Hemodynamic Disorders Flashcards
What does congestion often occur with?
-edema
Compare and contrast hyperemia and congestion.
- hyperemia: local increased blood volume, active process, increase in arteriolar inflow blood due to arteriolar dilation; redder bc blood is oxygenated (in arteries!!)
- congestion: local increased blood volume, passive process due to decreased venous outflow from an organ. Blue-red tissue= cyanosis due to increased deoxygenated blood
Why are venous thrombi not always associated with congestion and edema?
-most tissues have more than 1 pathway of venous drainage
Give examples of hyperemia and congestion.
- hyperemia: inflammation, exercising muscle, blushing, meningitis, hyperemic borders surrounding infarct (dying cells release inflammatory factors)
- congestion: DVT, right heart failure leading to liver congestion, left heart failure leading to pulmonary congestion
acute vs. chronic passive congestion of liver
- acute: redness in sinusoids and congestion near central vein
- chronic: nutmeg liver; centrilobar congestion and periportal fatty change (fatty bc less O2 reaching them so cannot export fat
Define hemorrhage
-extravasation of blood due to vessel rupture
T/F: all emboli are thromboemboli.
- false; an embolus is any intravascular solid, liquid, or gas that is carried from site of origin by blood to distal site
- thromboembolus is a detached thrombus that embolizes
Arterial thrombi: important factors, major causes, morphology
- Important factors: endothelial injury and turbulent flow
- Major causes: atherosclerosis, vasculitis, trauma, hematologic disorders
- Morph: Prominent lines of Zahn; “white” thrombi due to more platelets/fibrin and fewer RBCs
Compare the risks of arterial thrombi that form in small to medium arteries to those that form in the aorta.
-small-to-medium arterial thrombi are often a risk of occlusion and subsequent infarction, while the aorta is too big to be occluded and is a greater risk of its thrombi embolizing and occluding smaller branch arteries
Venous thrombi: important factors, morphology, locations.
- stasis and hypercoagulable states (genetic or acquired) are important factors
- morph: less prominent lines of zahn, “red” thrombi due to relatively more trapped RBCs due to stasis
- common locations: veins in leg, also pelvic veins too
Cardiac chamber thrombi: important factors (with 4 specific examples) and morphology.
- Factors: endocardial injury, stasis
- Exs: 1. enlarged chambers= poor contractility=stasis 2. atrial fibrillation= local stasis due to incorrect rhythm 3. Post MI: endocardial injury and off-beating = stasis and injury 4. Abnormal valves: endocardial injury from infections or non-infectious like injury
- usually red due to stasis and non-occlusive bc chambers are so big
Places venous thrombi “go”.
- pulmonary circulation
2. systemic circulation: paradoxical embolus is a VTE that passes into systemic circulation via heart
What are paradoxical emboli and give 3 mechanisms for their generation.
- VTE that passes into systemic circulation via the heart when they in theory should end up in the pulmonary circulation
- patent foramen ovale, ductus arteriosus, ventricular septal defect
Where do right and left cardiac chamber thrombi end up?
- Rt: pulmonary arterial circulation
- Lt: systemic arterial circulation
Define organization and recanalization. Be sure to mention specific cell types that are involved.
- organization: ingrowth of granulation tissue cells into thrombus for repair (endothelial cells and fibroblasts)
- recanalization: new vascular channels connecting end to end, allowing reestablishment of blood flow through the scar
