ostium

(0s’te-um) pl. os’fia [L.]._ A mouth or orifice. o. abdomina’‘le, 0. abdomina'le tu’be uteri’ng, the fimbriated end of an oviduct. Ο. arterio’sum, the auriculoventricular opening. o. atrioventricula’re. Same as o. veno’sum. o. inter’num, the uterine end of an oviduct. o. pharyn’geum tu’b® audit i’ve, the nasopharyngeal end of a eustachian tube. 0. tympan’icum, the tympanic orifice of a eustachian tube. o. tympan’icum tu’be audit i’ve, the tympanic opening of the eustachian tube. 0. uteri’num tu’be uterin’s, the uterine opening of the fallopian tube. o. vagi’ngw, the external orifice of the vagina. o. veno’sum, the venous orifice of the ventricles of the heart.