<prompt> The greatest total cross-sectional area in the circulatory system is ofAoaCapillariesVenulesVene cavea  <response>: The greatest cross sectional area in the circulatory system is of capillaries. The total cross-sectional area is minimum for the aoa. Characteristics of Various Types of Blood Vessels in Systemic Circulation: Vessel Lumen Diameter Wall Thickness Approx. Total cross sectional area Cm2 of Blood volume contained Aoa 2.5cm 2mm 4.5 2 Aery 0.4cm 1mm 20 8 Aeriole 30 mcm 1 mcm 400 1 Capillary 5 mcm 1 mcm 4500 5 Venule 20 mcm 2 mcm 4000 54 Vein 0.5cm 0.5mm 40 54 Vena cava 3 cm 1.5mm 18 54 In systemic vessels; there is an aditional 12 in the hea and 18 in the pulmonary circulation. Ref: Ganong;s review of medical physiology 26th edition Pgno: 559 