ABSTRACT
The cardiovascular (CV) system provides nutrient delivery and metabolic waste removal throughout the body. Its two component circulations (pulmonary and systemic) are linked in series. The normal path of blood flow is schematically illustrated (1), along with approximate normal pressures. The systemic
circulation contains about 75% of the total blood volume, compared with 25% in the pulmonary circulation. Systemic veins act as storage (capacitance) vessels and contain about 67-80% of the systemic blood volume; 11-15% is held within arteries and 5% within the capillaries1, 2. Blood in the pulmonary
1 Schematic diagram of the cardiovascular system. Examples of normal pressures (mm Hg) in different regions are noted in parentheses: ed = end-diastolic; d = diastolic; m = mean; s = systolic; LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.
