Tonsilla Paraepiglottica in the Bulgarian White × Landrace Pig Crosses - Morphological Traits and Some Morphometrical Investigations

The data about the topography and morphology of the paraepiglottic tonsil (tonsilla paraepiglottica; TPE) in pigs are not enough. The purpose of the present investigation was to determine its topography, morphological traits and some morphometric parameters in Bulgarian White × Landrace pig crosses. It was found that TPE was situated in pars laryngea pharyngis, dorsolaterally to vallecula epiglottica on the lateral syrface of lig. thyroepiglotticum. It is a paired macroscopically visible formation with grooves and the following dimensions (mean ± SEM): length – 15.8±0.4 mm in male and 16.2±0.4 in female; width –8.3 ± 0.1 mm in male and 8.2±0.1 mm in female. The shape of the tonsil is mainly elliptical, and in some instances – oval. It is sharply delineated and prominated over the adjacent tissues. On longitudinal sections, the number of lymph nodules was 75.0±0.9 in male and 76.2±0.9 in female pigs, whereas on transverse sections –33.4 ± 0.9 and 34.9±0.9 respectively. The stratified epithelium of the tonsil located on the part of recessus piriformis, was infiltrated with lymphocytes at some areas. The tonsillar crypt numbers on longitudinal sections were 6.6±0.2 and 6.8±0.2 in male and female pigs, respectively, and on transverse sections 6.5 ± 0.1 (male) and 6.4±0.1 (female). The base of the tonsil was differentiated from adjacent tissues by a well-defined connective tissue capsule.