<<
>>

Histopatholog y of the External Ear Canal

The epithelium of the external auditory meatus is composed of components similar to those of normal skin. The stratum corneum is the outermost layer; keratinocytes make up this layer of squamous anuclear cells.

There are no rete ridges in the epithe­lium of the ear canal. The sebaceous glands are the outermost glands; they become progressively more numerous deeper into the meatus. Underlying the sebaceous glands are simple, coiled, tubular, apocrine glands called ceruminous glands, with ducts that open directly into hair follicles or onto the surface of the ear canal (Figure 10-1). During inflammatory reactions, sebaceous glands become hyperactive and hyper­plastic; the ceruminous glands become dilated, thickened, and filled with secretions (Figure 10-2). Under normal physiologic conditions, ceruminous secretions (cerumen) combine with sebum produced by the sebaceous glands and epidermal debris to form earwax, the normal secretion of the ear.

<< | >>
Source: Gotthelf Louis N.. Small Animal Ear Diseases: An Illustrated Guide. 2nd ed. — Saunders,2004. — 384 p.. 2004
More medical literature on Medic.Studio

More on the topic Histopatholog y of the External Ear Canal: