Vascular systems smooth muscle damage

Hypertension is defined as a sustained diastolic blood pressure greater than 90 mm Hg accompanied by an elevated systolic blood pressure (>140 mm Hg). Hypertension results from increased peripheral vascular smooth muscle tone, which leads to increased arteriolar resistance and reduced capacitance of the venous system. Elevated blood pressure is an extremely common disorder, affecting approximately 15% of the population of the United States (60 million people). Although many of these individuals have no symptoms, chronic hypertension—either systolic or diastolic—can lead to congestive heart failure, myocardial infarction, renal damage, and cerebrovascular accidents. The incidence of morbidity and mortality significantly decreases when hypertension is diagnosed early and is properly treated. 

The continuous bifurcation of arteries within the cardiovascular system leads to blood flow within the smallest blood vessels of the arterial tree, the capillaries. The function of these important arterioles is to limit blood flow from the larger arteries in order to prevent damage to the fragile capillaries that connect the arterial vascular tree to the venous system. The capillaries also regulate, through a complex interaction with autacoids, hormones and neurotransmitters, the microcirculation by altering arterial smooth muscle wall tone (Pugsley and Tabrizchi 2000). 

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