2 HEMODYNAMIC DISORDERS Flashcards
What is thrombosis?
Platelet activation and aggregation WITHOUT vascular damage or blood loss
What does a thrombus refer to?
Platelet plug - clotting WITHIN a blood vessel
What is a Hemolyticdynamic disorder?
Anticoagulation system defect -> excess platelet plug = THROMBUS
What is the actual disorder in hemolyticdynamic disorder?
Disorders that arise from interruptions in normal blood flow without vessel wound or break.
What does the hemodynamic system do?
1 Cause of death in US!!
Functions to slow blood down allowing for the correct amount of blood clotting preventing too much coagulation.
What is a thrombosis?
(Thrombus formation) - platelet activation (Von Willebrand factor is working) and platelet aggregation occurs WITHOUT threat of vascular damage and blood loss -> Platelet plug form (not talking about blood clot, not a part of blood coagulation)
Blood clot can be formed ______
Inside and/or outside of a vessel
Thrombus refers to _____
Blood that has clotted within a blood vessel (blood plug) it always originates from a vascular wall and always maintains a point of contact with the vascular wall through Von Willebrand factor (always stays inside the vessel) –> platelet activation and platelet aggregation
When does a Thrombus only occur?
When there is no problem to lose blood
Thrombus in the arterial system result in _____
The formation of very Dense and Strong, firm and small and fast moving platelet accumulation
Thrombus in the venous system result in ______
Very slow. They are Looser, weaker and larger
What do the Lines of Zahn represent?
A special type of thrombi characterized by visible and microscopic laminations produced by alternating layers
What is a pale layer of Lines of Zahn?
Composed of platelets mixed with fibrin
What is the dark layer of Lines of Zahn?
It is composed of RBC’s
What does the presence of Lines of Zahn represent?
Implies thrombosis in area where blood flow is fast
Where are 2 main areas where thrombi with Lines of Zahn be found?
Heart and Aorta (usually the arch region)
What is an example of Lines of Zahn?
Mitral Stenosis: narrowing of the left atrioventricular opening –> blood flow is slower –> accumulation of blood in L ventricles –> thrombi are formed with lines of Zahn
What is the process of ENDOTHELIAL DAMAGE?
Stretching of endothelial cells from the inner surface of blood vessel –> collagen fibers are overexposed –> first factor for developing thrombus –> thrombus formation
What are the factors predisposing to thrombosis?
Endothelial damage and flow abnormalities
Endothelial damage causes _____
Hemodynamic stress aka Normal wear and tear
What is Hemodynamic stress aka normal wear and tear associated with?
Hypertension, both arterial and venous
What is Hypertension?
Increased resistance and friction between vascular wall and fluid. It is a serious factor that promotes endothelial damage
What are the 2 types of Arterial stress that is associated with Hypertension?
Arterial and Venous
What is hemodynamic stress?
Normal wear and tear resulting in arteriosclerosis, accelerated and strengthen by hypertension
What is atherosclerosis?
Specific changes, such as formation of plaque, in arterial walls. Leads to endothelial damage in the arteries
What does atherosclerosis lead to?
- Platelet aggregation -> Atherosclerotic plugs
- Damaged of endothelial cells
What is associated with Venous Hypertension?
Latrogenic Thrombosis
What is iatrogenic thrombosis caused by?
Medical Care, results in endothelial damage
What is an example of Latrogenic Thrombosis?
Injections into veins damages the endothelia resulting in obliteration of veins and may lead to thrombus formation (rare).
When does latrogenic thrombosis occur?
It is seen only after surgery 95% of thrombus occurs in the deep veins due to slow blood flow
What are Flow Abnormalities?
Reduction in the rate of blood flow or its complete stoppage aka stasis
What do Flow Abnormalities cause?
A decreased rate of flow causes a disruption of axial blood flow & platelets flow closer to the vascular wall
What is the flow chart for Flow Abnormalities?
Disruption of axial blood flow -> more exposure to collagen fibers -> increased platelet activation -> may lead to thrombus formation
What are the causes for decreased flow rate in the Arterial System?
Cardiac Damage and Increased Blood Viscosity aka Hyperviscosity
What 4 things are associated with Cardiac Damage?
1) Myocardial Infarction (MI)
2) Mitral Stenosis
3) Mural Thrombus
4) Rheumatic Heart Disease
What is Myocardial Infarction?
Dead heart tissue heals/scars over with fibrotic tissue. Decreased cardiac output because CT is not contractile. Decrease strength of heart pump.
What is Mitral Stenosis?
Seen in young people. Narrowing of the valve reduces the speed of the blood -> Thrombus formation in the atrium with lines of Zahn
What is Mural Thrombus?
Thrombi formed in chambers of heart
What is Rheumatic Heart Disease?
Mitral Stenosis slows blood flow in the left atrium & thrombus formation usually kills patient
What does Increased blood viscosity aka Hyperviscosity cause?
Changes blood properties causes blood to flow slower -> predisposition to thrombosis
What 2 diseases are associated with Increased blood viscosity aka Hyperviscosity?
Psoriatic arthritis and Polycythemia
What is Polycythemia?
Overproduction of RBC’s (normal = 3-5 mil/mm3)
What can happen during Polycythemia?
Hematocrit level can be double the normal (>50%) -> Increases friction with the vascular wall -> increased resistance to blood flow -> huge predisposition to thrombosis that can lead to death
Polycythemia is sometimes called
Erythrocytosis
How is Polycythemia different from physiological polycythemia?
It is different from physiological polycythemia as a compensatory mechanism for emphysema or living at high altitude where the amount of RBCs increases but not to the level seen in polycythemia
What are the Flow Abnormalities associated with the Venous System
1) Physical Activity
2) Varicose Veins
3) Turbulence
4) Blood Hypercoagulation
What does Physical Inactivity predispose you to?
Thrombus especially in the lower legs (valve malfunction)
What happens during Valve malfunction?
Valves open due to increase P on one side compared to the other. In physical inactivity deep veins do not move properly and develop thrombus
What does physical inactivity (valve malfunction) cause in the venous system?
Causes muscle contraction required to return blood to the heart since valves are not working correctly -> supplies the additional pressure needed (P is low in veins)
95% of thrombi are formed _____
In the deep veins of the legs
What are Varicose Veins?
Distension of the vein walls from each other. (Tortuosity) causes a gap in between the valves preventing correct closure of the valves (not effective) and flow goes without any restriction
What may varicose veins be due to?
Congenital weakness of the venous tone
When are varicose veins commonly seen?
Pregnancy due to increased pressure and Obese people (compression of organ and veins)
What can help with Varicose Veins?
Wearing tight socks can cause compression
What is Turbulence?
Disruption of laminar flow. Twists and turns in a vessel
What is turubulence due to?
Narrowing of lumen, expanded lumen -> aneurysm, and both will disrupt laminar flow
What can cause Blood Hypercoagulation?
Extensive Burns: increases coagulation, some kidney diseases, heart failure
What disease is associated with Blood Hypercoagulation?
Widespread metastatic tumor growth: malignant tumor
What is the most common cause of Blood Hypercoagulation?
Birth Control Pills
What is the most common cause of Blood Hypercoagulation?
Birth Control Pills: Most common cause and very serious. It causes metabolic disruption specially endocrine imbalance -> no production of hormones that the body needs
What do birth control pills promote?
Obesity, skin problems, atherosclerosis, cervix cancer, and infertility
What do corticosteroids cause?
Blood Hypercoagulation
Also promote thrombosis
