Coronary artery disease Flashcards
to beat mo the po
What are the layers of an artery
Tunica adventitia Tunica media (vasvcular smooth muscle cells) Tunica intima (mono layer of specalised cells)
What do vascular endothelial cells release
baso reactive shit - they affect the blood vessel if it is in a relaxed or controlled state
What is important in regulating how endothelial cells release stuff
Shear stress
What does the endothelial cell layer provide
it stops platelets sticking to wall via having (Prostcytlin)
What is the contraction of smooth muscle cells controlled by in vessel walls
potassium
can smooth muscle cells proliferate and relocate
yes
What happens to a high level of LDL
it becomes oxidised and causes vascular damage
What is cholesterol an essential part of
cell membranes
Where can an atherosclerotic plaque likely form
where turbulent blood flow occurs eg bifurcations due to the wall thickness and this may then promote lipid retention and lesion formation
How does an atherosclerosis form
- Injury to the endothelium
- Endothelial dysfunction
- Adhesion and migration of immune cells into the vessel wall
- Foam cell formation leading to fatty streak
- Progression to intermediate, fibrofatty lesion
- Formation of fibrous plaque
what can cause damage to endothelial cells
smoking
How do fatty streaks form and at what age
Earliest lesion of atherosclerosis
• Appear at a very early age (<10 years)
• Consist of aggregations of lipid –laden macrophages and T lymphocytes within the intimal layer of the vessel wall
What is formed after a fatty streak
intermediate lesion
What happens in an intermediate lesion
Lipid laden macrophages (foam cells)
• Vascular smooth muscle cells
• Isolated pools of extracellular lipid
What happens after an intermediate lesion
Fibrous plaque
What is a fibrous plaque
- Advanced lesion
- Impedes blood flow
- Prone to rupture
- Covered by dense fibrous cap that overlies lipid core and necrotic debris
- May be calcified
- Contains:Smooth muscle cells, macrophages & T Lymphocytes
What happens at the fibrous plaque when things go wrong
fibrous cap ruptures and then platelets can stick and then blood clot forms
What does ptca stand for
PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY
What is restenosis
renarrowing of the arteries after angioplasty (now stents are insertsed to hold the vessel open)
What do drug eluting stents do
they prevent restenosis and require antithrombotic agents to be taken
