Posted: March 24th, 2023

The Blood and Cardiovascular Physiology

Blood pressure

Blood pressure measures the optimal functioning of the cardiovascular system. The body requires a sufficiently high blood pressure to pump enough blood to all organs. The optimal blood pressure ensures that adequate blood and nutrients are supplied to the organs to achieve proper functionality. However, very low blood pressure can cause inadequate blood flow and nutrients to the organs, while very high blood pressure can damage blood vessels. Thus, the cardiovascular system should operate optimally to ensure control over the pressure at which blood flows. While numerous mechanisms control the pressure, the discussion focuses on Cardiac output and peripheral resistance due to their relative importance.

Factors that Affect Blood Pressure

The rate at which blood flows through blood vessels is blood pressure. The formula for calculating the rate is:

“Blood pressure = Flow x Resistance

Mean arterial blood pressure = cardiac output x total peripheral resistance” (Mayet & Hughes, 2003, p. 1105).

According to the calculation, the flow of the blood is influenced by the two variables.

Cardiac Output

The concept suggests the blood volume that flows from the heart to the body through ventricles. The blood volume is measured in the number of liters that flow every one minute. Cardiac output should remain at optimal levels for proper flow of blood. When the amount of blood pumping through the vessels rises, a person experiences increased heart rate. Another potential situation is an increase in stroke volume.  The process also causes blood pressure to increase (a high blood pressure condition) (Stanistreet et al., 2020). Some of the factors responsible for the increase in cardiac output and the high pressure that blood flows are sympathetic stimulation and thyroid hormones.

There are other influencers of low cardiac output that cause the rate at which blood flows to decline. Notably, the situation causes low blood pressure by reducing arterial pressure and blood flow. Parasympathetic stimulation and an increase or decrease in the level of potassium ions affect the outcome. For example, according to Magder (2018), cardiac output can also occur when the sympathetic nervous system is activated and stimulates the atrioventricular (AV) and sinoatrial (SA) nodes. When the two nodes activate, a person experiences an increase in cardiac output, which declines when the parasympathetic nervous structure is activated.

Total peripheral resistance

Total peripheral resistance (TPR) suggests the area present for the flow of blood through the vessels. If the area is reduced, the pressure of the blood will increase. The components that support blood flow should be compliant enough to allow changes in content (the blood). The body could have high-level-of-compliance arteries that better persevere the flow. Such arteries prevent a high level of resistance or high BP (Stanistreet et al., 2020). Compared to arteries, veins have a higher level of compliance and can accommodate more blood. Compliance could occur when a person has a condition affecting the cardiovascular system. In such a condition, arteries stiffen (leading to atherosclerosis or arteriosclerosis) and low blood pressure due to the resistance. The situation can cause higher pressure in the vessels and a low flow of blood. The sympathetic nervous system plays a key role in regulating peripheral resistance, hence, blood flow. Changes in total peripheral vascular resistance can also result from changes in plasma concentration of the endothelial hormones adrenomedullin and endothelin-1 (Magder, 2018). Thus, the hormonal levels should be ideal for the optimal flow of blood.

Conclusion

Optimal blood pressure is necessary for the ideal functions of the organs in the body. Thus, the two factors should function optimally to ensure adequate flow to all organs. Any changes can increase or reduce blood pressure, causing diseases and illnesses.