Anatomical localisation and histology of larynx-associated lymphoid tissue (LALT) in the adult bactrian camel (Camelus bactrianus).

The distribution of lymphoid tissue in the larynx mucosa of the bactrian camel was investigated by means of both macroscopy and microscopy. The results showed that paraepiglottic tonsil was located lateral to the epiglottis in the ventromedial segment of the pharyngeal sidewall. The tonsil was made up of 3 to 8 nodular elevations with 2 or 3 narrow elongated entrances to the underlying crypts. Organised lymphoid tissue was identified in the mucosa of vestibulum laryngis and cavum infraglotticum. Obvious lymphoid follicles (LF) were observed in the false vocal cords (FVC). The results revealed that the paraepiglottic tonsil and larynx-associated lymphoid tissue (LALT) composed the integrated mucosal immune system as an essential component of defence in the camel upper respiratory tract. The morphological findings of LF with germinal centre suggested that FVC may participate in the protection of the larynx of camel.