CVS 1- HYPERTENSION Flashcards
What are the two principal mechanisms of vascular disease?
Narrowing or complete obstruction of vessel lumen and Weakening of vessel walls
What results from narrowing or obstruction of the vessel lumen?
Acute or progressive blockage
What happens due to the weakening of vessel walls?
Dilation and rupture
What are the main components of the vessel wall?
Endothelial Cells (ECs)
What does the extracellular matrix (ECM) include?
Elastin
What are the three layers of the vessel wall?
Intima
What influences the variation in vessel wall layers?
Tissue requirements and hemodynamic forces
What is blood pressure a function of?
Cardiac output and peripheral vascular resistance
What influences blood pressure?
Multiple genetic and environmental factors
What does cardiac output depend on?
Stroke volume and heart rate
What influences stroke volume?
Sodium concentration and myocardial contractility
What controls heart rate?
Alpha- and beta-adrenergic systems
What factors affect peripheral vascular resistance?
Arterioles’ neural and humoral inputs
What maintains normal vascular tone?
Balance between vasoconstrictors and vasodilators
What is autoregulation in blood pressure?
Increase in blood flow followed by vasoconstriction
What fine-tunes vascular resistance?
Tissue pH and hypoxia
What organs are involved in blood pressure regulation?
Kidneys, adrenals, and myocardium
What system plays a key role in blood pressure regulation?
Renin-angiotensin system
What triggers the release of renin?
Low blood pressure in afferent arterioles, high levels of circulating catecholamines, and low sodium levels in distal convoluted tubules
What are examples of vasodilators?
Prostaglandins, nitric oxide (NO)
What hormone is released by the adrenal glands?
Aldosterone
What peptide is released by the myocardium?
Natriuretic peptide
What is hypertension (HYPERTENSIVE VASCULAR DISEASE)?
Increased blood pressure with sustained diastolic pressure > 90 mm Hg or sustained systolic pressure > 140 mm Hg
What percentage of the general population is hypertensive?
About 25%
What are the pathological effects of hypertension?
Stroke, coronary heart disease, cardiac hypertrophy, heart failure, aortic dissection, multi-infarct dementia, and renal failure
What is hypertension (HYPERTENSIVE VASCULAR DISEASE)?
Increased blood pressure with sustained diastolic pressure > 90 mm Hg or sustained systolic pressure > 140 mm Hg
What percentage of the general population is hypertensive?
About 25%
What are the pathological effects of hypertension?
Stroke, coronary heart disease, cardiac hypertrophy, heart failure, aortic dissection, multi-infarct dementia, and renal failure
What is malignant hypertension?
Rapidly rising blood pressure that if untreated leads to death within 1-2 years
What are the characteristics of severe hypertension?
Systolic pressure > 180 mm Hg, diastolic pressure > 120 mm Hg, renal failure, retinal hemorrhages, and exudates
What is malignant hypertension usually superimposed on?
Preexisting benign hypertension
What genetic factors are linked to hypertension?
Angiotensinogen polymorphisms, angiotensin II receptor variants
What gene defects cause rare severe forms of hypertension?
Gene defects affecting aldosterone metabolism (aldosterone synthase, 11β-hydroxylase, 17α-hydroxylase)
What do mutations affecting sodium resorption cause?
Increased distal tubular resorption of sodium
What are the environmental factors contributing to hypertension?
Stress, obesity, smoking, lack of exercise, heavy salt consumption
What effect does hypertensive vascular morphology have on atherogenesis?
Accelerates atherogenesis
What changes occur in the walls of large and medium-sized arteries due to hypertensive vascular morphology?
Degenerative changes including aortic dissection and cerebrovascular hemorrhage
What are the two forms of small blood vessel disease associated with hypertensive vascular morphology?
1) Hyaline arteriolosclerosis 2) Hyperplastic arteriolosclerosis
What condition is hyaline arteriolosclerosis associated with?
Benign hypertension
What is a key characteristic of hyaline arteriolosclerosis?
Thickening of arteriolar walls
What type of material is found in hyaline arteriolosclerosis?
Homogeneous pink hyaline material
What happens to the underlying structural details in hyaline arteriolosclerosis?
Loss of underlying structural details
What happens to the arteriolar lumen in hyaline arteriolosclerosis?
Narrowed arteriolar lumen
What causes the leakage of plasma proteins in hyaline arteriolosclerosis?
Leakage of plasma proteins across the endothelium
What happens to extracellular matrix (ECM) synthesis in hyaline arteriolosclerosis?
Excessive ECM synthesis
Who is more likely to develop hyaline arteriolosclerosis?
Elderly & Diabetics
What condition is hyperplastic arteriolosclerosis characteristic of?
Severe “malignant” hypertension
What is a key feature of hyperplastic arteriolosclerosis?
Onion skin - concentric and laminated wall thickening
What effect does hyperplastic arteriolosclerosis have on the arteriolar lumen?
Arteriolar luminal narrowing
What do the laminations in hyperplastic arteriolosclerosis indicate?
SMC with thickened basement membrane
What severe condition is associated with malignant hypertension in hyperplastic arteriolosclerosis?
Necrotizing arteriolitis (fibrinoid necrosis)
