Atherosclerosis Quiz 1

Blood Vessels and Blood Flow

• Increased wall tension in blood vessels is contributed by an elevated transmural pressure.
• Sustained elevated blood pressure over time leads to hypertrophy of vascular walls.

Blood Flow and Velocity

• There is an inverse relationship between blood flow velocity and cross-sectional area.
• Slow blood velocity in capillaries allows for efficient exchange of substances.

Endothelial Cells and Smooth Muscle Layers

• Nitric oxide is the main biochemical mediator produced by endothelial cells and smooth muscle layers.
• Elevated levels of LDLs in the intima initiate the process of increased endothelial permeability.

Plaque Growth and Atherosclerosis

• The next phase of plaque growth after recruitment of vascular smooth muscle cells is the formation of a fibrous cap.
• A characteristic of atherosclerosis is the accumulation of lipids and inflammatory cells in the arterial wall.
• Rapid expansion of a plaque in atherosclerosis can be caused by hemorrhage or inflammation within the plaque.
• Consequences of a ruptured plaque in atherosclerosis include thrombus formation and vessel occlusion.
• Matrix metalloproteinases (MMP) contribute to the degradation of the extracellular matrix in atherosclerosis.

Arterial Structure and Function

• Endothelial cells form a barrier that contains blood within the lumen of the vessel and controls the passage of solutes and cells from the circulation into the subendothelial space.
• Endothelial cells secrete substances such as nitric oxide to modulate the contraction of smooth muscle cells in the underlying medial layer.
• Healthy arterial endothelial cells play a role in the immune response by modulating inflammation.
• The media layer of normal muscular arteries contains most of the smooth muscle cells (SMCs).
• Medial smooth muscle cells (SMCs) in normal arteries produce collagen and elastin.

Atherosclerosis and Related Conditions

• During atherogenesis, medial smooth muscle cells (SMCs) can proliferate and migrate into the intima.
• Large arteries have much thicker walls compared to veins of similar size due to higher blood pressure.
• Autosomal dominant hypercholesterolemia is a disorder associated with lifelong elevated levels of LDL cholesterol.

Cardiovascular Function

• The exogenous pathway involves the absorption and repackaging of dietary fats in the small intestine.
• Peak blood flow occurs during the diastolic phase of the cardiac cycle.
• A vascular aneurysm in atherosclerosis can be caused by the degradation of the extracellular matrix.

Coronary Artery Tone and Myocardial Oxygen Supply

• Metabolic factors such as ATP and adenosine control coronary artery tone.
• Nitric oxide is an endothelial factor that regulates coronary artery tone.
• Beta-adrenergic receptors in coronary vessels promote vasodilation.
• An increase in heart rate decreases myocardial oxygen supply.
• The hemodynamic significance of a coronary artery stenosis is determined by the size of the stenosis and the myocardial oxygen demand.

Cardiac Perfusion and Angina

• Nuclear imaging is used to assess cardiac perfusion and diagnose myocardial ischemia.
• Females with angina are more likely to report symptoms such as fatigue and dyspnea.
• Pathological analysis reveals that coronary artery narrowing is often not the only factor contributing to myocardial ischemia in females.