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.

Skull variation in different breeds sheep from Balkan countries.

The Balkan Peninsula region has a very diverse agricultural and livestock tradition, and almost every country has its own local breed of sheep. Different breeds of sheep and different breeding traditions, despite the small geographical distance, determine the morphological and morphometric variability among animal breeds. In this study, this morphological diversity among the skulls of sheep breeds of some countries in the Balkan region was examined by the geometric morphometric method. 2D images of 86 sheep skulls from five different countries were analyzed from the dorsal view.Sixteen landmarks were used. The Bardhoka and the Ivesi breed have the broadest distributions of skull shape amongst the sheep breeds. The Ruda sheep is the most morphologically conservative. The sheep from Turkey (Ivesi) and Kosovo (Bardhoka) seem to differ mainly from sheep from other Balkan countries. Bardhoka and Ruda differ most from each other (p < 0.0001). The next biggest differences were between Ivesi and Ruda (p < 0.0011) and between Bardhoka and Sharri sheep (p < 0.0016). The sheep breeds Dubska and Lara e Polisit differ the least from each other. Geometrics morphometric analysis is a useful tool to detect differences in the shape of the skull of different sheep breeds and can therefore be used successfully for taxonomic purposes.

Blood supply to the cranial cavity in the patagonian mara (Dolichotis patagonum).

Rodents are the most numerous order of mammals. The literature presents information on the arterial circle of the brain in capybara, the guinea pig of the family Caviidae and many other not so closely related rodent species. Information on the blood supply to the brain is often incomplete and focuses on one pathway in a broader comparative aspect. The supply of oxygen and nutrients to the brain is very important for its proper functioning. The aim of this study is to describe the pathways supplying blood to the cranial cavity and to describe the arterial circle of the brain in the Patagonian mara. The study was conducted on 46 specimens using two methods. The first of them used a stained solution of the chemo-setting acrylic material. The second one, the colored liquid LBS 3060 latex. The arterial circle of the brain is a heart-shaped structure. It is formed by rostral cerebral arteries, caudal communicating arteries and the basilar artery. Blood supplies the arterial circle of the brain in three ways. First one is the basilar artery, which originates from the vertebral arteries. The second one is the internal carotid artery which joins a branch from the external ophthalmic artery. The third is the internal ophthalmic artery, which branches from the external ophthalmic artery.

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.

Strategies of vascularization of the ethmoid labyrinth in selected even-toed ungulates (Artiodactyla) and carnivores (Carnivora).

The anatomy of the nasal cavity and its structures, as well as other elements building a scaffold for olfactory organs, differs significantly among various groups of mammals. Understanding anatomical conditions of quality of olfaction are being studied worldwide and is a complex problem. Among many studies regarding bone and epithelial structures of turbinates and connected anatomical structures, few studies describe the vascularization of turbinates. Ethmoid turbinates are above all covered in olfactory epithelium containing branched axons that receive olfactory stimuli and as olfactory nerves penetrate the cribriform lamina of the ethmoid bone conveying information from smell receptors to the brain. Differences in vascularization of the cribriform plate and turbinates may add crucial information complementing studies regarding the olfactory organ's bone and soft tissue structures. In the study, we describe the vascularization of the cribriform plate of the ethmoid bone of 54 Artiodactyla and Carnivora.

Arterial circle of the brain in the common wildebeest (Connochaetes taurinus).

The main aim of this study was to analyze the arterial circle of the brain and rostral epidural rete mirabile in specimens of the common wildebeest (Connochaetes taurinus). The arterial circle of the brain is a circulatory anastomosis that supplies blood to particular lobes of the brain and surrounding structures. The study was conducted on male and female adults (n = 12) by bilateral injection of an acetone solution of vinyl superchloride or latex LBS3060, which resulted in a cast of arteries of the head and encephalic base. We describe the exact structure of the arterial circle of the brain and rostral epidural rete mirabile. The shape of the arterial circle of the brain in the common wildebeest is heart-shaped, as in other Bovidae. It is formed by bilateral rostral cerebral arteries, caudal communicating arteries, and the basilar artery, with a general pattern of vessels forming and branching off from the arterial circle of the brain, as described in other ruminants. The rostral cerebral and caudal communicating arteries emerge from an intracranial segment of the internal carotid artery, which in turn arises from vessels of the rostral epidural rete mirabile. This structure, well developed in the examined individuals, has mechanisms underlying selective cooling of the brain, protecting animals from hyperthermia, and affecting body water balance.