Vascular Heart Disease Flashcards
What is the intimal response to vascular injury?
Intimal Thickening
- recruitment of smooth muscle cells
- smooth muscle cell mitosis and ecm matrix
- more thick and harder to provide nourishment to inner layers–>ischemic change
What is arteriosclerosis?
Hardening of the arteries (arterial wall thickening and loss of elasticity)
- Atherosclerosis
- Monckeberg’s medial calcific sclerosis
- Arteriosclerosis-hypertension induced
Atherosclerosis
Elastic Arteries and Muscular Arteries
Response to Injury Hypothesis:
-Atherosclerosis is a chronic inflammatory response of the arterial wall to endothelial injury
-Lesion progression involves interaction of lipoproteins, monocyte-derived macrophages, T lymphocytes and the cellular constituents
What is an atheroma?
Intimal Process!
Fibrous cap: smooth muscle cell, macrophages, foam cells, lymphocytes, collagen, elastin, proteoglycans, neovascularization
Necrotic center: cell debris, cholesterol crystals, foam cells, calcium
What can happen to complicated plaques?
- rupture/ulceration/erosion
- emboli
- hemorrhage
- weakening of media-aneurysm formaiton
- calcification, growth, lumen occlusion
- thrombosis
What are some complications that can arise from atherosclerosis?
- Myocardial ischemia–>angina, infarcts, sudden death
- cerebral ischemia–>stroke, TIA
- Peripheral Vascular Disease–>claudication, gangrene
- Aneurysms–>rupture
What is Monckeberg’s Medial Calcific sclerosis?
Media process!
- Calcific deposits
- Location: Medium sized muscular arteries
- Nonobstructive
Hypertension Induced Arteriosclerosis:
Hyaline arteriosclerosis
Location: Arterioles
Hemodynamic Stress causes leakage of plasma proteins (because endothelial cells are no longer tight) which results in homogenous pink hyaline thickening and lumen narrowing
-kidney and brain–>subtle ischemic changes over time
Hypertension Induced Arteriosclerosis:
Hyperplastic arteriosclerosis
Caused by: severe acute blood pressure elevation
Results in: onion skin concentric thickening get:
- smooth muscle with thickened, reduplicated membranes
- ->progressive luminal narrowing
What is an aneurysm?
localized abnormal dilation of a blood vessel
saccular: one side
fusiform: two sides
false: injury to wall of blood vessel and blood is encased-filling up to look like outpouching
What are 3 ways aneurysms happen?
- poor intrinsic quality of vascular wall connective tissue
- marfans(defect fibrillin), ehlers danlos (defect type 3 collagen)
- bad connective tissue - weakened vascular wall through loss of smooth muscle cells or inappropriate synthesis of extracellular matrix
- ischemia ( atherosclerosis, HTN, Syphilis) –cystic medial degenreation
- loss of smooth muscle - altered balance of collagen degradation and synthesis
- inflammation
- destructive proteolytic enzymes: matrix metalloproteinases
- degradation of collagen
What causes aneurysms?
- atherosclerosis
- HTN
- Congenital defects
- Inflammation: vasculitis, infection
- trauma
What is cystic medial degeneration?
elastin fragmentation–>loss of smooth muscle cells leading to areas resembling cystic spaces
-degradation of elastin
How do abdominal aortic aneurysms happen?
- Destruction of aortic wall connective tissue
- matrix metalloproteinases play a key role
Atherosclerosis
- compress media
- compromises nutrient and waste diffusion from vascular lumen into arterial wall
- media undergoes degradation and necrosiss
- arterial wall weakness and thinning
Where do AAA happen?
infrarenal
-above aortic bifurcation
