Final answer:
Chronic hypertension causes thickening and narrowing of the blood vessels, a condition known as arteriosclerosis. This process increases resistance to blood flow and can also decrease the elasticity of the blood vessels over time.
Step-by-step explanation:
Chronic hypertension, which is the long-term elevation of blood pressure, causes several changes in the structure and function of blood vessels. The correct answer to the changes caused by chronic hypertension in the blood vessels is c) Thickening and narrowing of the blood vessels. This is also known as arteriosclerosis, where the vessel walls become thicker and the pathway for blood flow narrows, increasing the overall resistance to blood flow. This change is due to the response of the vascular smooth muscle and connective tissue to the increased stress of high blood pressure. Over time, chronic hypertension may also lead to decreased elasticity of the blood vessels, which can further compound the issues caused by narrowing vessels.
Regarding the other options, chronic hypertension typically does not lead to a) Vasodilation; in fact, the process of narrowing and stiffening is antithetical to vasodilation. b) Decreased permeability may occur to some extent, but it is not the primary change associated with chronic hypertension. Finally, chronic hypertension reduces, rather than increases, the elasticity of blood vessels, making d) Increased elasticity incorrect.