The structure of the salivary glands is different depending on the species and diet. The glandular secretion can be serous, mucous or mixed. Within the same order, for instance in rodents, there are dissimilarities between the major salivary glands, even if the diet is similar.In this study, we used three chinchillas, slaughtered for their fur. We harvested the major salivary glands which were histologically processed.The parotid gland in chinchilla is highly similar to the one in other mammal species, regarding its general microscopic aspect. It contains only one type of acini (serous) and numerous secretory ducts. On the other hand, the submaxillary gland has a particular type of acini, with a narrow lumen and cells with a round nucleus. They resemble the serous ones, but the glanular aspect of the cytoplasm suggests that the secretion of this gland is different in comparison to the one in the parotid gland. The structure of the sublingual gland in chinchilla is similar to the one in most of the mammals, containing typical mucous acini, with a foamy cytoplasm.The major salivary glands in chinchilla highly resemble those in most of the mammal species. The parotid gland presents serous acini and the sublingual one, typical mixed acini. Instead, the submaxillary gland has a particular aspect: its acini do not present the serous demilune, they resemble the typical serous acini (contain round nuclei), but they are larger.

Epiglottis presents a central axis covered by mucosa. The aim of this study was highlighting the type of epithelium lining the lamb epiglottis. Thus, we histologically processed the epiglottis from 3 lambs. The epithelium lining the whole epiglottis surface is non-keratinized stratified squamous, with different thickness from one side to the other. Hence, on the pharyngeal side the epithelium is twice as thick as the one found on the laryngeal side.

The size of salivary glands, acinar structure, and secretion particularities differ from one species to another and are influenced by diet and environment. In order to investigate whether there are histological or histochemical differences in the salivary glands of animals from the same species, bred in identical conditions of environment and diet, we assessed two laboratory rat strains. The salivary glands from two rat strains were processed for histological and histochemical investigations. Histologically, we noticed differences in the parotid gland: seromucous acini were present in Brown Norway rat and typical serous ones in Wistar rat. Histochemically, we observed that cells in the parotid gland present a moderate PAS-positive reaction only in Wistar rat. In the mandibular gland, the size and shape of the acini were similar, whereas the cytoplasm of acinar and granular duct cells was PAS-positive in both rat strains, but with different intensities. In the sublingual gland, both PAS and Alcian blue reactions were positive in the two rat strains, with a higher intensity in the Brown Norway strain. Our study highlighted intraspecific histological and histochemical differences in salivary glands from two rat strains bred and fed in identical conditions.

The aim of this study was to investigate by histological techniques the structure of urethral epithelium in lambs. In this study, we harvested several fragments (prostatic, membranous and cavernous) from urethra from 5 merino's lambs of 3 months old. The first anatomical segment, the prostatic urethra, is lined by a urinary epithelium. The intermediary layer of this epithelium is formed of 5-6 rows of oval cells. The second segment of urethra has the same type of epithelium but the intermediary layer is formed of 6-7 rows of oval cells. In the last anatomical segment, the penile urethra, the epithelium is the same, but the intermediary layer has 3-4 rows of oval cells. In lambs, the urethra is lined by urinary epithelium. The urethral epithelium does not have the same thickness in all segments. The thinner epithelium it is in the cavernous urethra, the ticker is the membranous urethra.

Mandibular gland ducts’ system in rodents consist of intralobular ducts (intercalated, granular, striated) and interlobular one (main excretory duct). Granular ducts are located between intercalated and striated ducts, being present only in mandibular gland of the mouse, rat, hamster and gerbil. The biological material used for this study was represented by two strains from the same species, three Wistar rats and three Brown Norway rats. After the animals were euthanized, the mandibular glands were harvested and then processed for histological investigations. The tissue fragments were sectioned at 5μm thickness and then stained the sections using Tricrom-Goldners method. Our results emphasize that the granular ducts are well developed; regarding the shape, they are convoluted in both Wistar and Brown Norway rats, without any significant differences between the two strains. In Wistar rat, the granules in granular ducts cells are small to medium in size, with discrete polymorphism. In Brown Norway rat, the cytoplasm is loaded with granules as in Wistar rat, but these are several times larger and more polymorphic.