| ostium pyloricum | The opening between the stomach and the superior part of the duodenum. Synonym: ostium pyloricum, gastroduodenal orifice. (05 Mar 2000) |
|---|---|
| ostium secundum | A secondary opening appearing in the upper part of the septum primum in the sixth week of embryonic life, just prior to the closure of the interatrial foramen primum. Synonym: ostium secundum, secondary interatrial foramen. (05 Mar 2000) |
| ostium trunci pulmonalis | The opening of the pulmonary trunk from the right ventricle, guarded by the pulmonary valve. Synonym: ostium trunci pulmonalis, pulmonary orifice. (05 Mar 2000) |
| ostium tympanicum tubae auditivae | An opening in the anterior part of the tympanic cavity below the canal for the tensor tympani muscle. Synonym: ostium tympanicum tubae auditivae, tympanic opening of eustachian tube. (05 Mar 2000) |
| ostium ureteris | The opening of the ureter in the bladder, situated one at each lateral angle of the trigone; wide gaping of the ostium usually indicates vesicoureteral reflux. Synonym: ostium ureteris, orificium ureteris, ureteral meatus, ureteral opening. (05 Mar 2000) |
| ostium urethrae externum | The slitlike opening of the urethra in the glans penis, the external orifice of the urethra (in the female) in the vestibule, usually upon a slight elevation, the papilla urethrae. Synonym: ostium urethrae externum, external opening of urethra, meatus urinarius, orificium urethrae externum. (05 Mar 2000) |
| ostium urethrae internum | The internal opening or orifice of the urethra, at the anterior and inferior angle of the trigone. Synonym: ostium urethrae internum, internal urethral opening. (05 Mar 2000) |
| ostium uteri | The vaginal opening of the uterus. Synonym: ostium uteri, mouth of the womb, opening of uterus, orificium externum uteri, os uteri externum, ostium uteri externum. (05 Mar 2000) |
| ostium uteri externum | The vaginal opening of the uterus. Synonym: ostium uteri, mouth of the womb, opening of uterus, orificium externum uteri, os uteri externum, ostium uteri externum. (05 Mar 2000) |
| ostium uteri internum | An elongated constriction at the junction of the body and cervix of the uterus. Synonym: isthmus uteri, Guyon's isthmus, orificium internum uteri, os uteri internum, ostium uteri internum. (05 Mar 2000) |
| ostium uterinum tubae | The uterine opening of the oviduct. Synonym: ostium uterinum tubae, ostium internum, uterine opening of uterine tubes. (05 Mar 2000) |
| ostium vaginae | The narrowest portion of the canal, in the floor of the vestibule posterior to the urethral orifice. Synonym: ostium vaginae, orificium vaginae, vaginal opening. (05 Mar 2000) |
| ostium venae cavae inferioris | The orifice through which the inferior vena cava opens into the right atrium. Synonym: ostium venae cavae inferioris, orifice of inferior vena cava. (05 Mar 2000) |
| ostium venae cavae superioris | The point of entry of the superior vena cava into the right atrium. Synonym: ostium venae cavae superioris, orifice of superior vena cava. (05 Mar 2000) |
| ostium venosum cordis | An atrioventricular opening which leads from the right atrium into the right ventricle of the heart. Synonym: ostium atrioventriculare dextrum, ostium venosum cordis. (05 Mar 2000) |