Functional classification of blood vessels
Functionally, the blood vessels can be classified into the following five groups.
(a) Distributing vessels, including arteries;
(b) Resistance vessels, including arterioles and precapillary sphincters;
(c) Exchange vessels, including capillaries, sinusoids, and postcapillary venules;
(d) Reservoir (capacitance) vessels, including larger venules and veins; and
(e) Shunts, including various types of anastomoses.