Blood Vessels and Cardiovascular System Flashcards
describe blood vessel composition
- vessels composed of smooth muscle cells and ECM
- inner lumen: endothelial cells
- proportion varies throughout vasculature
describe arterial walls and the layers
- thicker layers to accomodate pulsatile flow and BP
- tunica intima, tunica media, adventitia
describe veins and the layers
thin walled due to reduced pressure
- tunica intima, media, adventitia
describe capillaries and the layers
- smallest vessel for exchange of material between blood and tissue
- basement membrane, tunica intima
what is the blood flow of heart
IVC -> RA -> RV -> pulmonary artery -> lungs -> pulmonary vein -> LA -> LV -> aorta
describe hypertensive vascular disease
- often asymptomatic for years
- over 25% of individuals in general population are hypertensive
what qualifies as stage 1 hypertension
greater than or equal to 130/80 mmHg
what qualifies as stage 2 hypertension
greater than or equal to 140/90mmHg
what is primary hypertension
- idiopathic
- 95% of cases
- favorable prognosis unless complication such as MI or stroke
what is secondary hypertension
- related to an underlying condition
- prognosis dependent on tx of underlying disease
what is the most common cause of secondary HTN
renal disease
what are the other causes of secondary HTN
- renal
- endocrine
- cardiovascular
- neurologic
what is the mechanism of essential HTN
- reduced renal/sodium excretion results fluid volume increase
- vasoconstriction or structural changes in vessel wall
- genetic factors
- environmental factors - stress, smoking, obesity, diet
describe atherosclerosis
- chronic arterial disease, consists of cholesterol plaques that lead to hardening and narrowing
- in the US, diseases linked to atherosclerosis are the #1 leading cause of death
- risk factors include nonmodifiable and modifiable factors
what are the nonmodifiable factors of atherosclerosis
- genetic abnormalities
- family history
- increasing age
- male gender
what are the modifable risk factors for atherosclerosis
- hyperlipidemia
- hypertension
- cigarette smoking
- diabetes
- inflammation
what is atherosclerosis characterized by
atheromas that impinge on vascular lumen
- can rupture and cause occlusion
what is atherosclerosis composed of
soft, friable lipid cores (cholesterol) , necrotic debris and a fibrous cap
what do atherosclerotic plaques do
- obstruct vascular lumen leading to stenosis
- prone to rupture -> thrombosis -> occlusion
what is in the fibrous cap
smooth muscle cells
- macrophages
- foam cells
- lymphocytes
- collagen
- elastin
- proteoglycans
- neovascularization
what is in the necrotic center
- cell debris
- cholesterol crystals
- foam cells
- calcium
what is the pathogenesis of atherosclerosis
- chronic inflammatory response of the arterial wall to endothelial injury
- endothelial injury -> accumulation of lipoproteins -> platelet adhesion -> macrophage migration -> lipid accumulation within macrophages -> smooth muscle cell recruitment and proliferation
what type of arteries are most commonly involved in athersclerosis
- large elastic arteries: aorta, carotid, iliac artery
- medium sized arteries: coronary, renal, popliteal
ischemia to what areas are most common in atherosclerosis
- heart
- brain
- kidney
- lower extremities
what are major clinical consequences of atherosclerosis
- myocardial infarction
- stroke
- aortic aneurysm
- peripheral vascular disease- gangrene of extremities