Sphincters in the microvascular system.
D000818:Animals; D001158:Arteries / Q000033:anatomy & histology*; D001163:Arteriovenous Anastomosis / Q000033:anatomy & histology; D002196:Capillaries / Q000033:anatomy & histology*; D008833:Microcirculation; D009130:Muscle, Smooth / Q000033:anatomy & histology