Shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal
The function of Shrapnell’s membrane (pars flaccida; PF) in middle-ear mechanics is still an enigma, though numerous proposals have been put forward, e.g. protection of pars tensa, equalizing of middle-ear pressure, sound transmission, and the site of origin of otitis media. In this study the PF was...
Published in: | The Journal of Laryngology & Otology |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press (CUP)
2003
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1258/002221503770716151 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022215103001981 |
id |
crcambridgeupr:10.1258/002221503770716151 |
---|---|
record_format |
openpolar |
spelling |
crcambridgeupr:10.1258/002221503770716151 2023-05-15T16:34:49+02:00 Shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal Stenfors, Lars-Eric Bye, Helga-Marie Tikkakoski, Tapani 2003 http://dx.doi.org/10.1258/002221503770716151 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022215103001981 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms The Journal of Laryngology & Otology volume 117, issue 10, page 756-762 ISSN 0022-2151 1748-5460 Otorhinolaryngology General Medicine journal-article 2003 crcambridgeupr https://doi.org/10.1258/002221503770716151 2022-04-07T08:09:40Z The function of Shrapnell’s membrane (pars flaccida; PF) in middle-ear mechanics is still an enigma, though numerous proposals have been put forward, e.g. protection of pars tensa, equalizing of middle-ear pressure, sound transmission, and the site of origin of otitis media. In this study the PF was studied in a mammal (the hooded seal) which exposes itself to extreme pressure differences (from 1 to 100 atmospheres) when diving. Formaldehyde-fixed temporal bones obtained from newborn, one-year-old, and adult seals (three of each) were cleansed and decalcified in 10 per cent EDTA. The lateral wall of the middle-ear cavity, including the whole tympanic membrane with its bony surroundings, was then excised and photodocumented. Thin sections were cut parallel with, and perpendicular to, the handle of the malleus, stained with haematoxylin-eosin, toluidine blue or Giemsa stain and examined under a light microscope. One seal head was subjected to high resolution computerized tomography (HRCT) before sectioning. The PF was observed to be a narrow fissure measuring a maximum of 0.8 mm between processus brevis of the malleus and the notch of Rivinus in pars squamosa (pars tensa diameter 10–12 mm). It seems unlikely that the PF of the hooded seal participates in pressure equalization in the middle ear. The main function of the lateral wall of the attic, including the minimal PF, appears to be to protect the middle-ear ossicles and allow movement of the malleus. Article in Journal/Newspaper hooded seal Cambridge University Press (via Crossref) The Handle ENVELOPE(161.983,161.983,-78.000,-78.000) The Journal of Laryngology & Otology 117 10 756 762 |
institution |
Open Polar |
collection |
Cambridge University Press (via Crossref) |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Otorhinolaryngology General Medicine |
spellingShingle |
Otorhinolaryngology General Medicine Stenfors, Lars-Eric Bye, Helga-Marie Tikkakoski, Tapani Shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal |
topic_facet |
Otorhinolaryngology General Medicine |
description |
The function of Shrapnell’s membrane (pars flaccida; PF) in middle-ear mechanics is still an enigma, though numerous proposals have been put forward, e.g. protection of pars tensa, equalizing of middle-ear pressure, sound transmission, and the site of origin of otitis media. In this study the PF was studied in a mammal (the hooded seal) which exposes itself to extreme pressure differences (from 1 to 100 atmospheres) when diving. Formaldehyde-fixed temporal bones obtained from newborn, one-year-old, and adult seals (three of each) were cleansed and decalcified in 10 per cent EDTA. The lateral wall of the middle-ear cavity, including the whole tympanic membrane with its bony surroundings, was then excised and photodocumented. Thin sections were cut parallel with, and perpendicular to, the handle of the malleus, stained with haematoxylin-eosin, toluidine blue or Giemsa stain and examined under a light microscope. One seal head was subjected to high resolution computerized tomography (HRCT) before sectioning. The PF was observed to be a narrow fissure measuring a maximum of 0.8 mm between processus brevis of the malleus and the notch of Rivinus in pars squamosa (pars tensa diameter 10–12 mm). It seems unlikely that the PF of the hooded seal participates in pressure equalization in the middle ear. The main function of the lateral wall of the attic, including the minimal PF, appears to be to protect the middle-ear ossicles and allow movement of the malleus. |
format |
Article in Journal/Newspaper |
author |
Stenfors, Lars-Eric Bye, Helga-Marie Tikkakoski, Tapani |
author_facet |
Stenfors, Lars-Eric Bye, Helga-Marie Tikkakoski, Tapani |
author_sort |
Stenfors, Lars-Eric |
title |
Shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal |
title_short |
Shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal |
title_full |
Shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal |
title_fullStr |
Shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal |
title_full_unstemmed |
Shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal |
title_sort |
shrapnell’s membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal |
publisher |
Cambridge University Press (CUP) |
publishDate |
2003 |
url |
http://dx.doi.org/10.1258/002221503770716151 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022215103001981 |
long_lat |
ENVELOPE(161.983,161.983,-78.000,-78.000) |
geographic |
The Handle |
geographic_facet |
The Handle |
genre |
hooded seal |
genre_facet |
hooded seal |
op_source |
The Journal of Laryngology & Otology volume 117, issue 10, page 756-762 ISSN 0022-2151 1748-5460 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1258/002221503770716151 |
container_title |
The Journal of Laryngology & Otology |
container_volume |
117 |
container_issue |
10 |
container_start_page |
756 |
op_container_end_page |
762 |
_version_ |
1766024853143420928 |