CTB7 Flashcards
What is the primary function of the endothelium?
The endothelium regulates vascular tone, barrier function, and inflammation.
How does the endothelium maintain vascular tone?
It releases vasodilators (e.g., nitric oxide) and vasoconstrictors (e.g., endothelin-1).
What is the structure of the vascular intima?
A single-cell endothelial layer forming a non-adhesive, selective barrier.
How do endothelial cells reduce mechanical stress in large vessels?
They elongate and align with blood flow direction to minimise surface forces.
What is the role of nitric oxide in vascular function?
NO is a potent vasodilator that relaxes smooth muscle and inhibits platelet aggregation.
How is NO synthesised in endothelial cells?
NO is produced by endothelial nitric oxide synthase (eNOS) from L-arginine.
What is endothelial dysfunction?
A state where the endothelium loses its ability to regulate vascular tone and barrier integrity.
What is angiogenesis?
The formation of new blood vessels from pre-existing vasculature.
What stimulates angiogenesis?
Growth factors like VEGF (vascular endothelial growth factor) and hypoxia.
How does the media layer of blood vessels differ between arteries and veins?
Arteries have a thicker, more muscular media to withstand higher pressures.
What is the primary function of vascular smooth muscle cells?
To regulate vascular tone through contraction (vasoconstriction) and relaxation (vasodilation).
How is vascular tone controlled?
By endothelial signals (e.g., NO) and autonomic nervous system input.
What is the adventitia layer?
The outermost layer of blood vessels containing fibroblasts, collagen, and elastin.
How does the adventitia contribute to vascular function?
It provides structural support and elasticity to accommodate pressure changes.
What is the role of gap junctions in the endothelium?
Gap junctions enable cell-cell communication and coordinated responses.
What are the functions of endothelial-derived prostacyclin?
It promotes vasodilation and inhibits platelet aggregation.
How do endothelial cells regulate thrombosis?
They balance pro-thrombotic (e.g., von Willebrand factor) and anti-thrombotic (e.g., NO, prostacyclin) factors.
What is the role of endothelial cell junctions?
They maintain barrier integrity and regulate permeability.
How do inflammatory responses affect the endothelium?
Inflammation increases permeability and promotes leukocyte adhesion.
What molecules mediate endothelial inflammation?
Cytokines (e.g., IL-1, TNF-alpha) and adhesion molecules (e.g., ICAM-1, VCAM-1).
What happens to the endothelium in atherosclerosis?
Endothelial dysfunction leads to lipid accumulation, inflammation, and plaque formation.
What is the internal elastic lamina?
A layer of elastin separating the intima from the media in arteries.
How does shear stress influence endothelial function?
Shear stress enhances NO production and maintains endothelial health.
What are the effects of oxidative stress on the endothelium?
Oxidative stress reduces NO availability and promotes inflammation and thrombosis.
