Semilunar valves prevent backflow in the heart; Ligamentum arteriosum connect aorta and pulmonary trunk; Blood vessel diameter affects blood pressure regulation.
Semilunar valves are positioned at the base of the aorta and pulmonary arteries; they prevent backflow of blood into the heart. Ligamentum arteriosum connects the pulmonary trunk to the aorta. Blood vessel diameter impacts blood pressure regulation through vasoconstriction and vasodilation.
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