Gross morphological,histological and scanning electron specifications of the oropharyngeal cavity of the hooded crow (Corvus cornix pallescens)

The present study was carried out on the oropharyngeal cavity of the hooded crow to investigate the gross and microscopic structures via gross anatomy, light microscopy and scanning electron microscopy (SEM). The gross anatomy clarified the elongated triangular shape of the oropharyngeal cavity with a non-protruding tongue with a bifid apex. The lingual body contained median groove rostrally and separated caudally from the root by a transverse papillary crest. The laryngeal mound located posterior to the lingual root, contained midline laryngeal cleft and bounded caudally by a transverse row of pharyngeal papillae. The palate contained choanal cleft rostrally and infundibular slit caudally in addition to five palatine ridges. By light microscopy, the dorsal lingual epithelium was highly keratinised stratified squamous with a lingual nail in the most rostral part of the apex. Then, the thickness of the keratin layer decreased caudally, while in the ventral surface, the lining epithelium became non-keratinised. The entoglossum supported the lingual body and root, but not extended to the apex. The lining epithelium of the palate was also keratinised stratified squamous and became none-keratinised at the oral side of the choanal cleft. There were numerous lobules of polystomatic salivary glands in the lingual root and the palate. SEM revealed the arrangement of different types of papillae covering both the floor and the roof of the oropharynx besides numerous openings of salivary glands in the lingual root, laryngeal mound and the palate. These findings reflect the functional relationship of the oropharyngeal cavity of the hooded crow during feeding.     

Gross Morphometric Studies on the Tongue,Buccal Cavity and Hard Palate of the Fruit Bat (Eidolon helvum)

This study was designed to assess the gross morphometric studies of the tongue, hard palate and buccal cavity of the fruit bat (Eidolon helvum). Sixty bats of both sexes were used for this study. The tongue was excised, and the weight and various linear measurements were determined. Linear measurements were also determined on the hard palate. The gross distribution of the lingual papillae was observed to be the same in both sexes; values obtained for the weight and length of the tongue were higher in the females, although no statistically significant differences were observed (P > 0.05). The number of ridges on the hard palate displayed sexual dimorphism. Results obtained from this study may find application in the field of comparative and clinical anatomy of wildlife and also in feeding physiology.     

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

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.     

Scanning electron microscopic and histological features of the oral cavity of the Egyptian tortoise (Testudo kleinmanni)

This investigation was led to depict the structural and functional adaptations of the oral cavity of herbivorous Egyptian tortoises using scanning electron and light microscopes. The SEM showed that the triangular papillary tongue possessed three conical papillary subtypes: the rectangular conical on the tip, the round conical on the rest of the dorsal lingual surface and the elongated conical on the caudal portion of the lingual wing. The presence of the serrated lips with their valves compensated for the absence of the teeth. The rostral part had a vomeronasal opening while the middle part had the choana, but the caudal part had numerous openings of the salivary glands. There are three palatine folds: a single median palatine fold, two peripheral palatine folds and the choanal fold. The current histological results show the keratinized dorsal lingual surface, in which the keratinized layer extended to cover the papillae. Two types of lingual glands, according to their position, are papillary superficial and deep lingual glands. Papillary or superficial glands open in the interpapillary spaces via narrow openings, while the deep glands are surrounded by well-developed muscles and open via wide openings on the dorsal lingual surface. An entoglossal cartilaginous structure of hyaline cartilage was found in the mid- and hindtongue, with numerous chondrocytes lodged within the lacunae. Our results conclude that the oral cavity of the herbivorous Egyptian tortoise was adapted to the dietary and vigorous demands of the Egyptian fauna.     

Morphology of the tongue and laryngeal entrance in the Common pheasant (Phasianus colchicus); a light and scanning electron microscopic study

The present work was carried out to describe morphological features of the tongue and laryngeal entrance of the Common pheasantPhasianus colchicus, using light and scanning electron microscopy. The lingual apex was taper-shaped with a shallow median sulcus. A V-shaped papillary crest with 15–20 caudally directed conical papillae was located between the radix and corpus linguae. The second row of papillae consisting of three caudolaterally directed conical papillae was arranged caudal to the main papillary crest. The mons laryngealis was equipped caudally with a double-layer of large conical papillae as pharyngeal crest, and few small conical papillae were seen around the glottis. Scanning electron microscope (SEM) observation showed that the apex linguae and corpus were covered with compact filiform papillae, while the radix linguae were free of papillae. Numerous openings of salivary gland can be seen on the radix linguae and mons laryngealis at higher magnification. On histological sections, all parts of the tongue and mons laryngealis were covered with a keratinised stratified squamous epithelium. The keratinised layer became thinner rostro-caudally. The simple alveolar salivary glands were distributed in the submucosa from the apex linguae to the radix linguae as well as the mons laryngealis. PAS staining revealed mucin-secreting activity of this glands. According to the findings, although the tongue and laryngeal entrance of the Common pheasant is characteristics of a galliform bird, it has some features similar to passeriformes and falconiformes.     

Gross Anatomical Features of the Gastrointestinal Tract (GIT) of Blue and Yellow Macaws (Ara ararauna) – Oral Cavity and Pharynx

Morphological studies of the gastrointestinal tract (GIT) of blue and yellow macaws (Ara ararauna) are scarce. Therefore, this study aims to describe the macaw's oropharyngeal cavity in order to supply the deficiency of anatomical data and as part of a broad study of the GIT of these birds. Two male and one female adult blue and yellow macaws were anatomically dissected to expose the oropharynx. The macaw oropharynx was ‘V‐shaped’ and flattened laterally being composed of maxillary and mandibular rhamphotheca of the beak. The tongue, lingual frenulum and laryngeal mound (containing ‘spindle‐shaped’ glottis and prominent mucosal papillae) formed the floor of the oropharynx. The roof revealed two distinct regions separated by a ‘step‐like depression’, whereas in the floor, the mandibular rhamphotheca was separated from the oral cavity mucosa by a large vestibulum enclosing the lingual frenulum. The palate was hard without any signs of rugae nor palatine raphe. A smooth ridge extended caudally from the choana to the common opening of the Eustachian tubes. This study, in addition to confirming the basic features of the oropharynx previously described for birds in general, provided new, unreported morphological data, some of which may be important when studying nutrition and health of these birds.     

Morphological features of the Egyptian Ossimi sheep tongue: New scanning electron microscopic insights into its papillary system adaptations to Egyptian ecological conditions

The current study aims to illustrate the gross and scanning electron microscopic characterizations and ultrastructural adaptation of the lingual papillary system of Egyptian Ossimi sheep to Egyptian ecological conditions. The tongue had three regions: the apex (with a slightly bifurcated tip), the body (subdivided into rostral and caudal parts) and the root (subdivided into rostral papillary and caudal non-papillary parts). Torus linguae had two parts: the triangular rostral part (the caudal part of the body) and the quadrilateral wide part (the rostral part of the root). The lingual papillary system had mechanical (filiform, conical and lentiform) and gustatory (fungiform and circumvallate) types. Filiform papillae were heavily scattered on the dorsal surface of the apex, the rostral part of the body and the ventral surface of the papillary region of the tip. Filiform papillae had five subtypes (ventral and dorsal processed, triangular, leaf-like and triangular-processed papillae), while the conical papillae had three subtypes: two lingual (small, large) and one paralingual (elongated pointed), and the fungiform had two subtypes: the high-density ovoid (on the ventral surface of the tip) and round papillae (on the dorsal surface) that possessed a high number of taste pores, not previously described. They ranged from 5 to 10 for ovoid and 25 to 25 for round papillae. Each circumvallate papilla had an ovoid bulb (with 2–5 taste pores) encircled by an annular groove and two pads (i.e. not described previously). The papillary system's regional divergence was specialized for their harsh and semi-harsh diet.     

Scanning Electron Microscopic Study of the Lingual Papillae in the Arctic Fox (Alopex lagopus L., 1758)

This study aims to show the distribution and the three-dimensional structure of the lingual papillae in the arctic fox. The macro- and microscopic structure of the tongue and its lingual papillae was studied in 11 adult arctic foxes. Two types of mechanical papillae were distinguished on the dorsal surface of the tongue – filiform papillae and conical papillae. The gustatory papillae in the arctic fox are represented by fungiform, vallate and foliate papillae. The keratinized filiform papillae on the anterior part of tongue are composed of one big posterior process accompanied by 10–12 secondary anterior processes. The number of anterior processes of filiform papillae undergo a complete reduction within the area between the posterior part of the body of the tongue and area of the vallate papillae. The conical papillae cover the whole dorsal surface of the root of the tongue, including the lateral parts surrounding the area of the vallate papillae and the posterior part of the root. The size of the conical papillae increases towards the root of the tongue but their density decreases. In the arctic fox, there are three pairs of vallate papillae distributed on the plan of a triangle. The diameter of vallate papillae in each successive pair is bigger. The wall surrounding the body of the vallate papilla and its gustatory trench is composed of six to eight conical papillae joined at various degree. The foliate papillae on both margins of the tongue consist of seven to nine laminae.     

Morphological Study of the Persian Leopard (Panthera pardus saxicolor) Tongue

This study described the morphological features of the Persian leopard (Panthera pardus saxicolor) tongue using light and scanning electron microscopy techniques. The keratinized filiform papillae were distributed all over the entire dorsal surface of the tongue and contained small processes. They were changed into a cylindrical shape in the body and conical shape in the root. The fungiform papillae were found on the apex and margin of the tongue. Few taste pores were observed on the dorsal surface of each papilla. The foliate papillae on the margins of the tongue were composed of several laminae and epithelial fissures. Taste buds were not seen within the non‐keratinized epithelium. The vallate papillae were six in total and arranged in a “V” shape just rostral to the root. Each papilla was surrounded by a groove and pad. Taste buds were seen within their lateral walls. Lyssa was visible on the ventral surface of the tongue tip and was found as cartilaginous tissue surrounded by thin connective tissue fibres. The core of the tongue was composed of lingual glands, skeletal muscle and connective tissue. These glands were confined to the posterior portion of the tongue and were composed of many serous cells and a few mucous cells. The results of this study contributed to the knowledge of the morphological characteristics of the tongue of wild mammals and provided data for the comparison with other mammals.     

Tongue Papillae in Goat: a Scanning Electron-Microscopic Study

The tongue papillae of 6-9-month-old Jamunapari goats were studied by scanning electron-microscopy. The conical-shaped filiform papillae had 3–6 pointed projections and 6–8 secondary papillae at the free tip and the base of the dorsal surface of the tongue, respectively. The convex surfaced fungiform papillae were raised above the lingual mucosa. The vallate papilla was characterized by a papillary groove and an annular pad. The large conical papilla had a round base and a blunt tip without any projection. Two types of lenticular papillae could be distinguished. The irregular surface of all types of papillae revealed microplicae in the form of microridges and micropits. The fungiform papilla was studded with microvilli. The taste pores were oriented on the dorso-lateral surface of the vallate papilla.     

Scanning electron microscopy study of the lingual papillae in the European mole (Talpa europea, L., Talpidae)

The tongue in the adult European mole (Talpa europea L.) was examined by scanning electron microscope. The elongated tongue with a rounded apex is about 12-13 mm in length and 3-4 mm in width. On the apex the shallow median groove is present. On the dorsal surface of the lingual mucosa two types of mechanical papillae and two types of gustatory papillae were observed. Mechanical papillae are represented by numerous filiform papillae with a single process, covering the whole surface of the apex and body of the tongue, and massive conical papillae, found on the root of the tongue. The structure and density of filiform papillae varies in the anterior and posterior part of the tongue. A unique trait of the tongue in the European mole is the occurrence on the apex of the tongue of a single row of conical papillae. Gustatory papillae are represented by numerous fungiform papillae and one pair of vallate papillae. Dome-shaped fungiform papillae in the anterior part of the tongue are arranged linearly along both margins of the tongue, whereas in the posterior part of the body of the tongue flat fungiform papillae are distributed evenly among filiform papillae. Oval vallate papillae are surrounded by a continuous furrow and a single pad. In the posterior part of the root behind conical papillae the surface of the mucosa is flat with numerous orifices of lingual papillae located there. Observations on the distribution and structure of gustatory papillae in the common mole did not show the existence of special traits, differing them from those in terrestrial insectivores. The comparison of the morphology of the tongue, the distribution and structure of the lingual papillae in the European mole with those in the other species of Insectivores, indicated of a general similarity of features within the family Talpidae.     

Resection of the incisive bone and rostral maxillae for removal of an ossifying fibroma in an 18‐year‐old Warmblood gelding

A 510 kg, 18‐year‐old Warmblood gelding used for high level dressage was presented with a 6 week history of a growing mass at the rostral aspect of the incisive bone. Radiographic examination of the maxillae showed an osteolytic lesion between the left maxillary central and intermediate teeth spreading caudally into the hard palate. Biopsy of the mass was consistent with an aggressive oral fibrosarcoma. Diagnostic work‐up ruled out metastatic lesions. An amputation of the incisive bone and part of the rostral maxillae was performed with the intent of removing the mass in healthy margins. However, the neoplastic tissue extended to the rostral aspect of the ventral nasal conchae and a resection in healthy margins was not performed to avoid surgical complications due to communication with the nasal conchae. After surgery, the horse's appetite and food uptake were not impaired and cosmetic appearance was excellent. Active drains were used in order to prevent any submucosal collection of fluids. Histopathological examination of the surgical margins of the removed maxillae confirmed the presence of tumoural tissue. Even though excision of the tumour was not complete, no macroscopic local recurrence was reported post operatively at 36 months' follow‐up. Based on histological re‐evaluation of the removed tissue and the absence of recurrence a definitive diagnosis of ossifying fibroma was made.     

Gross morphological and histological features of larynx, trachea and syrinx in Japanese quail

This study aimed at observing gross morphological and histological characteristics of the larynx, trachea and syrinx in Coturnix coturnix japonicum (Japanese quail). Sixteen mature quails were divided into two groups. Eight animals were stained with 0.1% methylene blue for 15 min, followed by 50% and 70% ethyl alcohol solution for gross morphological examination. For the observation of histological characteristics the larynx, trachea and syrinx were fixed in 10% formaldehyde and embedded in paraffin. Six-micron sections were stained with haematoxylin and eosin. There were three rows of papillae which were located oral (one row) and aboral (two rows) aspects of the mound. The cricoid cartilage was triangular in shape. Only the inlet of the larynx was covered by the olfactory mucosa whereas the rest was covered by the respiratory mucosa. There were 83-91 tracheal rings which were gradually narrowed from the cranial to the caudal direction. No overlapping occurred between the rings. The last few tracheal rings did not fuse dorsally and formed the tympanium. The pessulus possessed connection with the last tracheal ring and the first bronchial ring. Moreover, it was like a semiprism in shape at the region of bifurcation being vertical in direction. The syrinx was formed by the paired, C-shaped and incomplete bronchial syringeal cartilages. The mucosa of the syrinx was lined with a pseudo-stratified layer of prism-shaped epithelium. There were nine or 14 C-shaped cartilaginous primary bronchi.     

Morphological Characteristics of the Vallate Papillae of the One‐Humped Camel (Camelus dromedarius)

In this study, the morphology of the vallate papillae of camel was investigated using gross, light and scanning electron microscopy as well as immunohistochemistry. Vallate papillae were arranged along an identical line on each side of the lingual torus and revealed remarkable individual differences. However, each papilla – round or flat, small or large, single or paired – was surrounded by a prominent groove and an annular pad. Based on our findings, postnatal development and formation of new papillae occur in camel. Microscopically, taste buds were constantly observed along the medial wall epithelium, and in the papillary wall epithelium on both sides of the secondary groove apparently separating the vallate papillae. In addition, an aggregation of taste buds was occasionally observed at the bottom of the lateral wall epithelium. Using SEM, we observed several pits and microplicae on the surface of papillae as well as distinct taste pores on the peripheral parts of the dorsal surface. We demonstrated immunoreactivity of α‐gustducin only in mature taste buds. We conclude that the morphological features and microstructure of vallate papillae are a characteristic feature in camel compared to other ruminants. These features might have evolved to assist the camel in the manipulation and tasting of thin organic stiff plants that grow in its environment and therefore might have related to the feeding habits of the animal.     

The distrubution of Herbst corpuscles in the beak of the domestic fowl

Histological examination of a series of sections of beaks of domestic fowl has demonstrated the presence of Herbst corpuscles of two size ranges in the corium of the rhinotheca and hard palate respectively. These are distributed over the lateral surface of the body of the premaxillary bones in a broad band and beneath the lateral ridges of the hard palate. They extended as far anterior as the anterior apex of the premaxillary bones.     

Ultrastructure of Lingual Papillae in Common Chimpanzee (Pan troglodytes) Foetus,Newborn and Adult Specimens

Among primates, the two recognized species of chimpanzees (common chimpanzee, Pan troglodytes; pygmy chimpanzee, Pan paniscus) are considered to be the most similar to humans. Importantly, in mammals, the food intake behaviour largely determines the tongue morphology, including the type, proportion and distribution of gustatory and non‐gustatory tongue papillae. The lingual papillae form during its development and mature in post‐natal life depending on the different feeding. In this study, we have used scanning electron microscopy to analyse the age‐related changes in the lingual papillae of foetal, newborn and adult P. troglodytes. Four main types of lingual papillae, denominated filiform, fungiform, foliate and vallate, and one subtype of filiform papillae called conical papillae, were found. The main age‐related changes observed in all kinds of papillae were a progressive keratinization and morphological complexity along the lifespan. During the foetal period, there was scarce keratinization, which progressively increases in young animals to adulthood. The number of filiform increased with ageing, and both filiform and fungiform papillae in adult tongues are divided into pseudopapillae. On the other hand, the vallate papillae vary from smooth simple surfaces in foetal tongues to irregular surfaces with grooves and pseudopapillae (microscopic papilla‐shaped formations within the papilla itself) in adults. These results describe for the first time the age‐related variations in the three‐dimensional aspect of lingual papillae of the chimpanzee tongue and provide new data to characterize more precisely these structures in the human closest specie.