Meckel's Diverticulum in Adult Geese (Alopochen egyptiacus): A Comprehensive Study of Structure Using Histological, Electron Microscopy, and Immunohistochemical Methods.

The intestine plays an important role in mediating between the bird and its nutritional environment. The yolk stalk, also known as Meckel's diverticulum, is a landmark between the jejunum and ileum. This work aimed to investigate the anatomical, histological, and electron microscopical features of cellular components of the Meckel's diverticulum (MD) in adult geese. The intestine was dissected from the bird's body cavity, and Meckel's diverticulum was exposed and prepared for light and electron microscopical examinations. Our results revealed that the MD mucosa is thrown up into villi and crypts, and the mucosal epithelium is a columnar epithelium with goblet cells as well as intraepithelial lymphocytes. Lymphoid follicles and numerous immune cells were demonstrated within the lamina propria. The mucous glands were also observed within the lamina propria and amongst the lymphoid follicles. The lining epithelium of MD appeared with different staining affinities: dark cells (electron-dense) and light cells (electron-lucent) contained few mitochondria and more secretory vesicles, while dark cells contained more mitochondria and fewer secretory vesicles. Immunohistochemical analysis of MD revealed positive immunoreactivity for several markers, such as CD 117, chromogranin, PLCß, cytokeratin, MHC II, and S 100. Taken together, our findings suggest that MD is considered an immune organ in adult geese.

Morphology of the soft palate and palatine tonsil of the goat (Capra hyricus).

The present study was carried out to study the morphology of the goat's soft palate and palatine tonsil by gross anatomy, morphometry, light and scanning electron microscopy (SEM). Twelve heads of normal adult (18-24 months) apparently healthy goats of both sexes were collected from local commercial slaughterhouses in Qena Governorate, Egypt. The oral cavity was dissected, and samples were collected for both light and SEM. The soft palate of the goat formed the caudal continuation of the hard palate. It was relatively short, it extended from the level of the caudal border of the last upper molar tooth to terminate caudally against the base of the epiglottis. The oral mucous membrane of the soft palate was covered by non-keratinized stratified squamous epithelium. The lamina propria and submucosa contained connective tissue fibers, diffuse and nodular lymphatic tissue, striated muscle fibers, and a large number of mucous and serous palatine glands. By SEM, the ventral surface had several rounded openings occupied by flower-like structures. These openings represented the entrances to the palatine glands. The palatine tonsil was large and protruded from a fossa in the lateral wall of the oropharynx. It had 2-3 elongated irregular openings that lead to the underlying crypts. These crypts were well-developed and lined by non-keratinized stratified squamous epithelium. The epithelium of the tonsillar crypts directly covered lymphoid tissue and was infiltrated by lymphocytes. Tonsillar glands of pure mucous type were demonstrated. In conclusion, the study provides the basic morphological features of soft palate, as well as the palatine tonsil of the goat by gross observation, light and SEM. The palatine tonsils of goat were well-developed with extensive crypt system, suggesting their essential role in the immunological response against antigens that enter through the oral cavity. The current findings may be useful to understand the role of the palatine tonsil in immunity and disease pathogenesis. RESEARCH HIGHLIGHTS: The study reported the basic morphological features of soft palate and palatine tonsil of goat. The ventral surface of the soft palate had several rounded openings occupied by flower-like structures. The palatine tonsils of goat were well-developed with extensive crypt system. The findings might help to understand the role of the palatine tonsil in immunity and disease pathogenesis.

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.

Morph-anatomic and histochemical study of ileum of goose (Alopochen egyptiacus) with special references to immune cells, mucous and serous goblet cells, telocytes, and dark and light smooth muscle fibers.

The morphological characteristics of the ileum of 20 adult male Egyptian geese were determined using LM, SEM, and TEM. The mean length of the ileum in the male goose was approximately 158.71 mm, representing nearly 10.19% of the total length of the small intestine. The ileum is composed of four layers: mucosa, submucosa, muscular layer, and serosa. The mucosal layer comprises the epithelium, lamina propria, and muscularis mucosa. The mucosa forms finger-like villi and is invaginated at the bases, forming the crypts of Lieberkühn. The ileum is lined by simple columnar epithelium that contains absorptive dark and light enterocytes with two types of goblet cells (mucous and serous varieties) microfold like cells, dendritic reticulum cells, Paneth cells, and a closed type of enteroendocrine cells. The lamina propria has diffuse lymphoid tissue containing lymphocytes, macrophages, mast cells, plasma cells, and heterophils as well as telocytes. The muscularis mucosa comprises circular smooth muscle fibers extending into the core of the villi. The submucosa is a thin layer of elastic-rich connective tissue. The muscular level consists of four layers, with light and dark smooth muscle fibers. We described in detail the structure of all cellular components and histomorphometric measurements.

Morphological and scanning electron microscopic studies of the lingual papillae of the tongue of the goat (Capra hircus).

The morphology of different lingual papillae of the Egyptian goats was studied by gross observation, scanning electron microscopy, and light microscopy. According to function, two types of papillae were present; mechanical (filiform, conical and lenticular papillae) and gustatory papillae (fungiform and vallate papillae). Two types of filiform papillae were detected with different shape and position. Moreover, two types of conical and lenticular papillae could be recognized on the lingual torus. Abundant fungiform papillae were found on the dorsal and ventral surfaces of the tip of the tongue. The vallate papillae had also different shapes. Taste buds were demonstrated within the epithelium of the dorsal surfaces of the fungiform papillae and the lateral surfaces of the vallate papillae. In addition, a longitudinal row of large papillae was located on the lateral aspect of the tongue in relation to the filiform papillae. These papillae were suggested to be called elongated conical papillae and may be considered as ones of the lingual papillae. In conclusion, the current study provides a detailed description of the different lingual papillae of the Egyptian goat's tongue. Presence of different types and shapes of mechanical and gustatory lingual papillae in goats' tongue suggests a high degree of functional adaptation to their diet.

Morphological investigations on the lips and cheeks of the goat (Capra hircus): A scanning electron and light microscopic study.

The current study was done to provide comprehensive information on the anatomical features of the lips and cheeks of the goat by gross examination and morphometric analysis in addition to scanning electron microscope (SEM). Samples from 12 normal healthy adult goat's heads of both sexes were collected directly after slaughtering. The lips and cheeks were dissected, and specimens were collected for both light and SEM. The lips of goat were soft and mobile. The free border of both lips was characterized rostrally by the presence of labial projections. The number, size, and arrangement of labial projections differed in the upper and lower lips. On the other hand, the buccal papillae were arranged into 6-8 longitudinal rows parallel to the cheek teeth. The length of these papillae decreased caudally while they were absent on the most caudal part of the cheek. Presence of several types and shapes of labial projections and papillae, and buccal papillae suggest a high degree of mechanical adaptation of the lips and cheeks of the goat. This study provides baseline data for clinical studies. This study is the first report to shed light on the morphology of the lips and cheeks of the goat by gross and scanning electron microscopy.

Morphological study of the hard palate in the Egyptian goats (Capra hircus): A scanning electron microscopic study.

The aim of this study was to investigate the morphology of the goat hard palate by light and scanning electron microscopy (SEM), in addition to gross and morphometric analysis. A total of twelve goat heads, from normal adult and apparently healthy goats of both sexes, were collected from local slaughterhouses in Qena province, Egypt. Samples were subjected to gross examination, morphometric analysis, light microscopy and SEM. The hard palate in the goats was long and could be divided into a rostral narrow part and a caudal wide part with about 12-15 transverse palatine ridges from which the rostral palatine ridges were serrated on their free caudal edges. The dental pad replaced the upper incisors; its caudal border had a serrated appearance. At higher magnification, the epithelial surface of the palatine rugae and incisive papilla revealed a variety in the shape of the microplicae and the pattern of the micropits. These adaptations of the goat's hard palate might increase its efficiency during ingestion and mastication of coarse roughages and in directing the food backwards. To our knowledge, this is the first study showed the detailed anatomical description of the hard palate of the goat with SEM.

Identification of morphological markers of sarcopenia at early stage of aging in skeletal muscle of mice.

The gastrocnemius muscle (GM) of young (3months) and aged (12months) female wild-type C57/BL6 mice was examined by light and electron microscopy, looking for the presence of structural changes at early stage of the aging process. Morphometrical parameters including body and gastrocnemius weights, number and type of muscle fibers, cross section area (CSA), perimeter, and Feret's diameter of single muscle fiber, were measured. Moreover, lengths of the sarcomere, A-band, I-band, H-zone, and number and CSA of intermyofibrillar mitochondria (IFM), were also determined. The results provide evidence that 12month-old mice had significant changes on skeletal muscle structure, beginning with the reduction of gastrocnemius weight to body weight ratio, compatible with an early loss of skeletal muscle function and strength. Moreover, light microscopy revealed increased muscle fibers size, with a significant increase on their CSA, perimeter, and diameter of both type I and type II muscle fibers, and a reduction in the percentage of muscle area occupied by type II fibers. Enhanced connective tissue infiltrations, and the presence of centrally nucleated muscle fibers, were also found in aged mice. These changes may underlie an attempt to compensate the loss of muscle mass and muscle fibers number. Furthermore, electron microscopy discovered a significant age-dependent increase in the length of sarcomeres, I and H bands, and reduction on the overlapped actin/myosin length, supporting contractile force loss with age. Electron microscopy also showed an increased number and CSA of IFM with age, which may reveal more endurance at 12months of age. Together, mice at early stage of aging already show significant changes in gastrocnemius muscle morphology and ultrastructure that are suggestive of the onset of sarcopenia.