The Microanatomy of the Palatine Tonsils of the One‐Humped Camel (Camelus dromedarius)

Abstract

Tonsils form a first line of defense against foreign antigens and are also a route of entry and a replication site for some pathogens. The palatine tonsils are the largest of all the tonsils. Despite their general importance, little is known about the microanatomy of the palatine tonsils of the one-humped camel. Palatine tonsils of 10 clinically healthy male camels were obtained directly after slaughtering for human consumption. The tonsils were examined macroscopically and by light, scanning, and transmission electron microscopy. Palatine tonsils had the unique form of several spherical macroscopic nodules protruding into the pharyngeal lumen. These spherical masses were numerous and close together in the lateral oropharyngeal wall, with a few solitary nodules in the dorsal wall. Each nodule had one or two apical openings to crypts, and was enclosed by an incomplete connective tissue capsule and covered apically with stratified squamous keratinized epithelium. The tonsillar crypt was lined with stratified squamous non keratinized epithelium. Several lymphocytes infiltrated the epithelial layer, forming patches of reticular epithelium. Lymphoid follicles with obvious germinal centers extended under the epithelial surface. Diffusely localized lymphocytes were seen in the interfollicular region. High endothelial venules, dendritic cells, macrophages, and plasma cells were observed among these lymphocytes. The unique arrangement of palatine tonsils in separate units with individual crypts results in a very large surface exposed to antigen and indicates a significant immunological role of palatine tonsils in the camel.

Histological Structure of the Lingual Tonsils of the Buffalo Calf (Bos bubalus)

“…The lymphoid tissue constitutes the majority of tonsillar structure and is organized into lymphoid follicles and interfollicular diffusely scattered lymphoid cells. This is similar to equine lingual tonsils (Kumar and Timoney, 2005b) and also palatine tonsils of other species as equine (Kumar and Timoney, 2005c), camel (Zidan and Pabst, 2009) and buffalo (Zidan and pabst, 2011). The lymph follicles have ill developed germinal centers and a small corona facing the crypt epithelium.…”

“…The buffalo farming increased in the past decades in both Italy and overseas due to increase the mozzarella consumption (Borghese, 2013). Tonsils form a first line of defense against foreign antigens and form Waldeyer's ring (Zidan and Pabst, 2009) which play a key role in initiating immune responses against antigens entering the body through the mouth (Brandtzaeg, 1984). The tonsils classified into two types according to the surface epithelium: tonsils without crypt (e.g., palatine tonsil of the dog and cat) and tonsils with crypt which have deep surface invaginations, referred to tonsillar fossulae (crypts) these invaginations allow for a high concentration of lymphatic tissue in a given area (e.g., lingual tonsil in the horse, ruminants and pig; palatine tonsil in the horse and ruminants) (Dellmann and Brown, 1976).…”

Temporospatial characterization of the bronchus associated lymphoid tissue (BALT) of the one humped camel (Camelus dromedarius)

“…Depending on histological finding, the specimens of the 4 years camels (the camels with well-developed BALT) were processed as outlined by Woods and Stirling ( 2019 ). For details, see Zidan and Pabst ( 2009 ). Semithin sections (1μm) were stained with toluidine blue and examined with the light microscope.…”

Yak (Bos grunniens) Tonsils: Morphological Description and Expression of IgA and IgG

“…In cattle tuberculosis (Cassidy et al, 1999), and cattle spongiform encephalopathy (Caramelli et al, 2003;Wells et al, 2005), tonsils are strategic entry points for pathogens. Therefore, increasing researchers to enter the field of mucosal immunology were interested in the morphological characteristics of tonsils in various species, including the humans (Nave et al, 2001;Idris et al, 2013;Jovi c et al, 2015), ovine (Cocquyt et al, 2005;Casteleyn et al, 2007Casteleyn et al, , 2008Casteleyn et al, , 2010, camels (Zidan and Reinhard, 2009;Jia et al, 2017), cattles (Manesse et al, 1998;Velinova et al, 2001;Palmer et al, 2009Palmer et al, , 2011Zidan and Pabst, 2011), pigs (Belz and Heath, 1996;Williams and Rowland, 1972;Liu et al, 2012), horses (Kumar and Timoney, 2005), dogs Heath, 1995a, 1995b), and rabbits (Harrison et al, 1970;Oláh and Everett, 1975). Unfortunately, as a special plateau animal, there are no detailed anatomical or histological dates of yak tonsils.…”