The developmental architecture of the crop of quail embryos (Coturnix coturnix): Morphometric, light and scanning electron microscopy

The present study focused on the histogenesis of the crop in quail embryos. The developmental sequence was recorded from day 10 of incubation to the hatching day (17th day) by gross anatomy, morphometric analysis and by using light and scanning electron microscope (SEM). Grossly, the crop was distinguished as an enlarged pouch of the cervical oesophagus on the 12th day of incubation. Histologically, the development of the crop began on the 10th day of incubation. The muscularis mucosae was observed as a small, thin layer of myoblast cells on the 10th day, then it appeared as longitudinally arranged smooth muscle fibres with progression of the developmental age till hatching day. The submucosal layer was also observed on the 10th day, while the lamina propria, muscular layer (inner circular and outer longitudinal layers of smooth muscle fibre) and glandular primordia were detected on the 12th day. The epithelial cells of crop revealed affinity for PAS stain and AB-PAS on the 10th day of incubation till the 17th day, while the affinity for AB stain appeared on the 14th day of incubation. Additionally, the glandular cells showed the positive for AB, PAS and AB-PAS on the 12th day of incubation. SEM sections showed variable sizes of the openings of the oesophageal glands. In conclusion, the present study provided a detailed overview of the histogenesis of the crop in quail embryos.

Age-related morphological and ultrastructural changes in the palate and pharyngeal masticatory apparatus of grass carp (Ctenopharyngodon idella) juveniles

Grass carp (Ctenopharyngodon idella or C. idella) is a Cyprinid fish frequently utilized for aquaculture, medical, and research purposes. In C. idella, the palate is followed by a well-developed pharyngeal masticatory apparatus. The latter consists of an upper chewing pad superimposing a paired set of teeth. The present study investigated morphological, morphometric, histochemical, and surface ultrastructural changes involving these structures in C. idella juveniles at three different timepoints namely 35 mm total length (TL; 59 days posthatching (dph); fry-fingerling transition), 70 mm TL (90 dph; fingerling), and 210 mm TL ( 365 dph: yearling). The palatal epithelium revealed a constant number of taste buds. However, the height and width of these buds revealed an age-dependent increase. The number of palatal acidic goblet cells increased gradually with age. Enhanced keratinization of pad epithelium, and increased teeth dimensions were age-associated characteristics. Ultrastructurally, the palatal surface of C. idella was slightly papillated at 35 mm TL after which it formed brick-like structural units that tended to cluster into longitudinally paralleled rows toward the palate-pad junction. Goblet cell openings appeared oval at 35 mm TL and became club-shaped by 210 mm TL at which the epithelium appeared compact and heavily coated in mucus. Indentations of pad surface and signs of dental wear and tear were evident ultrastructurally at 70 mm TL and onwards. The current study reports for the first time age-related developmental features of the palate and pharyngeal masticatory apparatus of grass carp. Results of the present work will help to understand aging-associated factors involving the studied fish and other related aquatic species.

Sublingual floor of Rahmani sheep (Ovis aries): A scanning electron microscopy and histomorphology analysis

The current study investigated the sublingual floor of Rahmani sheep (Ovis aries). Samples from nine healthy adult sheep have been analysed using morphometrical, scanning electron microscopic (SEM), and histological examination. The sublingual floor of the sheep was formed of a rostral prefrenular part (spatula-shaped) and two lateral sublingual recesses. Right and left sublingual caruncles were asymmetrical in length and each one had a serrated border, divided into three papillae. At higher magnifications, the three papillae of the sublingual caruncle's edge were variable in shape, with other two papillae were demonstrated underneath the caruncle. Each sublingual recess had a sublingual fold (plica sublingualis) extended from the level of frenulum linguae till the glossopalatine arch, bordered with caudolaterally directed papillae till the level of first lower molar cheek teeth. The sublingual salivary glands were mixed (seromucoid) type. The glandular lobule consisted of mucous acini and sporadic serous acini, as well as the presence of some mucous acini capped by acidophilic cells, serous demilunes. The mucous acinus was formed of pyramidal mucous cells with pale stained cytoplasm and basally located nuclei. Two ducts; major sublingual and submandibular ducts were observed within the submucosa of the sublingual caruncle. The sublingual ductal pseudostratified columnar epithelium was interspersed by more goblet cells than that of the submandibular duct. Collagen fibres around the glandular lobules, intralobular and interlobular excretory ducts as well as the connective core of the papillae were noticed. By SEM, two epithelium-lined pits on the surface of the sublingual floor mucosa caudal to the central incisive teeth were termed orobasal organ. As the first study to give a comprehensive analysis of the sheeps' sublingual floor, this one serves as a baseline for future clinical studies.

Histological and ultrastructural characterization of the dorso-ventral skin of the juvenile and the adult starry puffer fish (Arothron stellatus, Anonymous 1798)

BACKGROUND

The starry puffer fish (Arothron stellatus, Anonymous, 1798) is a poisonous tetradontidae fish inhabiting the Red sea. The skin constitutes an important defense against any external effects. The study aims to characterize the dorso-ventral skin of the juvenile and the adult starry puffer fish using light and scanning electron microscopies. Twenty specimens of juvenile and adult fresh fishes were used.

RESULTS

The scanning electron microarchitecture of the skin of the juvenile and adult fish showed delicate irregular-shaped protrusions, and well-defined bricks-like elevations on the dorsal side and interrupted folds as well as irregular-shaped protrusions on the ventral side. In adult fish, the patterned microridges of the superficial and deep epithelial cells (keratinocytes) were larger and well-defined in the dorsal skin than in the ventral side, the contrary was seen in the juvenile fish. The microridges were arranged in a fingerprint or honeycomb patterns. The openings of the mucous cells were more numerous in the dorsal skin in both age stages but more noticeable in adult. Furthermore, the sensory cells were more dominant in the juveniles than the adults. The odontic spines were only seen in adult. Histologically, few taste buds were observed in the epidermis of the dorsal skin surface of the adult fish. Both mucous and club cells were embedded in the epidermis of the juvenile and adult fish with different shapes and sizes. Melanophores were observed at the dorsal skin of both juvenile and adult fishes while fewer numbers were noticed at the ventral surfaces. Several dermal bony plates with different shapes and sizes were demonstrated in the skin of both adult and juvenile fishes.

CONCLUSION

The structural variations of skin of the juvenile and adult fishes may reflect the various environmental difficulties that they confront.

Preen gland of the laughing dove (Streptopelia senegalensis aegyptiaca): Light and electron microscopic analysis

This work reviews the microscopic anatomy of the preen gland in laughing dove (Streptopelia senegalensis aegyptiaca) using light, scanning, and transmission electron microscopes. The gland possessed two large pea-shaped lobes. The glandular lobules of each lobe were huddled in elliptical, triangle, round shapes, connected with each other by strands of connective tissue septae. The lobule was composed of glandular follicles, each follicle folded and enclosed by a sheath of connective tissue connected with the neighboring ones by interfollicular septae. The gland's parenchyma was coated with a dense connective tissue capsule composed of collagen, elastic, and reticular fibers. The secretory tubules were divided into peripheral tubules and central tubules. The central ones were located close to the major cavity and lined with thin epithelium, whereas the peripheral tubules were adjacent to the capsule and characterized by taller epithelium. The central secretory tubules were lined with four cell layers: flattened basal, large-sized polyhedral intermediate, and secretory cell layers, as well as a degenerative cells layer that formed of small cells with pale cytoplasm and pyknotic nuclei. Variable sizes and shapes of Herbst corpuscles were detected alongside the papillary duct and near the glandular lobe. Transmission electron microscopy view revealed that the cytoplasm of the intermediate cells contained a dense population of mitochondria, while the secretory and degenerative cells contained fewer mitochondria. In conclusion, these structures will be beneficial for understanding the habitat differences of laughing doves. RESEARCH HIGHLIGHTS: Grossly, the preen gland (PG) of the laughing dove formed of two large pea-shaped lobes. The glandular lobule was composed of glandular follicles, each follicle was folded and enclosed by a sheath of connective tissue connected with the neighboring ones by interfollicular septae. The central secretory tubules were lined with four cell layers: basal, intermediate, secretory, and degenerative cell layers. Variable sizes and shapes of Herbst corpuscles were detected alongside the papillary duct and near the glandular lobe of the PG. In transmission electron microscopic analysis, the cytoplasm of the intermediate cells contained a dense population of mitochondria, while the secretory and degenerative cells contained fewer mitochondria.

Morphometrical and Scanning Electron Microscopic Investigations on the Rahmani Sheep’s Tongue: Adaptive Strategies for Feeding Behaviors.. [DOI: 10.20944/preprints202306.1376.v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Abstract: The morphological characteristics of the tongue of the Rahmani sheep (Ovis aries) were described using gross inspection, morphometry analysis, and scanning electron microscopy. Nine mature male sheep heads were slaughtered, and samples were taken right away. The tongue was dissected, and various samples were obtained for SEM. The tongue had two different types of lingual papillae: mechanical (filiform, conical, and lenticular papillae) and gustatory (fungiform and vallate papillae). The main papillae and several secondary and tertiary papillae combine to produce each filiform papilla. On the dorsal surface of the tongue, there were five different types of conical papillae dispersed throughout, as well as three huge conical papillae and various-sized flattening papillae in front of the frenulum linguae. Furthermore, on the torus linguae, two different types of lenticular papillae were found. The majority of fungiform papillae possessed prominent taste buds' pores and were button-shaped with a central depression region, particularly in the rostral section of the tongue. On either side of the torus linguae, there are two rows of round, elliptical, pyramidal, and oval circumvallate papillae. Each papilla is surrounded by flat, broad, undulating annular rods and papillary grooves. The lingual surface also included numerous lin-gual gland openings in a variety of forms, which increased in number at the root. Finally, variations in the form, size, and number of lingual papillae, as well as the distribution of lingual gland openings along the lingual surface, may provide efficiency to the Rahmani sheep's tongue when feeding hard forages and high fiber foods.

Peripheral blood cells of native pig (Zovawk) of Mizoram, India: Light and scanning electron microscopy analysis

The literature on the blood cells of Zovawk pigs is scanty; thus, this study was designed to elaborate the light microscopy (LM) and scanning electron microscopy (SEM) characterization of blood cells of Zovawk pigs by LM and SEM. Twelve different blood samples were aseptically obtained from adult healthy Zovawk pigs, irrespective of sex. To determine the cytomorphological and cytochemical structures of the many produced constituents of blood, blood smears were stained with various stains. The blood samples were treated with various substrates for cytoenzymatic research, and the alterations were noted. A 1000× magnification Olympus Trinocular Research microscope was used to examine the smears. The blood samples were prepared for electron microscopy according to the standard procedure. The prepared samples were delivered to the Sophisticated Analytical Instrumentation Facility (SAIF), All India Institute of Medical Sciences (AIIMS), New Delhi, for SEM imaging. On LM, pig erythrocytes were spherical and nonnucleated. The cytoplasm of the neutrophils was spherical and included cytoplasmic granules. The eosinophils had prominent cytoplasmic granules and were round. Basophils were infrequently present and had cytoplasmic granules that were clear blue. The sizes of small, medium and large lymphocytes were noted. The monocytes were oval or circular. The platelets ranged in form from asymmetric to round. The blood samples were stained for cytochemical analyses using acid ferrocyanide stain for iron, Sudan black blue stain for lipids, toluidine blue stain for mucopolysaccharides, and periodic acid Schiff's stain for glycogen. The cytoenzymatic characteristics were evaluated and compared with substrates treated with acid phosphatase, alkaline phosphatase, peroxidase, arylsulfatase, cytochrome oxidase, beta-glucuronidase, and succinate dehydrogenase. Erythrocytes appeared as biconcave disks under SEM. Two forms of leukocytes were observed, having a rough and pointed cell surface like a flower. It can be concluded that the LM and SEM morphology of blood cells of Zovawk pigs resembled other domestic animals, however, few differences were observed among the discussed animals.

Morphological and ultrastructural features of the laryngeal mound of Egyptian Cattle Egret (Bubulcus ibis, Linnaeus, 1758)

Background

According to our acknowledgment this is the first full anatomical description of the studied laryngeal mound of the Egyptian Cattle Egret (Bubulcus ibis, Linnaeus, 1758). This study was obtained with the aid of scanning electron microscopy (SEM) and histological techniques. Heads of ten healthy adult male Egyptian cattle egrets were used in this study.

Results

The laryngeal mound (Mons laryngealis) was a pear-shaped musculoskeletal elevation. It represented 20.55 and 67.87% of the total length of the oropharyngeal floor and the pharyngeal floor, respectively. By SEM view, the lateral aspect of the caudal third of the laryngeal mound had a serrated mucosal appearance, forming of 6–7 finger-like projections. Furthermore, the terminal part of the laryngeal mound (except the middle part) was bordered a transverse row of pyramidal-shaped papillae, which demarcated from the esophagus. Histologically, laryngeal salivary glands termed (cricoarytenoid salivary glands) of the laryngeal mound were simple tubular type and were arranged in one row within the lamina propria connective tissue close to the lamina epithelialis. Those glands were surrounded by abundant aggregation of lymphocytes, extended overlying the surface lining epithelium. The glottis within the laryngeal mound was supported by hyaline cartilages; dorsally by paired arytenoid cartilages, ventrolaterally by cricoid cartilage, and caudodorsally by procricoid cartilage. Two groups of intrinsic laryngeal skeletal muscles have connected the cartilages. The glandular epithelium of the laryngeal salivary glands and chondrocytes of the laryngeal cartilages showed strongly positive alcian blue reaction.

Conclusions

The laryngeal mound shows certain features that are unique as an adaptation to lifestyles and bird’s habitat.

Comparative histological analysis of the skin for forensic investigation of some animal species

Macroscopical and histological analysis of the skin is fundamental in both human and veterinary forensic investigations. However, databases of differential skin histology of various animal species are rare. The aim of the present study is to identify species-specific differential histological features of the skin that could be used in forensic investigations including animal identification. For this purpose, skin specimens were collected from the neck region of various farm animals including buffalo, cow, camel, sheep, goat, dog, and donkey, and were processed for histological analysis. Our comparative analysis revealed specific histological features in the skin that could differentiate between the studied animal species. The epidermis layer of the skin was very thick in buffalo, intermediate in cow, sheep, goat, dog, and donkey, but very thin in camel. The papillomatous epidermis was very frequent in buffalo, but very rare in cow. In the dermis layer of the skin, four structures were located which showed differential features between the studied animal species: the papillary layer, which was thick in buffalo, camel, sheep, dog, and donkey but thin in cow and goat. The sweat glands, which were few in buffalo, cow, goat, and dog, but numerous and deeply located in the dermis of sheep; they were individually located in all studied animals except in camel and donkey they were arranged in clusters. The hair follicles were characteristic for the skin of sheep as they were present at two different levels in the dermis with simple and compound hair follicles. The sebaceous glands were large and multi-lobular in buffalo, but small and uni-lobular in cow and camel. The hypodermis layer of the skin was very thick in sheep and goat in contrast to all other analyzed animals. In conclusion, the present study provides comprehensive information on the differential histological features of the skin of seven different domestic animal species that could be used as a key in forensic investigations.

Pre-gastric secretory epithelium: A light, scanning and transmission electron microscopic study of an epithelial modification of the esophagus in embryonic quails

The current study investigated epithelial modification of embryonic quail esophagus using gross examination, light microscopy, transmission and scanning electron microscopy. By semithin sections, the pre-gastric modified region had unfolded mucosa, formed epithelial flabs and pockets, and had reduced muscularis mucosae, thin muscular layer, less glandular tissue, and outer esophageal groove. Conversely, the normal esophageal mucosa was folded, had abundant glandular tissue and prominent muscularis mucosae, with two muscular layers; the outer and the inner. The modified epithelium resembled stratified squamous type that had a high affinity for PAS, methylene blue, and PAP stains. Ultra-structural features of the modified esophageal epithelium resembled stratified squamous epithelium and contained hypertrophic Keratinocytes; dark and light. Hypertrophic keratinocytes had RER organized, few ribosomes, and developed loose bundle of cytokeratin compared with squamous keratinocytes. Hypertrophic Keratinocytes synthesize two types of granules; peripherally located small electron-dense granules and large electron-lucent granules. Hypertrophic keratinocytes had peroxisomes that were identified by the crystalline core of the urate oxidase. In conclusion, epithelia modification may have secretory function. Further studies should be carried out to explain the exact function of this type of modified epithelium.

Histomorphology and ultrastructure of the proventriculus of the broad breasted white turkey (Meleagris gallopavo, Linnaeus 1758)

This study aims to examine the functional morphology of the proventriculus of the broad breasted white turkey (BBWT) (Meleagris gallopavo, Linnaeus 1758) using gross anatomy, light microscopy, gross/histomorphometric analysis, and scanning and transmission electron microscopy. The proventriculus was characterized internally by many elevated papillae with a mound, leafy flower, and lotus flower-shapes. Each papilla was enclosed by concentrically organized mucosal folds with distinct or indistinct proventricular gland openings on its top. Longitudinal folds and grooves at the junction of the proventriculus with the esophagus exhibited various sized and shaped openings of esophageal glands with irregular outlines. Histologically, the surface epithelium of the proventriculus was covered by a thin layer of cuticle, particularly evident at its junction with the gizzard. The lamina epithelialis and propria, and secretory units of proventricular lobules were infiltrated by aggregations of lymphocytes and lymphoid follicles (nodules). Variably shaped glandular lobules of proventricular glands occupied the submucosa, surrounded by thin strands of smooth muscle fibers derived from muscularis mucosa. Triangular, cuboidal, or columnar-shaped secretory oxyntico-peptic cells lined the secretory units. Many telocytes (pyramidal or fusiform-shaped cell bodies with lengthy telopodes) were observed in interstitial tissue. Further, two types of argyrophilic endocrine cells were identified within the glandular epithelium. The morphology of the M. gallopavo proventriculus reflects its dietary habits and behavior.

Effect of chitosan and curcumin nanoparticles against skeletal muscle fibrosis at early regenerative stage of glycerol-injured rat muscles

Introduction

Chitosan and curcumin are natural products that have a wide range of beneficial effects including wound healing. However, their high molecular weight and poor water solubility limit their applications.

Aims

Therefore, the current study aims to evaluate the effects of chitosan (Cs) and curcumin (Cn) nanoparticles (NPs) on fibrosis and regeneration of glycerol-injured muscle.

Methods

Muscle injury was induced by intramuscular injection of glycerol into the tibialis anterior muscle of rats. Cs-NPs and Cn-NPs were administered at different doses intraperitoneally after injury. Injured muscles were collected at day 7 after injury, and muscle fibrosis and regeneration were assessed.

Results

The present results revealed that Cs-NPs and Cn-NPs treatment significantly decreased fibrosis index and increased the average myotube diameter with shifting of the distribution of myotube diameters towards larger diameters in a dose-dependent manner. Immunohistochemical analysis revealed that Cs-NPs and Cn-NPs treatment significantly decreased the number of CD-68⁺ cells and Col-1⁺ area. Results showed that Cn-NPs had a higher protective effect, in the form of attenuating muscle fibrosis and inflammation, and enhancing muscle regeneration, than that of Cs-NPs.

Conclusions

To our knowledge, this is the first study to document the effects of Cs-NPs in injured muscles. The results of study might be a novel approach to attenuate muscle fibrosis in humans using curcumin and chitosan nanoparticles.

Tracking the developmental events in the duodenum of the quail embryo: Using light and electron microscope

The present study described the full morphology of the duodenum of the Japanese quail during the embryonic stage from 3rd day of incubation till hatching using the light and electron (scanning and transmission) microscope. The specimens were collected, analyzed and described anatomically, morphometrically and microscopically. The first recognition of the prospective duodenum was at the 4th day of incubation and developed continuously by age progression. The prospective duodenum consisted of a flat pseudostratified epithelium, mesenchyme and covering mesothelium. On day 8th of incubation, the epithelium developed three evaginations lead to formation three previllous ridges protruding inside the duodenal lumen, which later at the 9th day differentiated into numbers of projections; villi. On the 9th day, the epithelium lined the villi transformed into a simple columnar type, the duodenal villi appeared as pyramidal-shaped projections, had wide base and narrow apex and by age progression, the duodenal villi went through changes in number, size and shape. On hatching day, the duodenal epithelium consisted of enterocytes interspersed with secretory goblet cells, which stained positive for both Periodic Acid Schiff (PAS) and Alcian blue AB and represented filled with metachromatic granules. The muscular wall started as mesenchymal condensation on the 6th day then differentiated into the circular smooth muscle layer on the 9th day of incubation. Giving detailed information about the morphological development of the duodenum during the incubation period of quail embryo helps in reaching a satisfactory explanation about how the duodenum plays a vital role in digestion, absorption and immunity.

Performance scanning electron microscopic investigations and elemental analysis of hair of the different animal species for forensic identification

Veterinary forensics have attracted less attention compared with human forensics. Animal hair morphological examination using scanning electron microscopy (SEM) and hair mineral analysis using energy-dispersive X-ray fluorescence (ED-XRF) provide reference databases for animal hair identification used in forensic investigations. This study was performed on four different animal species: large ruminants (buffalo and cattle), small ruminants (goat and sheep), carnivores (cat and dog), and equines (donkey and horse). The hair scale pattern, scale margin type, and distance between scales were identified. The hair scale pattern was imbricate in large ruminants, goat, and horse; coronal (crown-like) in carnivores and donkey; and spinous in sheep. The morphometric measurements, including cuticle layer thickness, cuticle scale height, cortex diameter, and hair shaft width were recorded. The highest cuticle thickness was found in horse, and the highest cuticle hair scale was detected in cattle. Moreover, the largest cortex diameter was measured in buffalo, whereas the smallest one was in cat. With regard the content of hair elements, some elements were specific for the hair of certain tested animals, such as bromine in sheep and magnesium and phosphorus in buffalo. In addition, vanadium and titanium were found only in cattle and dog, and the latter element was also detected in sheep. In conclusion, this study provides two techniques for animal hair identification that can be used in forensic investigations.

Scanning electron microscopy of the nasal skin in different animal species as a method for forensic identification

The current study aims to provide a new method for the identification of animal species by using the scanning electron microscopic study on the nasal skin around the nostril. The reference databases for animal identification using traditional ways (i.e., hair and bone analyses) were somewhat available. This study was conducted on the nasal skin of seven different animal species: large ruminants (Saidi buffalo and frozen Angus cattle); small ruminants (Egyptian goat and Rahmani sheep); camels (one-hump dromedary camel); equines (African domestic donkey and Arabian horse); carnivores (farm domestic cat, Egyptian Baladi dog, and red fox); swine (Danish Landrace pig); and rodents (albino rat and New Zealand white rabbit). The nasal skin was divided by grooves into different shaped raised areas in some examined animals, the mean diameter of these areas and width of the grooves of each animal species were recorded. The characteristic differential features of the nasal skin of each animal species have been documented. Few openings of the nasolabial glands were demonstrated in large ruminants and swine, which were H letter-shaped in buffaloes, oval-shaped in cattle, and whirlpool-shaped with several layers of folds on their margin in pig. Moreover, the openings of the lateral nasal glands were whirlpool, ovoid, and oval shaped in goats, sheep, and camels, respectively. In conclusion, the present study proved that the skin around the nostrils plays an important role as means of identification in forensic investigations and improves the field of veterinary forensic medicine in general, which is not well-developed in comparison with human forensics.

Developmental stages and growth of the proventriculus of post-hatching Muscovy duck: Light and electron microscopic study

The present study was implemented to provide comprehensive information on the developmental sequence of the proventriculus of Muscovy ducks by gross examination, macro-micrometric analysis and by using light microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). Samples from 55 healthy post-hatching Muscovy ducks of both sexes ranging from 1 to 60 days old. The proventriculus began cranially opposite to the cranial end of the liver at 1-15 days old, but in front this level at 30 and 60 days old. Morphometrically, the length of the proventriculus was increased by about four folds while weight by 19 folds at 60 days old when compared with those at one day old. Scanning electron microscopy of the proventricular lumen at one day old exhibited numerous small mostly rounded irregularly distributed openings of the glands, but uniformly distributed and surrounded by closely packed concentrically arranged mucosal folds resembling a rosette shape at the older ages. Histologically, in all studied stages, rounded, elongated oval or polymorphic shaped lobules of the proventricular glands were occupied within the muscularis mucosa. The tubuloalveolar secretory units lined with secretory (oxyntico-peptic) cells with variable shapes had secretory granules increased by the development. Numerous argyrophilic endocrine cells were demonstrated away from the glandular lumen at older ages. Transmission electron microscopy revealed that the cytoplasm of the secretory cells contained homogeneously electron-dense granules at a young age, but two types of these granules could be recognized at 60 days old. In conclusion, this study provides a wide difference in the morphometric and the structure of the proventriculus from one day to 60 days old. This difference between the examined age-stages may be related to the feeding strategy (behavior) and the functional adaptations from the young to the older ages.

Morphometrical, histological, and scanning electron microscopic investigations on the hard palate of Rahmani sheep (Ovis aries)

The present study investigated the hard palate of Rahmani sheep (Ovis aries). Samples from nine healthy adult male sheep were investigated using morphometrical, histological and scanning electron microscopic examination. Morphologically, the hard palate was elongated, narrow rostrally, and wide caudally. The incisive papilla was heart-shaped, flanked on both sides by a groove on which the nasopalatine duct opened. The palatine raphe was in the form of a groove that contained a ridge caudally. On both sides of the raphe, 13-15 pairs of palatine ridges were present and mainly occupying the narrow part. The wide part had a rough part that contains few ridges rostrally and a smooth part caudally. Histologically, the incisive papilla and palatine ridges were lined by a keratinized stratified squamous epithelium resting on a dense layer of lamina propria. The incisive papilla characterized by the presence of seromucoid salivary glands and hyaline cartilage fragments in the lamina propria. The salivary glands became abundant and well-developed in the wide part till the end of hard palate. All palatine salivary glands were Alcian blue-periodic acid-Schiff positive. By scanning electron microscopy, numerous gland openings were scattered on the surface of the palatine ridges. In conclusion, the hard palate of Rahmani sheep presented characteristic features, which may be related to the species differences, feeding behavior, and possible functional adaptations. This is the first study to report the presence of cartilaginous segments and salivary glands in the incisive papilla and provide detailed descriptions of the Rahmani sheep hard palate.

Histomorphological investigations on the lips of Rahmani sheep (Ovis aries): A scanning electron and light microscopic study

This study was conducted to provide comprehensive information on the anatomical and histological features of the upper (UL) and lower (LL) lips of Rahmani sheep by gross examination, morphometric analysis in addition to Light and scanning electron microscope (SEM). Samples from normal healthy adult male sheep heads were collected directly after slaughtering. UL and LL were dissected, and specimens were collected for both light and SEM. The UL was longer approximately by one-fold and thicker by one-fold at the median and the oral angle areas, and by one- and half-folds at the paramedian area than the LL. The free border of both lips was characterized rostrally by the presence of labial projections. By SEM the edges of the inner aspect of the lips and of the philtrum were distinguished by labial projections. These projections which surrounding the philtrum subdivided into polygonal areas with numerous keratinized scales especially at the apical parts which increased dorsally toward the nostril. Most of the openings of the upper labial salivary glands were volcanic crater-shaped while that of the lower labial salivary glands were various shapes; round folded margin, rosette and whirlpool shaped. Histologically, the shape of the projection or papillae differs at the median and paramedian areas of the UL than the LL. However, there was no differences near the oral angle area. In conclusion, the shape, size and amount of keratinization of the papillae may offer efficiency to the lips during feeding process.

Comparative anatomical studies on the glandular stomach of the rock pigeon (Columba livia targia) and the Egyptian laughing dove (Streptopelia senegalensis aegyptiaca)

The rock pigeon (RP) and the laughing dove (LD) are common and widely distributed species in African countries, including Egypt. The present work was carried out to characterize the comparative features of the glandular stomach (proventriculus) in these two birds, which share diets and habitats. In both species, the proventriculus is an elongated spindle obliquely situated in the cranial two-thirds of the body cavity. The length and weight of the proventriculus in the RP were about one and half times greater than that of the LD. Histologically, the proventricular wall generally consisted of the mucosa (thickest), submucosa, muscular and serosa layers. The proventricular glands occupied most of the wall of the proventriculus within the lamina propria of the mucosa. The glands are tubuloalveolar in type, consist of variable shaped lobules and are more condensed in LD than in RP. At the proventricular-gizzard junction (PGJ), the proventricular glands were observed external to the tubular glands of the gizzard in the RP, whereas in LD, these glands end abruptly and are separated from the tubular glands of the gizzard by a short distance. A scanning electron microscopy (SEM) of the proventricular lumen in RP revealed that the openings of the proventricular glands have an irregular outline surrounded by concentrically arranged mucosal folds that resemble a rosette shape. In the LD, these openings have a regular outline surrounded by thinner, widely spaced mucosal folds. To our knowledge, these results identified the structure of the proventriculus in RP and LD for the first time.