Circulation 2 Flashcards
What are the 3 main causes of Thrombosis
- Changes in intimal surface of vessel
- Changes in pattern of blood flow
- Changes in blood consitituents
What can smoking cause? (in terms of platelets)
Platelets are able to aggregate easier and more likely cause thrombosis
What is an Atheroma and what does it cause?
- Disease of the coronary arteries which result in build up of lipid
- Resulting in abnormal blood flow - either slow or turbulent
What does slowed blood flow predispose to?
Fibrin and platelet clumping
What happens when intimal surface is ruptured?
- Platelets and fibrin exposed to abnormal substance (lipid and collagen)
- Causes turbulent flow (or slowing) and substances are deposited into artery
- Thrombus blocks lumen of coronary artery
- Clot forms in stagnant blood behind thrombus
What are lines of Zahn
Multiple layers of thrombus and clot after initial thrombus layer
What happens when there is a partial obstruction in artery?
- Tissue being supplied recieves less blood flow = Ischaemia
- Which leads to decreased oxygenation of tissues = Hypoxia
What is an infarct?
Localised area of dead tissue
What is necrosis?
Process of tissue dying
What is an infarct?
Necrosis as a result of Ischaemia
What is an Embolism?
A mass of material moving in the vascular system and able to become lodged in a vessel and block its lumen
What is a thromboembolism?
When a thrombi/clots embolise
How does a pulmonary embolism occur?
- Reduced flow in veins lead to thrombosis and clot formation
- Part of thrombosis breaks off and travels up vein
- Embolus passes into inferior vena cava, then right heart, then pulmonary trunk and lodges in pulmonary artery
- Causes pulmonary Infarct
What kind of embolism can a fractured leg cause or a knife wound in the neck?
- Marrow embolism
2. Air embolism
