Histology of Palate and Soft Palate Tonsil of Collared Peccary (Tayassu tajacu)

Abstract

Peccaries are characterized by a prominent skin gland, known as scent gland, which is located in the middle of the rump. These animals are able to survive in a great variety of habitats, from humid tropical forests to semi-arid areas. They are omnivorous animals, and their diet includes fibrous material, vegetables, fruits, small vertebrates and insects. Collared peccary hard palate and soft palate tonsils were studied, macroscopic morphometric data were collected and tissue samples were paraffin-embedded. Sections were stained with HE, Gomori's trichrome and von Kossa; the first two were used to study general organization and the latter to detect calcium deposits. The hard palate showed one incisive papilla followed by several rugae united by a distinct raphe. The hard palate is lined by a keratinised squamous epithelium resting on a dense connective, whereas in the soft palate, the epithelium is parakeratinised and showed lymphocyte infiltration. The palate showed several pacinian corpuscles in the propria-submucosa. Two ovoid-shaped tonsils were found in the soft palate, and several crypts were observed on its surface. The epithelium was highly infiltrated by lymphocytes, and within the crypts, tonsilloliths were frequently observed. The study showed that the general organization of collared peccary palate is similar to other species, but in its oropharynx, only the soft palate tonsil was present and the pacinian corpuscles formed small aggregates.

Structural and Ultrastructural Characteristics of the Red-Rumped Agouti (Dasyprocta leporina—Linnaeus, 1758) Palatine Epithelium

“…Under light microscopic, stratified squamous keratinized epithelium is present throughout the palate and it is similar to other mammals (Teófilo et al, 2014;Mahdy et al, 2018;Ari & Uslu, 2019). The lamina propria shows interdigitating in the hard palate as in dog, pig, rat, rabbit, guinea pig, sheep, buffalo (Sa et al, 2016), Egyptian goat (Mahdy et al, 2018), rocky cavy (Aro et al, 2019), and Anatolian bobcat (Ari & Uslu, 2019).…”

Morphology and histology of the Anatolian bobcat (Lynx lynx) hard palate

“…Histologically, the hard palate consists of layers of keratinized stratified squamous epithelium and submucosa (which contains abundant adipose tissue); it also contains venous plexuses and cavernous tissue, which are supported by collagenous bundles that run in various directions (Teofilo et al, ). Examination of the hard palate with scanning electron microscopy (SEM) revealed its transverse rugae; incisive papilla, which was caudolaterally situated in a C‐shaped groove; microplicae; and hexagonal epithelium cells (Asikainen et al, ; Mahdy et al, ).…”

Lateral palatal foramina do not indicate baleen in fossil whales

“…Accordingly, we suggest that baleen can only be directly inferred for fossil mysticetes that are recovered phylogenetically within crown Mysticeti. Certainly, the discovery of soft tissue preservation in stem mysticetes would better test for presence of baleen; at best, lateral palatal foramina in edentulous mysticetes may represent gingival structures similar to the rugose soft palates observed in extant artiodactyls 39 .…”