Effects of Vasodilation and Arterial Resistance on Cardiac Output

Arteries and veins are vital circulatory system vessels. The role of arteries is to transport blood from the heart to the various organs in the body, whereas the role of veins is to transport blood from the heart to the various organs in the body. The blood that flows through the arteries and veins puts pressure on them. A variety of factors influence arterial and venous blood pressure. Blood volume, cardiac output, peripheral resistance, and vascular flexibility are all factors that influence blood pressure in the arteries and veins.

Cardiac output refers to the amount of blood pumped by the heart per minute. It is dependent on the heart rate and the stroke volume and is obtained by finding the product of the two factors. The unit of measurement of cardiac output is liters/minute. An increase in the cardiac output cause an increased blood flow (Tzeng & Ainslie, 2014). Since it is dependent on stroke volume and the heart rate, an increase in either or both of the two factors will cause the blood pressure to rise (Aliya, 2011).

Blood volume

The blood volume through the arteries and veins influence the blood pressure. An increased blood volume increases the blood pressure and a decrease leads to a lower blood pressure. A high blood volume causes more blood flow and therefore leading to an increased blood pressure (Tzeng & Ainslie, 2014). Similarly, a decrease in blood volume leads to a decreased blood flow and therefore a decreased blood pressure.

Peripheral resistance

Blood pressure is dependent on the resistance of the blood vessels. Some of the factors that influence peripheral resistance are the diameter of arteries and veins, and blood viscosity. Another factor is the total length of the vessels (Anwar, Shalhoub, Lim, Gohel, Davies, 2012). A high peripheral resistance leads to a blood pressure decrease. If it decreases, the blood pressure rises (Aliya, 2011). For example, an increase in blood viscosity increases resistance of the blood vessels hence causing a blood pressure decrease.

Vessel Elasticity

A blood vessel that is more elastic has less blood pressure than that which is less elastic. An artery that is healthy is elastic and therefore expands, leading to blood pressure that is in the normal range. A vessel that is less elastic leads to a high blood pressure because its walls are rigid. Therefore, they become weaker with time because of the increase in blood pressure.

Conclusion

Blood pressure is a major factor in cardiovascular health. It should be in the healthy range to ensure optimum health. Too high or too low blood pressure can cause significant morbidity and mortality. Therefore, it is crucial for all individuals to have blood pressure measurements regularly.

References

Aliya, S. (2011). Effects of Vasodilation and Arterial Resistance on Cardiac Output. Journal of

Clinical and Experimental Cardiology. Retrieved from https://www.omicsonline.org/effects-of-vasodilation-and-arterial-resistance-on-cardiac-output-2155-9880.1000170.php?aid=3452

Anwar, M.A, Shalhoub, J., Lim, C.S., Gohel, M.S., & Davies, A. H. (2012). The Effect of Pressure-Induced Mechanical Stretch on Vascular Wall Differential Gene Expression.

Journal of Vascular Research, 49(6): 463-478.

Tzeng, Y.C., & Ainslie, P.N. (2014). Blood pressure regulation IX: cerebral autoregulation

under blood pressure challenges. European Journal of Applied Physiology, 114(3): 545-

559.