Graduate Thesis Or Dissertation
 

Anatomy of the osseous external acoustic meatus, middle ear and surrounding soft tissue in llamas (Lama glama)

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/x346d652f

Descriptions

Attribute NameValues
Creator
Abstract
  • Llamas (Lama glama) appear to have predisposing anatomical features for developing otitis media such as a long and narrow external acoustic meatus and a trabecular tympanic bulla. However, there is limited information available about the morphology of the ear in this species. The aim of this study was to evaluate the osseous structures of external acoustic meatus, tympanic cavity and tympanic bulla using CT, and the soft tissue surrounding the ear using dissections. Ten heads were collected from healthy llamas slaughtered for meat production. Using a CT scanner with slices acquired at 1 mm, measurements of the bony structures of the external and middle ear of each head were obtained. The surrounding soft tissue was examined using dissection, a 6-inch protractor and a digital caliper. The osseous external acoustic meatus was ventrally curved with an obtuse angle facing ventrally. Its narrowest portion was located medially at the level of the tympanic annulus. The conformation of the tympanic bulla was the most different in appearance compared to other domestic animals. It was divided into caudo-lateral and caudo-medial processes, body, apex, and stylohyoid fossa to study its morphometry. The interior of the tympanic bulla had a honeycombed structure with pneumatized cells similar to the human's mastoid process. The nerves, vessels, muscles and tendons had the general distribution of those structures in herbivorous domestic animals. The present study supplied new information about the shape and measurements of the osseous external and middle ear and surrounding soft tissue in adult llamas. This study also supplied specific landmarks of the location of these structures in relationship with each other. Based on our observations and measurements, a new surgical approach to perform a tympanic bulla osteotomy was suggested to treat otitis media in llamas.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items