function
(1) circuitous pathway (nutrient pathway): ① composition: the pathway of blood from arteriole to posterior arteriole to anterior sphincter of capillary → true capillary → venule; Function: It is the main place for material exchange between blood and tissue cells.
(2) Direct access: ① Composition: the access of blood from arteriole to posterior arteriole to capillary and then to venule; ② Function: Promote rapid blood return, which is common in skeletal muscle.
(3) Arteriovenous short circuit: ① Composition: the passage of blood from arterioles to arteriovenous anastomosis branches and then to venules; ② Function: regulate body temperature. This way is widely distributed in the skin.
Please see the details.