Regarding the pathophysiology of primary hypertension, damage to blood vessel walls that results from the release of inflammatory substances and the process of arteriolar remodeling results in:
Select one: a. insulin resistance b. an increased cardiac output c. a defect in renal sodium excretion d. increased peripheral resistance
The correct answer and explanation is:
The correct answer is d. increased peripheral resistance.
Explanation:
Primary hypertension, also known as essential hypertension, is a complex condition with various contributing factors. The pathophysiology of primary hypertension involves multiple mechanisms that increase blood pressure over time. One of the most important processes in the development of hypertension is the damage to blood vessel walls, particularly the small arterioles. This damage is driven by the release of inflammatory substances, such as cytokines, and by the process of arteriolar remodeling.
Arteriolar remodeling refers to changes in the structure of the blood vessels, which can result in vascular hypertrophy (thickening of the vessel walls) and reduced lumen diameter. As these small vessels constrict and become less flexible, they increase peripheral vascular resistance, which is the resistance to blood flow in the peripheral circulatory system.
This increased resistance forces the heart to pump more vigorously to overcome the higher pressure in the arteries, leading to an increase in systemic blood pressure. Over time, these changes in the blood vessels contribute significantly to the sustained high blood pressure seen in individuals with primary hypertension.
In addition to arteriolar remodeling, the inflammatory substances released during this process can affect endothelial function, impair vasodilation (the ability of blood vessels to expand), and increase the production of substances like endothelin, which constrict blood vessels.
As a result, peripheral resistance plays a central role in maintaining elevated blood pressure in primary hypertension. The increased resistance to blood flow means that more force is required from the heart to circulate blood, contributing to the overall increase in blood pressure. This phenomenon is a key characteristic of primary hypertension and distinguishes it from other forms of hypertension that may have secondary causes, such as kidney disease or endocrine disorders.