Page 70 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 5
VetBooks.ir

Surgery of the ear

Karen M. Tobias and Christine Cain

Anatomy Trauma to the ear results in rupture of these blood vessels
and significant haemorrhage or haematoma formation.
The pinna of the ear gives dogs their distinctive look. The external ear canal is formed by three overlapping
Despite massive phenotypic variation among different tubes. The auricular cartilage, which is funnel-shaped
breeds, the basic structure is the same for all. The auric - at its base, twists and bends to form the majority of the
ular cartilage that forms the pinna is divided into two vertical ear canal and the proximal portion of the horizontal
portions: a flat scapha and a tubular concha. A transverse ear canal. Its base surrounds and overlaps the annular
fold on the concave base of the auricular cartilage, cartilage, a ring of cartilage that forms the majority of the
i
the ant helix, separates the two portions of the pinna. The horizontal ear canal (Figure 5.1). The annular cartilage, in
cartilage of the pinna contains many small perforations that turn, overlaps the external acoustic meatus, a short bony
allow blood vessels and nerves to penetrate from the outer extension of the skull that connects the cartilaginous
concave surface to the inner convex surface of the ear. ear canal to the tympanic cavity. These three tubes are

5.1 Anatomy of the canine external ear.

Pinna

Temporalis muscle

Auricular
cartilage
Vertical canal

Horizontal canal
Osseous external
acoustic meatus
Annular cartilage
Auditory ossicles
Facial nerve
Tympanic membrane
Parotid gland
Tympanic cavity
Tympanic bulla
Mandibular gland

BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, second edition. Edited by Daniel J. Brockman, David E. Holt and Gert ter Haar. ©BSAVA 2018 61

Ch05 HNT.indd 61 03/09/2018 10:12