Page 24, hemodynamics, Dr. D. Penney

Resistance (continued..)

Most of the vascular resistance in the systemic circulation is found on the arterial side of the circulation. Including the capillaries with the arteries, arterioles, etc., this is about 93% of the total resistance. The venous side only has about 7% of the total vascular resistance. Looking in detail at the arterial side, the arterioles (41%) and capillaries (27%) represent the largest amount of resistance.

The major arteries represent a somewhat smaller fraction of the total resistance. The large resistance of the arterioles is a result of their essential role in the localized control of blood flow, while the large resistance posed by capillaries is primarily a result of their very small caliber - a smaller diameter in most cases than that of erythrocytes.


Module 7

Module 5