The problem of the internal vesical sphincter.
D000328:Adult; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009130:Muscle, Smooth / Q000033:anatomy & histology; D009626:Terminology as Topic; D014521:Urethra / Q000033:anatomy & histology*; D001743:Urinary Bladder / Q000033:anatomy & histology*