The comparative anatomy of the pig middle ear cavity: a model for middle ear inflammation in the human?

This study was undertaken to develop a functional model of otitis media with effusion (OME) in the pig (Sus scrofa), with the purpose of investigating the origin of lymphocytes populating the middle ear during the course of an inflammatory process. The relevance of the model to the human condition of OME is to a large extent dependent on the anatomical and physiological similarities between the middle ear cavity and the pharyngeal lymphoid tissue of the pig and man. Anatomical specimens were collected from 7 young Large White pigs to determine the gross anatomy of the middle ear cavity and the histological characteristics of the middle ear mucosa. It was found that the anatomy of the 3 parts of the middle ear cavity in man and in the pig is broadly similar, although some minor differences were observed. The porcine eustachian tube was seen to be cartilaginous throughout its length in contrast to the part osseous, part cartilaginous structure found in man; the porcine ossicles were slightly different in shape to those of man and the air cell system was situated inferior to the tympanic cavity in the pig as opposed to posteriorly in man. This paper describes the structure and morphology of the pig middle ear cavity and compares and contrasts it with that of man. The minor differences observed are of anatomical importance but do not diminish the usefulness of the pig middle ear cleft as a potential model for human middle ear disorders.

[1]  S. R. Rood,et al.  Comparison of the Anatomy of the Eustachian Tube in the Rhesus Monkey (Macaca Mulatto) and Man , 1980 .

[2]  J. Youmans,et al.  NUTRITIONAL deficiencies. , 1959, Laboratory investigation; a journal of technical methods and pathology.

[3]  Raquel Sister.  [The ear]. , 1966, Epheta; revista de enfermeria y accion social.

[4]  K B Hüttenbrink,et al.  The Middle Ear , 2013, Springer Handbook of Auditory Research.

[5]  T. C. Jones,et al.  Eye and Ear , 1991, Monographs on Pathology of Laboratory Animals.

[6]  L. Brain.  The Nervous System , 1963, Nature.

[7]  A. Ryan,et al.  Lymphocyte circulation to the middle ear. , 1990, Acta oto-laryngologica.

[8]  Howard E. Evans,et al.  Miller's anatomy of the dog , 1979 .

[9]  A. Ryan.  Immune-Mediated Otitis Media in an Animal Model , 1988, The Annals of otology, rhinology & laryngology. Supplement.

[10]  P. McCarthy.  The Anatomy of the Domestic Animals , 1983 .

[11]  H. C. Cook,et al.  Manual of Histological Techniques , 1984 .