Generally, a pulse pressure should be at least 25 percent of the systolic pressure. For example, an individual with a systolic pressure of 120 mm Hg and a diastolic pressure of 80 mm Hg would have a pulse pressure of 40 mmHg. Pulse PressureĪs shown in Figure 1, the difference between the systolic pressure and the diastolic pressure is the pulse pressure. The graph shows the components of blood pressure throughout the blood vessels, including systolic, diastolic, mean arterial, and pulse pressures. The diastolic pressure is the lower value (usually about 80 mm Hg) and represents the arterial pressure of blood during ventricular relaxation, or diastole.įigure 1. The systolic pressure is the higher value (typically around 120 mm Hg) and reflects the arterial pressure resulting from the ejection of blood during ventricular contraction, or systole. When systemic arterial blood pressure is measured, it is recorded as a ratio of two numbers (e.g., 120/80 is a normal adult blood pressure), expressed as systolic pressure over diastolic pressure.
Components of Arterial Blood PressureĪrterial blood pressure in the larger vessels consists of several distinct components: systolic and diastolic pressures, pulse pressure, and mean arterial pressure.
In clinical practice, this pressure is measured in mm Hg and is usually obtained using the brachial artery of the arm. Blood pressure may be measured in capillaries and veins, as well as the vessels of the pulmonary circulation however, the term blood pressure without any specific descriptors typically refers to systemic arterial blood pressure-that is, the pressure of blood flowing in the arteries of the systemic circulation. One form of hydrostatic pressure is blood pressure, the force exerted by blood upon the walls of the blood vessels or the chambers of the heart. It also discusses the factors that impede or slow blood flow, a phenomenon known as resistance.Īs noted earlier, hydrostatic pressure is the force exerted by a fluid due to gravitational pull, usually against the wall of the container in which it is located. This section discusses a number of critical variables that contribute to blood flow throughout the body. Ventricular contraction ejects blood into the major arteries, resulting in flow from regions of higher pressure to regions of lower pressure, as blood encounters smaller arteries and arterioles, then capillaries, then the venules and veins of the venous system. It is initiated by the contraction of the ventricles of the heart. Discuss several factors affecting blood flow in the venous systemīlood flow refers to the movement of blood through a vessel, tissue, or organ, and is usually expressed in terms of volume of blood per unit of time.Identify and discuss five variables affecting arterial blood flow and blood pressure.Describe the clinical measurement of pulse and blood pressure.Distinguish between systolic pressure, diastolic pressure, pulse pressure, and mean arterial pressure.By the end of this section, you will be able to:
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