The internal urinary sphincter: a double-lop system.
D004210:Dissection; D004707:Endoderm / Q000033:anatomy & histology; D006801:Humans; D008297:Male; D008648:Mesoderm / Q000033:anatomy & histology; D009130:Muscle, Smooth / Q000033:anatomy & histology / Q000502:physiology; D014521:Urethra / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D001743:Urinary Bladder / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000196:embryology / Q000502:physiology; D014554:Urination; D014567:Urography