Morphogenesis of the middle ear ossicles and spatial relationships with the external and inner ears during the embryonic period
| Autor: | Maimi Ozeki-Satoh, Tetsuya Takakuwa, Shigehito Yamada, Aoi Ishikawa, Chigako Uwabe |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Vestibular system Histology Ossicles Incus Malleus Anatomy 030105 genetics & heredity Biology 03 medical and health sciences 030104 developmental biology medicine.anatomical_structure medicine Middle ear Perichondrium Inner ear Ecology Evolution Behavior and Systematics Biotechnology Stapes |
| Zdroj: | The Anatomical Record. 299:1325-1337 |
| ISSN: | 1932-8486 |
| DOI: | 10.1002/ar.23457 |
| Popis: | We describe the three-dimensional morphogenesis of the middle ear ossicles (MEOs) according to Carnegie stage (CS) in human embryos. Seventeen samples including 33 MEOs from CS18 to 23 were selected from the Kyoto Collection. The primordia of the MEOs and related structures were histologically observed and three-dimensionally reconstructed from digital images. The timing of chondrogenesis was variable among structures. The stapes was recognizable as a vague condensation of the mesenchymal cells in all samples from CS18, whereas the malleus and incus were recognizable at CS19. Chondrogenesis of all MEOs was evident in all samples after CS21. The chondrocranium was recognizable in all samples by CS18, and the perichondrium border of the auricular cartilage and otic capsule was distinct in all samples at CS23. At CS19, the MEOs were positioned in the anterior to posterior direction, following the order malleus, incus, stapes, which adjusted gradually during development. The MEOs connected in all samples after CS22. The stapes was located close to the vestibular part of the inner ear, although the basal part was not differentiated into the "footplate" form, even at CS23. The handles of the malleus were close to the tubotympanic recess at CS23, but were distant from the external auditory meatus. Determining the timeline of the formation of MEOs and connection of the external and inner ears can be informative for understanding hearing loss caused by failure of this connection. These data may provide a useful standard for morphogenesis, and will contribute to distinguishing between normal and abnormal MEO development. Anat Rec, 299:1325-1337, 2016. © 2016 Wiley Periodicals, Inc. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text