does heparin inhibit?
10a
What is virchow’s triad
Edothelial Injury
Changes to normal blood flow
Blood Stasis
What are lines of zahn
Show there is still laminar blood flow and the RBC and platelets are forming in layers
What organs will have Red Infarcts instead of Pale?
Those with dual blood supply like the lungs or the GI tract
