What are the different ways, physiological and pharmacological, in which blood vessel diameter can be modified? Detection of changes in blood pressure (leading to resultant changes in blood vessel diameter): Baroreceptors at the carotid sinus (the bifurcation of internal and external carotid arteries in the neck) and the aortic arch detect changes in blood pressure. These non-encapsulated nerve endings, located in the adventitial layer of arteries, are technically mechanoreceptors; they respond to arterial distension occurring …showed first 75 words of 1291 total…

…showed last 75 words of 1291 total…such as nifedipine and amlodipine bind to the L-type Ca2+channels and block the entry of Ca2+into the cell. Since, as described earlier, cytosolic [Ca2+] determines the force and extent of contraction in the vascular smooth muscle, these agents increase the sympathetic tone of the arteriole walls, i.e. decrease the diameter of blood vessel walls. Nitroprusside leads to release of nitrous oxide by the endothelial cells of the capillaries. This results in vasodilation.