Circulatory disorders Flashcards
(41 cards)
What are the specific problems of plaque formation?
- Myocarical and cerebral infarcts
- Aortic aneurysms
- Peripheral vascular disease
What is pulmonary embolism?
From venous emboli that pass through the right side of the heart into the pulmonary artery
What 3 alteration to blood constituents cause a thrombus?
1) Increase in cells/platelets and plasma proteins (solid)
2) Decrease in fluid (eg. after severe burns)
3) Blood becomes hypercoagulable (more likely to clot)
What makes up a thrombus?
- Endothelial cells
- Platelets (fragments of cells)
- Coagulation cascade, leading to the production of fimbrin
How does damage to endothelial lining cause a thrombus?
- Damage exposes highly thrombogenic sub epithelial tissue (due to physical, chemical or inflammatory disturbances)
- Balance between release of thrombogenic and anti-thrombogenic stimuli is shifted
What is CHD also known as?
Ischaemic heart disease
In a consecutive clot, what can stabilize the thrombus?
- The blood incoming from the end of a tributary
- Platelets and fibrin
- Can reattach the clot to the vessel wall, permitting further propagation
What are the disadvantages of drug-eluting stents?
- Antiproliferative drugs which are released from the stent prevent the proliferation of endothelial cells
- Not smooth surface
- Platelet aggrucation
- Thrombus formation
(Endothelial cells needed to grow over stent to produce smooth surface for blood flow)
How does turbulence cause a thrombus and where does it occur?
- Occurs around the branches of arteries etc, where different blood flows are hitting each other
- Alteration to the normal, lamellar flow pattern
- Can damage the endothelium
What is a thrombus?
- A solid mass of BLOOD formed within the cardiovascular system
- A ‘clot’
What is restenosis?
The recurrence of abnormal narrowing of an artery or valve after corrective surgery (stenting)
- Smooth muscle cells grow over the stent
What is ATHEROsclerosis?
- Fatty deposits (lipid and cellular debry)
- Disease of the tunica INTIMA
Damage to the endothelial lining which may lead to:
- Narrowing of the vessels
- Obstruction
- THROMBOSIS
What is ‘thrombosis’ and how is it different to a ‘thrombus’?
- Thrombosis is the presence of a clot within a blood vessel
- The clot itself is called the thrombus
What is ARTERIOsclerosis?
Disease of the tunica MEDIA which may lead to:
- Increased wall thickness
- Decreased wall elasticity
- Leads to hypertension (smaller lumen)
What 3 things do the consequences of vascular occlusion depend upon?
- Type of tissue involved (artery or vein)
- How quickly the occlusion occurs (sudden or gradual)
- The availability of collateral circulation (alternative circulation)
What is percutaneous coronary inverventions?
A combination of:
- Angioplasty (balloon opening a blocked vessel
- Stenting (wire mesh)
Maintains lumen size
What causes an arterial thrombus?
- Middle age, elderly
- May have underlying circulatory disorders
- Increase risk by diabetes smoking
What are the MODIFIABLE risk factors of CHD?
Strong association
- Smoking
- Diabetes mellitus
- Obesity
- Hypertension
- Hyperlipidaemia
Weak association:
- Lack of excersice
- High alcohol
- Type A personality (more prone to stress)
- Soft water
What attaches a blood clot to the endothelial wall?
Fimbrin and platlets
What is embolisation?
Carrying of fragments of thrombus into the general circulation, when there is no tributary to able a consecutive clot to be reattached to the blood vessel wall
Normally, where does the fastest blood flow?
In the middle of the bulk of blood
What can 4 things can vascular occlusion be a result of?
- Thrombosis (blood clot)
- Embolism (detached blood clot, can move)
- Atherosclerosis (fatty deposits)
- External compression (eg during an accident)
What is angina?
The pain of CHD, caused by narrowing of the arteries
What are the major components of an atheromatous plaque?
1) Fibrous cap
- Smooth muscle cells
- Collagen
- Elastin
(New cell layer)
2) Cellular layer
- Macrophages, T cells
- Smooth muscle cells
3) Necrotic core
- Lipid and cellular debry
- Cholesterol clefts
- Foam cells
4) Calcification
- Deposition of calcium rich material
