Anatomy of Blood Vessels
What are the 3 layers that make up blood vessels, from smallest to largest?
BONUS! What is the "vaso vasorum" and on what layer is it located?
Tunica intima, tunica media, tunica externa (adventitia)
"blood vessels of blood vessels" on tunica externa
What term describes leukocyte adhesion when leukocytes "roll" in order to leave the cell?
Diapedesis
What are the 2 broad categories of vascular diseases?
Stenosis (narrowing)
Aneurysm (weakening of vessel walls)
What is ASCVD and what are the 2 main concerns regarding the disease?
Atherosclerotic Cardiovascular Disease
-heart attack and stroke
What is vasculitis?
refers to inflammation of blood vessels, leading to vessel wall damage, thrombosis, and ischemia of affected tissues
Tunica media
What is the most common result of nitric oxide production in intact endothelium?
vasodilation
Vascular injury leads to endothelial cell ___________, stimulating smooth muscle growth and ____________ ___________ synthesis, causing intimal thickening.
Vascular injury leads to endothelial cell _dysfunction_, stimulating smooth muscle growth and _extracellular matrix (ECM)_ synthesis, causing intimal thickening.
What are modifiable and non-modifiable risk factors of Atherosclerosis?
Non-Modifiable:family history, increasing age, genetic abnormalities
What are varicose veins and the common causes?
dilated superficial veins (usually in lower extremities) caused by chronic elevated pressure
causes: pregnancy, hereditary venous defects, obesity
What 3 types of cells/tissue are blood vessels made of?
endothelial cells, smooth muscle cells, and connective tissue
What is neointima?
initial thickening of injured vascular wall due to smooth muscle cell growth and ECM production
2 most important causes of endothelial dysfunction:
1) hemodynamic disturbances
2) hyperlipidemia (plaque)
Describe the 3 main differences between Stable plaques and Vulnerable plaques.
Stable: smaller areas of foam cells/lipids, thick fibrous caps, few inflammatory cells
Vulnerable: larger areas of foam cells/lipids, thin fibrous caps, lots of inflammatory cells
What is the pathophysiology of hypertension?
hypertension promotes endothelial dysfunction, smooth muscle cell growth, and intimal thickening--> contributing to arterial wall rigidity and narrowing --> raising risk of CV events
What are the 3 main vascular structures and a brief description of structure and function?
Arteries: large/medium size (mainly tunica media) --> bring blood to body tissues
Veins: small, medium, and large --> bring blood back to the heart
Capillaries: only 1 endothelial cell lining (no media) --> site of gas exchange
Provide the type of junction or description of the following endothelial cell properties:
Continuous Discontinuous Fenestrated
Continuous: tight junctions
Discontinuous:gap junctions
Fenestrated: contain holes/pores
What is the role of hyperlipidemia in atherogenesis?
Hyperlipidemia causes increased ROS production, which leads to oxidized LDL formation. These LDLs are then taken up by macrophages leading to foam cell formation --> atherogenesis
What are the 4 subcategories of ASCVD?
1) Coronary heart disease
2) Cerebrovascular disease (stroke)
3) Peripheral artery disease (critical limb ischemia)
4) Aortic atherosclerosis (AAA/TAA)
What are esophageal varices?
enlarged veins in the esophagus caused by portal hypertension --> typically due to liver cirrhosis
What is the function of Vascular Smooth Muscle cells and in which direction in the vessel walls do they migrate?
-release cytokines and growth factors; migrate & proliferate; synthesize and remodel ECM; cause vasoconstriction/dilation
-move from media to intima
What are the 2 endothelial cell states and which one is present under normal pressure versus injury?
2) Activated endothelial state (injured)
What is the renin-angiotensin-aldosterone system (RAAS)?
Renin(released by kidneys) activates conversion of Angiotensinogen to Angiotensin I, which is converted to Angiotensin II in the lungs. Angiotensin II causes vasoconstriction and stimulates aldosterone release to retain NA2+ and water.
Explain apoB and its clinical significance.
ApoB is a biomarker in blood that can help measure risk of ASCVD
What are the 2 common pathogenic mechanisms of vasculitis?
1) immune-mediated inflammation
2) direct invasion by infectious pathogens