Cardiovascular Disease Flashcards
What is atherosclerosis
buildup of plaque in the artieries
What does the fibrous cap do?
protects the plaque build-up
Fatty deposit (aka plaque)
Fats, cholesterol, and other substances build up in the artery wall
Vulnerable plaques
susceptible to rupture due to high lipid content, increased inflammation, and thin fibrous cap
plaque inflammation and increased arterial pressure can trigger______
plaque rupture
When plaque ruptures, exposure to blood flow triggers _____
A thrombus
Thrombus
blood clot consisting of platelets and insoluble fibrin forms at the site of injury
Myocardial infarction (heart attack)
occurs when a clot completely blocks blood flow to an area of the heart
Heart tissues die when ___
oxygen (supplied by blood) is denied to the tissues
Steps to plaque formation
- Arterial wall damage
- Chemokines secretion
- Foam cell formation
- SMC migration
What happens when the arterial wall is damaged?
LDL enters the blood stream and then LDL is oxidized and retained
What happens when LDL is oxidized?
Endothelial cells are activated secreting chemokines and then monocytes adhere to receptors ICAM and VCAM
Endothelial cell activation leads to :
- Adhesion is molecularly activated
- Secrete chemokines
How are foam cells formed?
monocytes differentiate into macrophages which are then filled with LDL
What is a foam cell?
macrophage filled w/ LDL
What causes SMC’s to proliferate?
Foam cells secrete growth factors that tells the SMCs to multiply
What causes the SMC’s to migrate?
OxLDL binds to the proliferated cells and this causes the release
What do the SMC’s do when they are released?
they begin extracellular matrix formation which is comprised of proteins such as collagen and elastin.
How should the fibrous cap form?
Slowly
What happens if the fibrous cap forms quickly?
the cap doesn’t form well and its likely to rupture
Intima
the area between SMC’s and EC’s
When subendothelial proteins are exposed, this leads to _____
Thrombosis
What is bad cholesterol
LDL- low density lipid protein
What is good cholesterol
HDL- High density lipid protein
HDL function
moves cholesterol from the body to the liver for clearance (removes cholesterol)
LDL function
moves cholesterol to arteries
Why is HDL more dense than LDL?
More protein per lipid
WHat do statins do?
they inhibit HMG=CoA reductase, which is the rate-limiting step of CHolesterol synthesis
Statins ____ and they increase the ____ in the liver which decreases _____
reduce cholesterol synthesis
LDL receptors
LDL by 25%-50%
Vascular grafts are usually made of _____ and are only useful for ______
polymers
large arteries
Vascular grafts are coated with ____ which _____
heparin
prevents clotting
How are stents implanted
- stent is inserted into the artery
- The stent is expanded via a balloon
- The balloon is removed and the stent remains expanded in the artery
Stents are typically made of
metal coated with a polymer
Biggest problem with stents and grafts is that ____
they tend to form a thrombus
Types of anticoagulant coatings
Hirudin
Heparin
TFPI and Thrombodulin both _____
Inhibit binding process of thrombin
Albumin is ____
protein that prevents things from binding
GAGs are
(glycose amino glycans) found on the surface of EC’s and prevents platelet binding
PC is
a phospholipid found in cell membrane that inhibits platelet binding
PEG can
prevent platelet binding
EC’s release nitric oxide which ____
inhibits platelet binding and SMC proliferaiton
Tissue engineered vascular grafts process
- Cells extracted from patient
- Cells expanded in culture
3a. Cells mixed with polymer scaffold material and shaped in mold
3b. Vells seeded into porous polymer scaffold - COnstruct matured in a bioreactor
Nonthrombogenic engineering methods
- Anticoagulant coatings
- Inhibit platelet adhesion/ activation
- In vitro endothelialization
- In situ endothelialization
