Development of the Round Window and its Membrane in Human Embryos
1982 Volume 28 Issue 5Supplement3 Pages 845-849
Details
1982 Volume 28 Issue 5Supplement3 Pages 845-849
Observations were made on the development of the round window and its membrane in human embryos. Materials subjected to this study were nine fetuses of 8-36 weeks with C. R. length of 20.7mm, 50.5mm, 60.0mm, 72.0mm, 84.0mm, 155.0mm, 184.0mm, 205.0mm, and 313.0mm respectively. After these materials were fixed with formalin and embedded in paraffin, serially sliced specimens of 5 Am were prepared. The following findings were obtained from this study:
1. Crista semilunaris located at the bottom of the Niche of the round window protruded from the prominentia utriculoampullaris inferior of the canaliculicular part, and was shaped by ossification of cartilage in about 22 weeks.
2. Niche of the round window was related to the hiatus tympanomeningealis, which was the passageway from the cranial cavity to the middle ear.
3. The round window membrane was partly produced by the dura-like structure lining cell, which surrounded the cochlear aqueduct and glossopharyngeal nerve.
