ANATOMIC CONSIDERATIONS ON THE MIDDLE EAR IN DOGS

Authors

  • Carmen Berghes
  • Mircea Cucoanes
  • Daniel Cuca
  • Cristina Dinu

Abstract

The middle ear is a bone cavity coated with mucous and full of air. This cavity is implanted inside the temporal bone between the ear drum. Inside the cavity there are four small bones articulated between them in a chain. The lateral wall is membraneous, formed of the tympanum membrane and of a tympanum ring. The median wall is formed of the stone part of the temporal bone and displays three characteristic anatomic formations: promontory, oval window and round window. The promontory looks like an elongated prominence which separates the oval window from the round one. The oval window or the vestibular window is like a slightly ovoid orifice located dorso-medial from the promontory, by which the vestibule communicates with the middle ear. The round window or the cochlear window is a circular orifice located caudo-lateral from the promontory. It is covered by a membrane called the secondary tympanum, which separates the tympanum cavity from the tympanic ramp of the cochlea. In the ventro-lateral side, the tympanum cavity has the tympanum opening. The acoustic bones, the hammer, the anvil, the lenticular bone and the ladder, are articulated between them and form a chain which connects the tympanum and the vestibular window. The bones are driven by two muscles, the tensor muscle and the ladder muscle. The mucus lining the irregularities inside the cavity is in connection with the pharyngeal mucous by means of  the auditive tube.

References

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Published

2008-12-20

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Articles