scholarly journals Paleoneuroanatomy of the aetosaur Neoaetosauroides engaeus (Archosauria: Pseudosuchia) and its paleobiological implications among archosauriforms

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5456 ◽  
Author(s):  
M. Belen von Baczko ◽  
Jeremías R.A. Taborda ◽  
Julia Brenda Desojo
Keyword(s):  
Inner Ear ◽  
Middle Ear ◽  
Cranial Nerves ◽  
Direct Examination ◽  
Internal Morphology ◽  
New Information ◽  
Chinle Formation ◽  
Resin Cast

The paleoneuroanatomy of pseudosuchian archosaurs is poorly known, based on direct examination of the internal morphology of braincases and a few artificial endocasts. Among aetosaurs, only one endocast has been described almost a century ago by Case (1921) corresponding to Desmatosuchus spurensis from the Chinle Formation (Norian) of Texas, US, based on a resin cast. Here, we describe the first natural endocast of an aetosaur, Neoaetosauroides engaeus from the Los Colorados Formation (Norian) of NW Argentina, and also developed the first digital endocast of this taxon including the encephalon, cranial nerves, inner ear, and middle ear sinuses. The neuroanatomy of Neoaetosauroides engaeus exhibits several differences from that of Desmatosuchus spurensis despite their phylogenetic proximity, which may be a reflection of their different habits. The information provided by the endocasts of Neoaetosauroides engaeus about its olfactory region and the orientation of its head, based on the inclination of the inner ear, could support the proposal for an animalivorous diet, instead of an herbivorous one as in most aetosaurs. The new information here obtained contributes to the knowledge of the neuroanatomical diversity of archosauriforms and more specifically among pseudosuchians and their paleobiological roles in the Triassic continental communities.

A new troodontid (Dinosauria, Theropoda) braincase from the Dinosaur Park Formation (Campanian) of Alberta

1993 ◽  
Vol 30 (10) ◽  
pp. 2231-2247 ◽  
Author(s):  
Philip J. Currie ◽  
Xi-Jin Zhao
Keyword(s):  
Inner Ear ◽  
Computerized Tomography ◽  
Middle Ear ◽  
Lateral Surface ◽  
Ct Scans ◽  
Internal Anatomy ◽  
New Information ◽  
Close Relationship ◽  
Dinosaur Park Formation ◽  
The Brain

A new, well-preserved specimen of Troodon formosus is the first to reveal the internal anatomy of the lower part of the braincase. In addition to providing new information on the brain of this highly encephalized dinosaur, the uncrushed bones clear up anatomical details left obscure by earlier studies. Computerized tomography (CT) scans reveal the nature of the inner ear and the course of the pneumatic ducts diverging from the middle ear. Evidence is presented to show that four of the five periotic pneumatic systems found in bird skulls are present in Troodon. The anterior tympanic recess is the most elaborate system, and diverticula from each side extend anteriorly, dorsally and, posteriorly from the middle ear. The posterior tympanic recess is located within the paroccipital process and the basioccipital, but the pneumatopore posterolateral to the stapedial recess is secondarily closed. The dorsal periotic sinus is represented by a smooth-surfaced concavity on the lateral surface of the prootic. The position of a pneumatic recess in this region is demonstrated by the presence of a pneumatopore in the quadrate. Diverticula from the anterior and posterior tympanic recesses are connected within braincase bones, and a possible pneumatopore in the prootic may connect these to the dorsal tympanic recess. The pneumatic condition of the troodontid articular is unknown. Contralateral connections of the sinus systems have been used to argue for a close relationship between birds and crocodiles, but their presence in this specimen suggests that they appeared more than once in archosaurs or that they are plesiomorphic for crocodiles, dinosaurs, and birds. Cranial pneumaticity cannot be used by itself to resolve the interrelationships of crocodiles, theropods, and birds, but other characters suggest derivation of birds from theropods.

Morphologic Changes in the Inner Ear of Chinchilla Laniger after Middle Ear Administration of Gentamicin in a Sustained-Release Vehicle

1999 ◽  
Vol 120 (5) ◽  
pp. 643-648 ◽  
Author(s):  
Michael E. Hoffer ◽  
Ben J. Balough ◽  
Richard D. Kopke ◽  
Jenifer Henderson ◽  
Michael Decicco ◽  
...  
Keyword(s):  
Sustained Release ◽  
Inner Ear ◽  
Middle Ear ◽  
Morphologic Changes

Study of Toynbee Phenomenon by Combined Intranasopharyngeal and Tympanometric Measurements

1988 ◽  
Vol 97 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Yehuda Finkelstein ◽  
Yuval Zohar ◽  
Yoav P. Talmi ◽  
Nelu Laurian
Keyword(s):  
Middle Ear ◽  
Negative Pressure ◽  
Pressure Change ◽  
Positive Pressure ◽  
New Information ◽  
Pressure Changes ◽  
Rapid Pressure

The Toynbee maneuver, swallowing when the nose is obstructed, leads in most cases to pressure changes in one or both middle ears, resulting in a sensation of fullness. Since first described, many varying and contradictory comments have been reported in the literature concerning the type and amount of pressure changes both in the nasopharynx and in the middle ear. In our study, the pressure changes were determined by catheters placed into the nasopharynx and repeated tympanometric measurements. New information concerning the rapid pressure variations in the nasopharynx and middle ear during deglutition with an obstructed nose was obtained. Typical individual nasopharyngeal pressure change patterns were recorded, ranging from a maximal positive pressure of + 450 to a negative pressure as low as −320 mm H2O.

Effects of Platelet Activating Factor on the Tubotympanic Mucosa and Inner Ear in the Guinea Pig

1998 ◽  
Vol 107 (10) ◽  
pp. 876-884 ◽  
Author(s):  
Yoshiharu Ohno ◽  
Yoshihiro Ohashi ◽  
Hideki Okamoto ◽  
Yoshikazu Sugiura ◽  
Yoshiaki Nakai
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Inner Ear ◽  
Otitis Media ◽  
Middle Ear ◽  
Otitis Media With Effusion ◽  
Platelet Activating Factor ◽  
Sensorineural Hearing ◽  
Ciliary Activity ◽  
Middle Ear Mucosa

The effect of platelet activating factor (PAF) was studied to elucidate its role in the pathogenesis of otitis media and sensorineural hearing loss. The PAF alone did not induce a reduction of ciliary activity of the cultured middle ear mucosa. However, a dose-dependent decrease in ciliary activity was observed in the presence of the medium containing both PAF and macrophages. Intravenous injection of PAF did not induce dysfunction of the mucociliary system or morphologic changes of epithelium in the tubotympanum, but cytoplasmic vacuolization and ballooning were observed in the inner ear within 1 hour after injection of PAF. In contrast, intratympanic injection of PAF induced mucociliary dysfunction and some pathologic changes in the tubotympanum. Intratympanic inoculation of PAF induced no pathologic findings in the inner ear. These results suggest that PAF is at least partially involved in the pathogenesis of certain middle ear diseases such as otitis media with effusion. Additionally, PAF might be involved in the pathogenesis of some types of unexplained sensorineural hearing loss.

Common drugs used in ENT

2009 ◽  
pp. 347-350
Author(s):  
Rogan Corbridge ◽  
Nicholas Steventon
Keyword(s):  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Otitis Externa ◽  
Round Window ◽  
Acid Reflux ◽  
Tympanic Membrane Perforation ◽  
Active Infection ◽  
Middle Ear Mucosa ◽  
Membrane Perforation

Drugs used in the ear 348 Drugs used in the nose 349 Drugs used in the treatment of acid reflux 350 This group of drugs is widely used for the treatment of otitis externa. Otitis externa 2 drops tds for 10 days Presence of grommet or tympanic membrane perforation due to aminoglycoside ototoxicity in the inner ear. Risk thought to be low in the presence of active infection where the middle-ear mucosa is swollen and the antibiotic is unlikely to reach the inner ear via the round window...

A newly discovered skull of the temnospondyl amphibian Dendrerpeton acadianum Owen

1987 ◽  
Vol 24 (4) ◽  
pp. 796-805 ◽  
Author(s):  
Stephen J. Godfrey ◽  
Anthony R. Fiorillo ◽  
Robert L. Carroll
Keyword(s):  
Inner Ear ◽  
Posterior Margin ◽  
Functional Relationship ◽  
Impedance Matching ◽  
Three Dimensional ◽  
Natural Position ◽  
Lower Jaw ◽  
New Information ◽  
Early Tetrapods ◽  
Supporting Element

A virtually complete three-dimensional skull of a subadult of the temnospondyl amphibian Dendrerpeton acadianum provides new information on the structure of the palate and lower jaw. The left stapes appears to lie in a natural position on the quadrate ramus of the pterygoid. The proportionately large otic ossicle probably precluded it from having acted as a transmitter of airborne vibrations from a tympanum to the inner ear. The use of the term "otic notch" should be restricted to amphibians or reptiles in which the embayment of the posterior margin of the cheek is accompanied by the presence of a slender rod-like stapes that could have functioned as part of an impedance matching system. In those species in which a notch is present but the stapes is a massive "supporting" element, the term "squamosal embayment" should be used, rather than "otic notch." The squamosal embayment in early tetrapods may have been inherited directly from their fish ancestors and had no functional relationship to hearing.

scholarly journals Study on the Prosthesis Structural Design and Vibration Characteristics Based on the Conduction Effect of Human Middle Ear

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Wu Ren ◽  
Huijuan Yan ◽  
Yi Yu ◽  
Jinghong Ren ◽  
Jinlong Chang ◽  
...  
Keyword(s):  
Frequency Response ◽  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Transmission Function ◽  
Ossicular Chain ◽  
Sound Signal ◽  
Sound Perception ◽  
Response Characteristics ◽  
Middle Ear Prosthesis

As a bridge from the sound signal in the air to the sound perception of the inner ear auditory receptor, the tympanic membrane and ossicular chain of the middle ear transform the sound signal in the outer ear through two gas-solid and solid-liquid conversions. In addition, through the lever principle formed by three auditory ossicle structure, the sound was concentrated and amplified to the inner ear. However, the sound transmission function of the middle ear will be decreased by disease, genetic, or trauma. Hence, using middle ear prosthesis to replace the damaged ossicles can restore the conduction function. The function realization of middle ear prosthesis depends on the vibration response of the prosthesis from the tympanic membrane to the stapes plate on the human auditory perception frequency, which is affected by the way the prosthesis combined with the tympanic membrane, the material, and the geometric shape. In this study, reasonable prosthetic structures had been designed for different types of ossicular chain injuries, and the frequency response characteristics were analyzed by the finite element method then. Moreover, in order to achieve better vibration frequency response, a ball structure was designed in the prosthesis to simulate its amplification function. The results showed that the middle ear prostheses constructed by different injury types can effectively transfer vibration energy. In particular, the first- and second-order resonant frequencies and response amplitudes are close to each other when ball structure models of different materials are added. Instead, the resonance frequency of the third stage formed by aluminum alloy ball materials is larger than that of the other two, which showed good response features.

scholarly journals Influence of Middle Ear Immune Response on the Immunological State and Function of the Inner Ear

1992 ◽  
Vol 102 (2) ◽  
pp. 177???181 ◽  
Author(s):  
B. Gloddek ◽  
Kerstin Lamm ◽  
K. Haslov
Keyword(s):  
Immune Response ◽  
Inner Ear ◽  
Middle Ear ◽  
And Function

scholarly journals Thyroid Hormone Receptors Control Developmental Maturation of the Middle Ear and the Size of the Ossicular Bones

Endocrinology ◽  
2012 ◽  
Vol 153 (3) ◽  
pp. 1548-1560 ◽  
Author(s):  
Emily A. Cordas ◽  
Lily Ng ◽  
Arturo Hernandez ◽  
Masahiro Kaneshige ◽  
Sheue-Yann Cheng ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Inner Ear ◽  
Middle Ear ◽  
Hormone Receptors ◽  
Dominant Negative ◽  
Thyroid Hormone Receptors ◽  
Auditory Thresholds ◽  
Auditory Development ◽  
Genes Encoding

Thyroid hormone is critical for auditory development and has well-known actions in the inner ear. However, less is known of thyroid hormone functions in the middle ear, which contains the ossicles (malleus, incus, stapes) that relay mechanical sound vibrations from the outer ear to the inner ear. During the later stages of middle ear development, prior to the onset of hearing, middle ear cavitation occurs, involving clearance of mesenchyme from the middle ear cavity while the immature cartilaginous ossicles attain appropriate size and ossify. Using in situ hybridization, we detected expression of Thra and Thrb genes encoding thyroid hormone receptors α1 and β (TRα1 and TRβ, respectively) in the immature ossicles, surrounding mesenchyme and tympanic membrane in the mouse. Thra+/PV mice that express a dominant-negative TRα1 protein exhibited deafness with elevated auditory thresholds and a range of middle ear abnormalities including chronic persistence of mesenchyme in the middle ear into adulthood, markedly enlarged ossicles, and delayed ossification of the ossicles. Congenitally hypothyroid Tshr−/− mice and TR-deficient Thra1−/−;Thrb−/− mice displayed similar abnormalities. These findings demonstrate that middle ear maturation is TR dependent and suggest that the middle ear is a sensitive target for thyroid hormone in development.

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