Relationship between blood vessel resistance and heart function

¶ … blood vessel resistance and heart function. In the paper, four peer reviewed journals are looked at to highlight any potential relationship between blood vessel resistance and the heart's functioning.

In normal functioning of the heart, there are critical factors that influence blood resistance. These factors include blood vessel's radius, blood viscosity and vessel length (Cinar, Demir, Pac, & Cinar, 1999). Of the three factors, vessel diameter is the most important in determining blood vessel resistance and heart functioning. Vessel changes due to contraction and relaxation of the vascular smooth muscle in the wall of the blood vessel directly influencing blood resistance which then affects heart functioning. In addition, small variations in vessel diameter leads to large changes in resistance which affect heart functioning.

Effect of Blood Vessel Radius on Blood Flow Rate

Increase or decrease in blood vessel radius can either increase or reduce blood flow rate to the heart. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance. Therefore, dilation of arterial blood vessels causes a decrease in blood pressure. The widening of blood vessels which bring changes in their radii thus takes a lot of blood into the heart thus making the heart to work harder. This may lead to heart fatigue due to the pumping of increasing blood volumes by the heart (Huang-Wen, Tzu-Ching, & Chihng-Tsung, 2010). In addition, increased vessel radius affect blood pressure thus, changing the heart valve orifice size increasing blood flow and pressure gradients across heart valves. Besides, the higher the blood volume in the body, the higher the blood flow rate to the heart resulting in high cardiac output.

The narrowing of the blood vessels is the other factor that may affect blood flow rate as well as the normal functioning of the heart. Reduction of blood cells radii always occurs as a result of contraction of the muscular wall of the vessels, particularly the large arteries and small arterioles (Campbell, Dawes, Fishman, & Hyman, 1967). When blood vessels constrict, the flow of blood is restricted or decreased, thus, increasing vascular resistance. Vasoconstriction of the blood vessels thus increases heart rate, stroke volume and thus the cardiac output. The more constricted arterioles are, the greater their resistance to blood flow and the higher the blood pressure. Constriction of arterioles increases blood pressure because more pressure is needed to force blood through the narrower space. The narrowing of the blood vessels results in higher blood pressure which has the effect of resulting in pumping of blood further into the body by the heart which may lead to overworking of the heart. However, vasoconstriction results in less blood flow to other organs which may result in failure of vital body organs.

Effect of Blood Pressure on Blood Flow Rate

Blood pressure is influenced by blood volume as well as radii of blood vessels among other factors. High blood pressure usually results in elevated levels of blood flow rate and is usually attributed to structural narrowing of small arteries and arterioles, although a reduction in the number or density of capillaries may also contribute (Zhong, Burns, Song, Ping-Chui, & Petrig, 2011). High blood pressure makes the heart to work harder than normal to circulate blood through the blood vessels which may bring several heart complications. The effects of increased blood pressure to the heart are adverse. These include decreased peripheral venous compliance which may increase venous return, increase cardiac preload and, ultimately, cause diastolic dysfunction.