Morphological examination of the visual system and orbital region in the red panda (Ailurus fulgens fulgens).

OBJECTIVES: The red panda is currently the only surviving member of the Ailuridae family in the Caniformia suborder. In this study, we provide data on anatomical, morphometric, histological and histochemical examination of the orbital region, eyelids, orbital gland, and eye tunics in two adult males Ailurus fulgens fulgens from the Wroclaw Zoological Garden, Poland. METHODS: The study involved morphometric analysis of the eyeball and selected accessory organs of the eye, along with analysis of the bony orbit, including its morphometry, macroscopic, and microscopic evaluation. Microscopic evaluation encompassed histological and histochemical staining, with the former involving hematoxylin & eosin (H&E), Movat pentachrome, picro-Mallory trichrome, Fontana-Masson, and the latter including PAS, AB pH 1.0, AB pH 2.5; AB pH 2.5/PAS, and HDI. RESULTS: The upper (UE) and lower (LE) eyelids presented well-developed tarsal glands, sebaceous glands, and a characteristic simple alveolar gland (producing a mucous secretion). The palpebral part of the lacrimal gland was present. A single lymphoid follicle was observed only in the upper eyelids. The superficial gland of the third eyelid (SGTE) was a multilobar acinar complex that produces mucous secretion and is contained within the interlobular ducts of numerous aggregates of lymph nodes. The third eyelid (TE) was T-shaped and composed of hyaline tissue, containing CALT. The lacrimal gland (LG) also revealed a multilobar acinar complex that produced mucous secretion, with a single lymphoid follicle. The cornea consisted of 4 layers, as Bowman's membrane was absent. The Vogt palisades composed of 7-10 layers of epithelial cells were demonstrated. The pupil was horizontally ovoid at rest (post-mortem). The sphincter pupil and the dilator pupil were well developed. Macroscopically, the tapetum lucidum appeared as a milky, non-opalescent crescent. Histologically, the choroidal tapetum lucidum cellulosum consisted of 5 to 9 layers of loosely packed oval cells. The retina showed a composition similar to that of terrestrial nocturnal carnivores. CONCLUSIONS: The results of our research indicate that the anatomical features of the eye and orbital region in the red panda share similarities with those described in the Musteloidea clade, as well as the Canidae and Ursidae families.

Topography of cranial foramina and anaesthesia techniques of cranial nerves in selected species of primates (Cebidae, Cercopithecidae, Lemuridae) - part I - osteology.

BACKGROUND: Conductive anaesthesia of the nerves around the head is one of the methods of intraoperative pain relief (under deep anaesthesia but before proceeding with the procedure). Performing this procedure on primates is especially challenging for the veterinarian, due to their cranial anatomy and topography, which has more in common with the human skull than with the skulls of other animals. Knowledge of key bony structures, including cranial foramina, is essential for effective anaesthesia of the cranial nerves. RESULTS: In this study, the differences in the topography of the cranial foramina in eight selected species of primates were examined: Angola colobus (Colobus angolensis), Celebes crested macaque (Macaca nigra), L'Hoest's monkey (Allochrocebus lhoesti), baboon (Papio cynocephalus), buff-bellied capuchin (Sapajus xanthosternos), black-and-white ruffed lemur (Varecia variegata), crowned lemur (Eulemur coronatus), and a ring-tailed lemur (Lemur catta) coming from the Wroclaw Zoological Garden (Poland). The cranial nerves running through the foramina have also been described and their anaesthesia techniques against bone points have been tested to relieve post-operative pain in the area of the head supplied by these nerves. CONCLUSION: The tests carried out show differences in the topography of the cranial foramina, and therefore also differences in the methods of injection, so the results obtained in this study may be useful in veterinary medicine, especially for practising veterinarians.

Gross anatomy of coronary veins of the European bison (Bison bonasus).

BACKGROUND: Although significant efforts have been put into restituting the European bison (Bison bonasus) and increasing its population, it remains a globally endangered species and requires conservation. Protection programs of bison indicate the need for morphological studies of their individual systems, in order to enhance restitution programs and enable appropriate veterinary care. The aim of this study was to investigate the morphology of the coronary veins of the European bison (Bison bonasus). RESULTS: The study was carried out on 78 hearts of European bison of both sexes, aged 5 to 21 years. The subepicardial veins were clearly visible after being filled with dyed synthetic latex (LBS 3060), Plastogen G and Batson's No. 17. In all the studied animals, the great cardiac vein drains into the coronary sinus. The interventricular paraconal branch and the circumflex branch of the great cardiac vein were distinguished. The left marginal vein, which originated in the apical area or halfway along the length of the left ventricular margin, was easily identified in 65 animals (83%). In most animals (51 bison, 65%), the middle cardiac vein drained into the coronary sinus, while in some animals it drained into the right atrium (27 animals, 35%). CONCLUSIONS: Blood from the cardiac walls is drained into the great cardiac vein, the middle cardiac vein, the right coronary veins and numerous small cardiac veins.

Morphology of the extraocular muscles (m. bulbi) in the pre-hatchling and post-hatchling african black ostriches (struthio camelus domesticus L., 1758) (Aves: Struthioniformes).

The aim of the study was to describe the morphology and the development of the extraocular muscles (EOMs) in the pre-hatchling and post-hatchling African black ostrich. The study involved 50 birds aged between 28 days and 3 years. The EOMs were analyzed morphologically with respect to the location and length of the straight and oblique muscles and the third eyelid muscles, the length and breadth of their tendons as well as the distance and shape of the muscle tendon insertions at the corneal limbus. A histological and histometric analysis were also carried out. The greatest increase in the length of the EOMs was noted in groups III-V. A marked increase in the length of the tendons of the dorsal straight muscle was found in groups II and III, in the tendons of the nasal straight muscle in groups IV and V, in the tendons of the dorsal oblique muscle in groups III to V and in the tendons of the ventral oblique muscle in groups IV and V. There was a significant increase in the breadth of the dorsal straight and ventral oblique muscle tendons in groups IV and V and the tendons of the pyramidal muscle in groups III and V. The distance of the distal insertion of the tendon at the corneal limbus increased steadily with age in all the examined groups. The number of fascicles and muscle fibres, their diameter and length in all the studied EOMs were different in the different groups.

The presence of ovarian cysts in a captive Antillean manatee (Trichechus manatus manatus L. 1758).

BACKGROUND: Several pathological changes associated with reproductive systems of marine mammals have been reported in primary literature. However, no such records exist regarding ovarian cysts in the Antillean manatee (Trichechus manatus manatus L. 1758). CASE PRESENTATION: A nulliparous female Antillean manatee, held in captivity at the Wroclaw Zoological Garden, died in April 2015. The animal was 370 cm long from nose to tail and weighed 670 kg. The width of manatee's fluke was 80 cm. The post-mortem examination of the reproductive system showed the numerous pathological cysts on the external surface of the left and the right ovaries. Morphologically, the cysts had varying diameters and were attached to the ovaries by stalks. Some of the cysts were thin-walled and contained fluid, while several others were solid or contained a semi-solid mass. The structure of the ovaries displayed features of the polycystic ovary syndrome (PCOS). The cysts also exhibited positivity with cytokeratin and vimentin. There were no pathological changes within the uterus, uterine tube and vagina. CONCLUSION: Although we were unable to definitively determine the exact source of the ovarian cysts in the studied manatee, we found that one of the causes may be age-related. Our study also revealed that ovarian cysts in the Antillean manatee form both types of corpora lutea (CL).

The morphology of the adrenal gland in the European bison (Bison bonasus).

BACKGROUND: The anatomy of the adrenal glands has been widely studied in many species of domestic and wild mammals. However, there are no available literature reports describing the morphology and morphometry of the adrenal glands of the European bison (Bison bonasus). RESULTS: The study was conducted on 97 European bison of both sexes. The growth of the adrenal glands corresponded to the growth of the whole body, with the largest increase in size occurring in the first 2 years of the animal's life, followed by a slower increase in size until the animal was 5-7 years old. There were no statistically significant differences between ipsilateral adrenal glands of males and females with respect to age. There was no statistically significant difference in weight between the left and the right adrenal gland. However, there was a difference in the length, width and thickness of the two glands. Reference intervals for adrenal gland size and weight were computed separately for two bison age groups (up to 2 years of age and older than two years). The adrenal gland consisted of a cortex and a medulla. The connective-tissue capsule contained two layers. It had a fibrous structure and abundant adipose tissue. The cortex was divided into three zones. The zona glomerulosa contained cells arranged in bundles and curves. Numerous apoptotic cells were observed among regular cells in the zona reticularis. There were vacuoles in the cells of both zona fasciculata and zona reticularis, which formed a foamy cytoplasm. The adrenal medulla was composed of large, dark cells with a highly basophilic cytoplasm in the superficial region and of smaller, lighter cells in deeper layers. Sinusoidal vessels were located in the central part of the medulla. CONCLUSIONS: The left adrenal gland was significantly longer, narrower and thinner than the right one. There were no significant differences in the structure of the adrenal medulla and cortex of the European bison compared to other species of domestic and wild mammals. There was a thick layer of adipose cells at numerous locations in the adrenal capsule of the bison.

Functional Morphology of the Upper and Lower Eyelids, Third Eyelid, Lacrimal Gland and Superficial Gland of the Third Eyelid in the Red Kangaroo (Macropus rufus).

A study concerning the upper (UE) and lower (LE) eyelids, lacrimal gland (LG), superficial gland of the third eyelid (SGTE) and third eyelid (TE) was conducted on 4 sexually mature red kangaroos (2 males and 2 females). Gross anatomical, histological, histometrical, histochemical and ultrastructural (TEM) components were compared. Tissue sections were stained with haematoxylin and eosin, azan-trichrome, van Gieson, Masson-Goldner trichrome, methyl green-pyronin Y, periodic acid-Schiff, alcian blue pH 2.5, aldehyde fuchsin and Hale's dialysed iron. The location of the LG, SGTE, TE, UE and LE was similar to that of other mammals. Organized lymphoid follicles were also found in the LE. The TE resembled the letter T and was composed of cartilage (hyaline tissue). The LG was relatively larger than the SGTE. The LG and SGTE were multilobar tubuloacinar glands. The LG had more plasma cells than the SGTE. The SGTE and LG secretions were mucoserous in composition. The TEM study showed that the secretory cells of the LG and SGTE have a similar ultrastructural appearance. Two types of secretory vesicles were detected in the cytoplasm in acini and one type of secretory vesicle was found in the tubules of these glands.

Histological, histochemical and ultrastructural studies on Harderian and lacrimal glands of the Capercaillie (Tetrao urogallus major L.).

This study describes the macroscopic anatomy and the microscopic and ultrastructural features of the Harderian gland and lacrimal gland of the Capercaillies. It was conducted both on adult male and female Capercaillies. Tissue sections were stained with hematoxylin and eosin, azan trichrome, modified Mallory's trichrome, methyl green-pyronin Y, periodic acid-Schiff, alcian blue pH 2.5, aldehyde fuchsin and Hale's dialysed iron. The morphometric study of the Harderian and lacrimal glands indicated that they are both larger in male than in female Capercaillies. The histological analysis showed that the HG has a multilobar tubulo-alveolar structure with numerous lymphocytes and plasma cells. The LG has a multilobar tubulo-acinar structure without lymphocytes and plasma cells. The periodic acid-Schiff staining and alcian blue pH 2.5 staining demonstrated a mild positive reaction in the epithelial cells of the Harderian gland and weak positive reaction in the lacrimal gland. The HDI staining detected the presence of carboxylated acid mucopolysaccharides in the Harderian and lacrimal glands. Transmission electron microscopy revealed the presence of two types of secretory vesicles in the cytoplasm of both studied glands. It also showed that lipid droplets and glycogen granules were more abundant in the Harderian gland than in the lacrimal gland of this species.

Light and electron microscopic studies of the Harderian gland in Bilgorajska goose (Anser anser).

The Harderian gland (HG) in birds is the dominant orbital gland, which plays an important role in immunological response. Tissue sections taken from adult females of Bilgorajska goose were stained with hematoxylin-eosin, Azan, PAS, AB pH 2.5, AF and HDI. Based on the histological structure the HG in Bilgorajska geese had compound tubular structure with multiple lobules and two types of epithelial cells lining the tubules. Epithelial cells in the central part of the lobes were dark in color and contained serous fluid, while in the deeper layers, epithelial cells were lightly coloured and contained mucous fluid. Histochemical studies showed the presence of neutral mucopolysaccharides and carboxylated acid mucopolysaccharides in the secretory cells. The small number of single plasma cells were present in HDI staining below the basement membrane of the secondary and primary ducts, near the crypts of the main duct. TEM study demonstrated that plasma cells had a large nucleus with condensed heterochromatin and were rich in rough endoplasmic reticulum. The knowledge of gland's structure, and above all an analysis of the immune system components may affect clinical practice and properly conducted immunization of birds.

The organ of vision morphology of the southern two-toed sloth (Choloepus didactylus Linnaeus, 1758; Pilosa, Choloepodidae).

The Choloepus didactylus is a species belonging to the Choloepodidae family of the Folivora suborder. This study concerns the anatomical, morphometrical, histological and histochemical examination of the eye tunics, eyelids and orbital glands in the three adult Choloepus didactylus coming from the Wroclaw Zoological Garden. The cornea consists of four layers since Bowman's membrane was absent. The presence of palisades of Vogt formed from 14/15 to 20/21 layers of epithelial cells was demonstrated. Macroscopically, the tapetum lucidum was not identified, while degenerative choroidal tapetum lucidum cellulosum was found microscopically. The ciliary muscle was found with our histological approach. The pupil was round in shape (post-mortem). The presence of tarsal glands has not been demonstrated in both eyelids. The conjunctiva-associated lymphoid tissue (CALT) has been shown in the upper and lower eyelids. The superficial gland of the third eyelid produced a seromucous secretion. The third eyelid was shaped like a curved arch and composed of hyaline cartilage. The deep gland of the third eyelid was big and multilobar acinar simple with serous character. The lacrimal gland produced mucous secretion. The results of our research indicate that the features of the eye anatomy in the southern two-toed sloth (C. didactylus) are also typical of the Folivora suborder and have common features and differences with Vermilingua.

Morphological adaptation of the tongue of okapi (Okapia johnstoni Artiodactyla, Giraffidae)-Anatomy, histology, and ultrastructure.

The aim of this study was to describe the morphology of the tongue of the okapi, and to compare the results with other ruminants including browsers, intermediates and grazers. The material was collected post-mortem from two animals from a Zoological Garden. The structure of the okapi tongue, focusing of the shape of the tongue, lingual surface, its papillae and lingual glands, was examined using gross morphology, light and polarized microscopy, and by scanning electron microscopy. The okapi tongue was characterized by dark pigmentation on the lingual dorsum (except lingual torus) and on the whole ventral surface. Two types of filiform papillae were observed, with additional, even 6-8 projections at their base. The round fungiform papillae were present at a higher density, up to 16/cm2, on the ventro-lateral area of the lingual apex. Round and elongate vallate papillae were arranged in two parallel lines between the body and root of the tongue. Numerous taste buds were detected within the epithelium of their vallum, while fungiform papillae had sparse taste buds. A lack of foliate papillae was noted. Very small conical papillae, some lenticular in shape, were present on the lingual torus. Thick collagen type I fibers were dominant over collagen type III fibers in the connective tissue of the lingual papillae. The mucous acini units were dominant among lingual glands, indicating that the secretion of okapi lingual glands was mostly mucous. In many aspects, the tongue of okapi resembles the tongue of other ruminants. The specific lingual shape and lingual surface, together with the lingual glands, support the processing of plant food, such as young and soft leaves. Although okapi tongue is characterized by smaller conical papillae compared to other ruminants, its high number of vallate papillae is similar that found in other browsers, intermediate and grazers. Thus the number of gustatory papillae rather indicates that this feature is not related to the type of feeding.

Biological Significance of the Komodo Dragon's Tail (Varanus komodoensis, Varanidae).

The Komodo dragon is a unique reptile with an elongated tail that exhibits hitherto unknown adaptations and functions. This tail, composed of 60-86 vertebrae, serves diverse ecological and physiological roles. In juveniles, it is essential for an arboreal lifestyle and balance, while in adults, it functions as a tool for defense and offensive actions. It possesses characteristic haemal arches and a dorsal keel, along with well-developed muscles which enable precise tail control, influencing the Komodo dragon's maneuverability and directional changes. The tail stores adipose tissue, providing Komodo dragons with the ability to regulate body temperature and independence from other seasonal variations. The tail adipose tissue impacts numerous biochemical processes and may play a crucial role in the animals' metabolic strategies and reproductive capabilities. Its functions include providing essential mineral compounds for the organism, such as calcium, phosphorus, magnesium, iron, and zinc. Analysing the biochemical composition of tail fat is crucial for understanding the health of Komodo dragons.

Lingual Ultrastructural and Histochemical Study in the Patagonian Mara (Rodentia: Caviidae, Dolichotis patagonum) in Relation to Other Hystricomorphs.

The study describes the ultrastructure of the tongue in the Patagonian mara (Dolichotis patagonum) using light and scanning electron microscopy. Histochemical methods were used for evaluation of lingual salivary glands. The tongue is divided into a small and rounded apex, a narrow corpus, and a significantly wider radix, with a well-developed lingual prominence. The tip of the apex is free of papillae. The caudal part of the apex and the corpus are covered by filiform papillae. Round fungiform papillae are scattered among them. Papillae on the narrow stalk are conical. The radix contains caudally bent papillae forming wide flat prominences, slender, hook shaped filiform papillae, foliate papillae, and two oval vallate papillae. Taste buds were found on the lateral sides of the foliate and vallate papillae. Purely serous salivary glands are beneath the vallate and foliate papillae. Serous acini and mucous tubules are in the lingual radix. The Patagonian mara is the only hystricomorph rodent with described hyaline cartilage strengthening the lingual radix. Some typical signs of adaptation to herbivorous diet were found. The structure of the tongue is adapted to grass-feeding, as grasses form the main component of their diet.

Morphometry and topography of the coronary ostia in the dog.

Introduction: The purpose of this study was to perform a morphometric examination of the coronary ostia, including their location in the area of the aortic sinuses, and to describe variations in ostia structure in the domestic dog. Material and Methods: The study was conducted on the hearts of 91 pedigree dogs of both sexes, aged 1 to 18 years (median 9 years), with a body weight from 1.2 to 65 kg (median 20.7 kg). Morphometric examinations of the coronary ostia were performed in the studied individuals, and the location of the structures in relation to the intercommissural lines was determined. Results: Three types of location of the coronary ostia were distinguished, i.e. below the intercommissural line (type I), on the intercommissural line (type II), and above the intercommissural line (type III). In the studied dogs, the most common location of the ostia was type I - found in the left coronary artery of 74/91 dogs (81%) and in the right coronary artery of 42/91 dogs (46%). Morphological variations were shown in 36/91 dogs (40%) in the structure of the coronary ostia, including the presence of accessory ostia. The most common variation was the presence of an accessory ostium near the ostium of the right coronary artery, which was found in 28/91 dogs (31%). Conclusion: The results may be useful in developing standards for procedures to replace the whole or part of the aortic valve and repair the coronary artery.

Anatomical, Histological and Histochemical Observations of the Eyelids and Orbital Glands in the Lowland Tapir (Tapirus terrestris Linnaeus, 1785) (Perissodactyla: Ceratomorpha).

The lowland tapir is one of four species belonging to the Tapiridae family of the Ceratomorpha suborder, similar to Rhinocerotidae. This study describes anatomy with morphometry, histology (hematoxylin and eosin, Masson-Goldner trichrome, Movat pentachrome, mucicarmine, picro-Mallory trichrome) and histochemistry (PAS, AB pH 1.0, AB pH 2.5; AB pH2.5/PAS and HDI) of the upper and lower eyelids, and superficial gland of the third eyelid with the third eyelid, deep gland of the third eyelid, and lacrimal gland. The aim of the work is to show the features of the above-mentioned structures typical only for Tapiridae, as well as to show the presence of similarities and differences between the families forming the order Perissodactyla. The eyelashes on the upper eyelid were long, while those of the lower eyelid were short and much less prominent. In the upper and lower eyelid sebaceous glands, a characteristic simple alveolar gland producing a mucus-like secretion and poorly developed tarsal glands were observed. The marginal zone of the posterior surface of the eyelids was covered by stratified columnar epithelium with 18-21 layers of nucleated cells, while the bulbar zone of these surfaces was covered by cubic multilayer epithelium with 6-11 non-keratinized layers of cells and with sparse goblet cells. In only lower eyelids, numerous lymphoid nodules, diffuse lymphocytes and high endothelial venules were observed. The superficial gland was an acinar complex which secreted mucous and contained plasma cells within the interlobular and interlobular connective tissue. The upper and lower branches of the third eyelid were the shape of a bent "caudal fin" and were composed of hyaline cartilage, and they contained conjunctiva associated lymphoid tissue (CALT). The deep gland was also an acinar complex producing a serous character and having numerous diffuse lymphocytes. The lacrimal gland was an acinar complex producing seromucous secretions and had numerous plasma cells located in the glandular interstitium. The results of our research indicate that the features of the anatomy of the eyelids and orbital region in the lowland tapir are also typical of the family Tapiridae, but also have features common to the families Equidae and Rhinocerotidae. We confirm the presence of poorly developed tarsal glands in both eyelids as well as presence of a palpebral part of the lacrimal gland in the upper eyelid, which is typical only to Tapirus terrestris.

Comparative Histology and Histochemistry of the Parotid Gland and Mandibular Gland in the Lowland Tapir (Tapirus terrestris Perissodactyla) and Aardvark (Orycteropus afer Tubulidentata).

In terrestrial mammals, the parotid and mandibular glands secrete different types of saliva into the oral cavity. Both glands were obtained from two female lowland tapirs (Tapirus terrestris) and one female aardvark (Orycteropus afer) from the Wroclaw Zoological Garden (Poland) and examined by light microscopy (hematoxylin and eosin, mucicarmine, periodic acid-Schiff, Alcian blue pH 1.0, Alcian blue pH 2.5, Alcian blue pH 2.5/PAS, and Hale's dialysed iron). Both the parotid glands observed in the lowland tapir and aardvark were compound alveolar serous secretory units, and in both species, the secretion was composed of neutral and acidic mucopolysaccharides (sialo and sulfated mucins). However, in both the lowland tapir and aardvark, a histological examination found the stroma of the mandibular gland was divided into very large lobes by poorly marked connective tissue. While many interlobar and striated ducts were found in the aardvark, very few were found in the lowland tapir. The mandibular gland was a branched tubular (mucous secretion) type in the lowland tapir, but it was a branched tubuloalveolar (mucous-serous) type in the aardvark. In all tested glands, the secretion was composed of neutral mucopolysaccharides, acid-sulfated mucosubstances, and sialomucins.

Comparative Study of Lingual Papillae, Lingual Glands and Lyssa of the Tongue of Selected Wild Felids (Carnivora, Felidae) in Biological Aspects.

Although much attention has been paid in the literature to the morphology of the tongue in various animal species, including some Felidae, it has not yet been described in detail in the vulnerable Neofelis nebulosa and Panthera leo bleyenberghi and the last concern Lynx lynx and Otocolobus manul. Therefore, the present study aimed to characterize the features of the tongue surface, lingual glands and lyssa in the above-mentioned four selected wild species of the Pantherinae and Felinae subfamilies. Macroscopic, histological, histochemical and ultrastructural analyzes were used in the present work. Comparative analyzes of the dorsal tongue surface showed the presence of mechanical lingual papillae on five subtypes of filiform papillae on the apex and body and conical papillae on the root of the tongue. Gustatory papillae in the four analyzed species were fungiform papillae and various numbers of vallate papillae. Foliate papillae were absent in P. leo bleyenberghi and L. lynx, while delicate smooth folds, which were separated by parallel grooves but without taste buds, were present in N. nebulosa. The vallate and foliate papillae were accompanied by lingual glands, which produced a serous secretion, whereas the mixed lingual glands of the lingual root were with a predominance of mucus secretions comparable to four captive Felidae species. In the median plane on the ventral surface of the apex under its epithelium and within the muscle fibers, the lyssa was also observed to a varying degree, with the least developed, and thought about the size of the entire tongue, was in P. leo bleyenberghi. The lyssa structure in the four species was dominated by adipose tissue. The obtained results contribute knowledge concerning the functional anatomy of the tongue in four selected Felidae species, especially in terms of comparative anatomy.

Macroanatomical, Histological and Microtomographic Study of the Teeth of the Komodo Dragon (Varanus komodoensis)-Adaptation to Hunting.

The present study aimed to characterize the macrostructure and microstructure of the mandibular teeth of the Komodo dragon (Varanus komodoensis) and the methods it uses to obtain food. Examinations were performed using a stereoscopic microscope, autofluorescence method, histological method and computed microtomography. A detailed macro- and micro-structural description of V. komodoensis mandibular teeth were made. The mandibular teeth are laterally flattened along their entire length and the dental crown is hooked caudally. The part of the nasal margin of the tooth crown is irregular, while the caudal margin of the tooth is characteristically serrated, except for the tooth base area. There are longitudinal grooves on the lingual and vestibular surfaces up to the lower third of the tooth height. The mandibular tooth is surrounded by a cuff made of the oral mucosa, containing the opening of the venom gland. In the histological structure of the tooth, the enamel covering the tooth crown and the dentin under the enamel are distinguished. The inside of the tooth, except its basal part, is filled with the tooth chamber, while the inside of the lower part of the tooth is filled with plicidentine, which corresponds to external furrows on the enamel. The plicidentine arrangement resembles a honeycomb. A small amount of dentine folds reach up to the tooth apex. Characteristic features of the structure of the mandibular teeth in V. komodoensis may indicate their significant role, in addition to the venom glands, in obtaining food in the natural environment of this species.

Functional Anatomy of the Thoracic Limb of the Komodo Dragon (Varanus komodoensis).

Since the Komodo dragon has been included on The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, it is crucial to know in detail its biology as there is a limited availability of research material on these animals-mainly those who died in zoos or whose remains were found in the wild. Anatomy is essential for understanding physiology, identification of diseases, adaptations in the environment, and behavior. In this dissection study, the relationship of individual anatomical structures was analyzed, the anatomy of the active and passive movement system of the thoracic limb was described, photographs were taken, and a radiographic examination was conducted. This species has its own differences, even within closely related lizard species. Varanus komodoensis possesses triceps muscles with three heads, and the wrist is extended with additional bones for greater flexibility of the hand. The muscles of the forelimb are analogous to the hind limb; however, they differ in the mass of individual muscles, especially those predisposed to perform the most important antigravity and locomotive functions.

Comparative Histology of the Cornea and Palisades of Vogt in the Different Wild Ruminants (Bovidae, Camelidae, Cervidae, Giraffidae, Tragulidae).

In the study, we data concerning the histological and morphometrical examination of the cornea and palisades of Vogt in the different species of ruminants from the families Bovidae, Camelidae, Cervidae, Giraffidae and Tragulidae, coming from the Warsaw Zoological Garden, the Wroclaw Zoological Garden and the Division of Animal Anatomy. The following ruminant species were investigated: common wildebeest, Kirk's dik-dik, Natal red duiker, scimitar oryx, sitatunga, Philippine spotted deer, Père David's deer, moose, reindeer, reticulated giraffe, okapi, Balabac mouse-deer and alpaca. The cornea of ruminant species such as the common wildebeest, Kirk's dik-dik, Natal red duiker, scimitar oryx, reindeer and Balabac mouse-deer consisted of four layers (not found in the Bowman's layer): the anterior corneal epithelium, the proper substance of the cornea, the posterior limiting membrane (Descemet's membrane) and the posterior corneal epithelium (endothelium). The anterior corneal epithelium was composed of a multilayer keratinizing squamous epithelium, which was characterized in the studied ruminants with a variable number of cell layers but also with a different thickness both in the central epithelium part and in the peripheral part. Moreover, the proper substance of cornea was thinnest in Balabac mouse-deer, Kirk's dik-dik, Natal red duiker, scimitar oryx, Philippine spotted deer, alpaca, reindeer and sitatunga and was thickest in the reticulated giraffe. The thickest Descemet's membrane was observed in the Père David's deer. The corneal limbus is characterized by a large number of pigment cell clusters in Kirk's dik-dik, scimitar oryx, moose, Balabac mouse-deer and alpaca. In the common wildebeest, Père David's deer, moose, reticulated giraffe, okapi and alpaca, the palisades of Vogt were marked in the form of a crypt-like structure. The corneal limbus epithelium in the examined ruminants was characterized by a variable number of cell layers but also a variable number of melanocytes located in different layers of this epithelium. The detailed knowledge of the corneal structure of domestic and wild animals can contribute to the even better development of methods for treating eye diseases in veterinary medicine.