Proventricular Glands Research Articles

Gross Anatomical, Histological, Histochemical and Scanning Electron Microscopic Examination of Glandular Stomach of Chinese Goose (Anser cygnoides)

Background: The digestive system is responsible for the intake, conversion and absorption of nutrients and the elimination of wastes from the body in order to provide the necessary energy for the continuation of vitality and functions. The aim of this study was to examine the glandular stomach of the Chinese goose (Anser cygnoides) by histological, histochemical and scanning electron microscopic methods. Methods: The glandular stomachs of 12 (6 males and 6 females) healthy adult Chinese geese (Anser cygnoides) were used in the study. The tissues taken were subjected to routine histological procedures. Result: Gross anatomically, it was seen that the Proventriculus was a fusiform or spindle-shaped organ, extending along the median plane between the esophagus and the muscular stomach. Scanning electron microscopic (SEM) observations revealed that the glandular stomach surface of Chinese goose (Anser cygnoides) contained many mucosal folds. Parallel grooves and proventricular gland openings were observed between these folds. Histologically, it was observed that the glandular stomach wall of Chinese goose (Anser cygnoides) consisted of four layers: tunica mucosa, submucosa, tunica muscularis and tunica serosa. The tunica mucosa was observed to have lamina epithelialis, lamina propria and lamina muscularis sublayers. Single layer prismatic cells secreting mucus were found in the lamina epithelialis layer. These cells showed local Alcian Blue (AB) pH:2,5 positive reaction. Lamina muscularis consisted of longitudinal smooth muscle fiber bundles. Compound, branched tubular glands were observed in the submucosal layer. Again, a regional AB positive reaction was observed in the lumen-facing parts of the tubular glands. Periodic acid Schiff (PAS) positive reaction was noted in the basal parts of the tubular glands. In Gordon-Sweet (GS) staining method, reticular threads easily distinguished in all areas where connective tissue present.

Newcastle disease (ND) in laying birds in Asaba, Delta State: A Case Report

This is a case report of Newcastle disease in 52 weeks old laying birds with flock size of 2,500 birds and average weight of 1.7kg. The client presented history of continuous deaths and poor laying performance. The clinical signs observed in this case study were mortalities, low egg production, depression, nasal discharge, weakness, and diarrhoea (perineum matted with greenish faeces). Post-mortem investigation revealed haemorrhagic caecal tonsils, enteritis, slightly enlarged and friable liver with areas of discolouration and pin point haemorrhages on pro-ventricular glands. Blood samples were collected from 10 birds and the sera subjected to Haemagglutination and Heamagglutination Inhibition (HI) tests using known NDV (LaSota strain). Low Newcastle disease virus (NDV) antibody titres were detected from the sera samples suggesting that the birds were not protected against ND. The flock was managed by re-vaccination using NDV LaSota strain, followed by administration of a vitamins-mineral supplement, antibiotics, glucose and an analgesic and the treatment yielded favourable therapeutic results. The farmer was advised to apply strict biosecurity measures.

Sequential histopathological changes of the lower respiratory and gastrointestinal tracts in chickens infected with velogenic Newcastle disease virus

Velogenic Newcastle disease is a highly contagious and fatal disease that affects domestic poultry, and is clinically manifested by haemorrhagic gastroenteritis and respiratory distress. This study investigated the sequential histopathogic changes in the lungs, proventriculus, and intestines of broiler chickens infected with velogenic Newcastle disease virus (vNDV). Fifty broiler chickens (6-weeks-old) were randomly assigned into two groups of 25 each: UC – unvaccinated with Newcastle disease (ND) vaccines and intranasallly inoculated with vNDV, UU – unvaccinated uninfected. At 4, 5 and 6 days post-infection (d.p.i) tissue samples were collected from birds in each group for histopathology. The lungs showed hyperaemia, haemorrhages, inflammatory oedema and cellular infiltrations in the secondary bronchi, parabronchi (atria, infundibular, air and blood capillaries of the exchange tissue), depletion of bronchial-asociated lymphoid tissues, loss of cilia and hyperplasia of surface epithelium of bronchi and parabronchi at 4 d.p.i. The lesions progressed to collapsed air capillaries with fibroplasia and fibrosis of the area at 6 d.p.i. Similar inflammatory changes were observed in the proventriculus, but accompanied by degeneration and attenuation of surface epithelium of proventiculus and proventricular glands at 4 d.p.i., and severe necrosis and disintegration of the proventricular glands at 6 d.p.i. The intestine showed severe inflammatory changes in the mucosa, submucosa and serosa and depletion of gut-associated lymphoid tissues at 4 d.p.i., and ulcerative enteritis at 5 d.p.i. The lumen was filled with necrotic debris at 6 d.p.i. This study reinforces the concept making pathologic animal experiments important tools for a complete characterization of strains in susceptible animals, as this information will be helpful in the accurate diagnosis of velogenic Newcastle disease in chickens.

Morphological studies on the prehatching development of the glandular stomach of Japanese quails using light, electron, and fluorescent microscopy

The development of the glandular stomach was studied using light, electron, and fluorescent microscopy. The research used 130 Japanese quail eggs from the second to the seventeenth days of incubation.The proventriculus could be distinguished on the3rd day. Its wall consisted of four tunics: tunica mucosa, very thin tunica submucosa, tunica muscularis, and outermost tunica serosa. Mucosal folds appeared on the 8th day. The luminal epithelium was pseudostratified columnar in type and transformed into simple columnar by the 10th day. The mucosal papillae emerged on the 11th day, spiraled on the 15th day, and had a distinct whorled look by the 17th day. Two types of proventricular glands were recognized: compound tubuloalveolar and simple tubular glands. Both types were situated within the tunica mucosa. On the 4th day, the compound glands emerged as evaginations of the lining epithelium. It began to branch on the 8th day and became well established by the 11th day. The simple glands appeared on the 11th day as localized down-growths of the luminal epithelium forming solid cords. On the 15th day, many of them showed complete canalization. On the 8th day, the muscular coat was differentiated into the lamina muscularis mucosae and tunica muscularis.

Localization of alpha 2,6-linked sialic acid residues in gastrointestinal tract compartments of some tetrapod’s representatives: Comparative histochemical study

Epithelial mucins composed mainly of glycoproteins and play a vital role as protective barrier against a variety of harmful molecules and microbial infection. Additionally sialic acids, like glycoproteins, are considered as a main component of epithelial mucins and play an important role in mucosal immunity. For example, alpha 2,6-linked galactose/N-acetyl-galactosamine (Gal/GalNAc) sialic acid residues can recognize and mask different biological sites in some intermolecular or intercellular interactions. In this study, the localization sites relationship between general mucins and alpha 2,6-linked Gal/GalNAc sialic acid residues in different compartments in gastrointestinal tract (GIT) of tetrapod representatives were investigated using lectin histochemistry. The toad (Bufo regularis), lizard (Trachylepis quinquetaeniata), pigeon (Columba livia domestica) and mouse (Mus musculus) were used as amphibian, reptilian, avian and mammalian representatives respectively. In general, the biodistribution sites of mucins are localized in most compartment sites and partially overlapped with the sites of sialic acid residues in some compartment in each animal representative. Additionally, the localization sites of both mucins and sialic acid in the GIT regions differ based on the tissue type in each tetrapod representative. The mucosa of oesophagus in the toad and lizard showed higher positive signal of general mucins compared with other tetrapod representatives. However, the mucosa of the oesophagus in the toad revealed a positive signal of sialic acid in the tubular glands only, whereas the lizard’s mucosa showed a positive signal of sialic acid in the goblet cells. Additionally, the pigeon’s oesophagus showed no localization of the sialic acid or mucins while, all layers of the mouse’s oesophagus showed a positive localization of the sialic acid residues. In the stomach, all stomach mucosa compartments in all representatives showed positive signal of mucins, while the gastric glands in the toad, pigeon (proventricular glands) and mouse showed signals of sialic acid residues localization but in different trends. While the lizard showed a localization of the sialic acid in the mucosal lamina propria only. Furthermore, the mucosa of the ileum showed positive signal of mucin in the goblet cells and some absorptive cells brush borders in all tetrapod animals. While a higher signal of the sialic acid residues in the absorptive cells but not the goblet cells in the case of the toad and mouse. While the lizard’s ileum showed a higher localization of sialic acid in the goblet cells only. Mucin localization in the rectum was similar to those in ileum. Specifically, the toad and lizard showed signals of the sialic acid residues in the goblet cells only, while the mouse’s rectum showed a higher signal of sialic acids in the absorptive cells and lamina propria but not in the goblet cells. The present study introduces important data about the biodistribution and localization profiles of general mucins and sialic acids residues in the GIT different compartments in each representative of tetrapoda animals. Further studies are needed to investigate the important role of sialic acid residues localization in different compartments of GIT mucosa.

Morphometrical and Histochemical study of glandular stomach (Proventriculus) in local domestic male ducks (Anas Platyrhynchos)

The present work explores morphometric and histochemical foundations of the wall of proventriculus in adult domestic male ducks. To achieve this study, six healthy adult ducks were purchased from local vendors in Mosul province. All birds were sedated. Their stomachs were removed after being dissected to achieve the gross description and measurements of the proventriculus, including the length and diameter of cranial, middle, and caudal regions of the proventriculus. Small tissue pieces 6-8 mm in length from three regions of proventriculus were processed for histomorphological studies using hematoxylin and Eosin stain, combined PAS-AB pH 2.5, toluidine blue, and Masson's trichrome stains. The finding showed that the proventriculus connects with the esophagus from the cranial side and the muscular stomach from the caudal side. It was a thin elongated oval tubular organ. Histologically, the mucosa of the proventriculus revealed the presence of folds and sulci-like structures covered by simple columnar epithelium. The tunica submucosa consisted of many signs of profound and straightforward sub-mucosal glands supported by connective tissue septa and extended from the basal part of the diverged gland through the lamina propria, which was organized in a conical manner (adenomere). Tunica Muscularis appeared as a double-layer coordinated in the form of inner longitudinal and outer circular ones. Finally, serosa consists of fibrous tissue, vessels, fatty tissue, and nerve plexuses studded by the mesothelial cells. The highest thickness of the four layers of mucosal, submucosal, muscular, and serosal layers in the distal part of ‎the proventriculus. Histochemical PAS staining positively reacted with epithelial tunica mucosa and wall of proventricular glands.

Anatomical, histochemical, and immunohistochemical observations on the gastrointestinal tract of Gallinula chloropus (Aves: Rallidae)

BackgroundGallinula chloropus (Linnaeus, 1758) is a wild aquatic omnivorous bird characterized by a marked resistance to harsh environmental conditions and a worldwide distribution. In this study, anatomical, morphometrical, histochemical, and immunohistochemical techniques were employed to study the structure of the gastrointestinal tract of Gallinula chloropus.ResultsThe esophagus appeared tubular with no distinct crop. Both superficial (SPG) and deep (DPG) proventricular glands were present. The DPG filled about two-thirds of the total wall thickness. Histochemically, the mucosubstances revealed mixed alcian blue-PAS positive reactions. They were mainly localized in the acini of the esophageal glands and SPG, gastric surface epithelium, duct system of DPG, and intestinal goblet cells. The highest number of goblet cells per every 1 mm2 of the intestinal mucosa was seen within the ileum and rectum, 2555 ± 468 and 2607 ± 653 respectively. Notably, glucagon immunoreactive (IR) cells were abundant in the mucosa of the small and large intestines and the proventriculus, while somatostatin IR cells were concentrated within the acini of the DPG. IR cells for the mitosis marker phospho-histone H3 (PHH3) were highest within the entire intestinal crypts and mucosa-associated lymphoid tissues (MALT). In contrast, cells IR for the apoptosis marker C.CASP3 were remarkable in epithelial cells at the tips of intestinal villi and in MALT, reflecting the dynamic nature of the latter mentioned structures.ConclusionsThe findings of the present study advance our knowledge of the gross and microscopic anatomy of the gastrointestinal tract in wild birds and could help to enhance the productivity of Aves via improving gut health.

Histochemical study of proventriculus in pre-hatch and post-hatch days in northern bobwhite quail (Colinus virginianus)

The present study was designed to investigate the histochemical developmental changes of the proventriculus at pre-hatching and post-hatching in the northern bobwhite quail at periods 11- and 15-days pre-hatching in addition to 14- and 21-days post-hatching. The proventriculus composed of four tunics is tunica mucosa, tunica sub-mucosa, tunica muscularis, and tunica serosa. The tunica mucosa was lined with simple columnar epithelium and the height of epithelium increases with the age also the thickness of the mucosa, the tunica submucosa filled with proventricular glands at 14- and 21-day post-hatch and the gland was height in diameters while in 11- and 15-day pre-hatch the gland less in diameter and the sub mucosa does not fill with the gland. Tunica muscularis was thicker in post-hatch than in pre-hatch, 11- and 15- day pre-hatch composed of a thin inner circular layer and thick outer longitudinal layer but in 14- and 21-day post-hatch the tunica muscularis was composed of a thin inner and outer circular layer and thick middle longitudinal layer. The mucosa and proventriculus glands give a positive reaction for Alcian blue stain and a weak to moderate reaction for periodic acid Schiff stain at pre-hatch, while at post-hatch the mucosa gives a positive reaction for Alcian blue stain and a negative reaction for periodic acid Schiff stain and the proventricular glands give a positive reaction for Alcian blue and periodic acid Schiff stains.

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.

Histomorphological, histochemical and scanning electron microscopic investigation of the proventriculus (Ventriculus glandularis) of the hooded crow (Corvus cornix).

The current investigation aimed to clarify the histomorphological features, scanning electron microscopy (SEM) and histochemistry of the proventriculus in the adult hooded crow (Corvus cornix). Twenty-two adult birds of both sexes were collected from El-Fayoum and Beni-Suef governorates, Egypt; ten were used for anatomical investigation, two were scanned using SEM, and ten were subjected to routine histological technique. The obtained anatomical results revealed a small-sized spindle-shaped proventriculus obliquely located in the left ventral part of the body cavity with an average body weight, length and diameter of 1.689±0.231gm, 1.54±0.383cm and 3.51±0.416cm, respectively. The histological examination revealed a typical tubular organ. The mucosa exhibited several plicae and sulci that were lined with simple columnar cells. The lamina propria was composed of collagenous connective tissue infiltrated by lymphocytes, lymphatic aggregations and tubular glands. The submucosa consisted of collagenic fibres and compound tubuloalveolar glandular lobules lined with oxynticopeptic cells and enteroendocrine cells. The oxynticopeptic cells reacted negatively with PAS and Alcian Blue stains, whereas the ductal cells reacted positively with PAS only. Enteroendocrine cells were seen singly in the lamina epithelialis mucosae and were abundant in submucosal glands. The tunica musclaris was arranged in two layers covered by serosa. The proventricular glands' openings were noticed by SEM as raised tubes with regular circular outlines surrounded by anastomosed microscopic folds. The obtained histomorphological structure of the hooded crow's proventriculus revealed some shared morphological features with most species of birds and some variations that might be attributed to their diet and feeding behaviour.

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.

Evaluation of Avian Reovirus S1133 Vaccine Strain in Neonatal Broiler Chickens in Gastrointestinal Integrity and Performance in a Large-Scale Commercial Field Trial

Avian reovirus (ARV) is the principal cause of several diseases. The vaccination of breeders allows for the control of viral arthritis and delivery of maternal-derived antibodies to the progeny. The vaccination of broiler chickens with ARV strain S1133 is used to prevent viral arthritis. However, the post-vaccination enteric effects have not been well-characterized. The purpose of this study was to evaluate the effect of vaccination with the S1133 strain on the weight gain and feed conversion of broiler chickens and to characterize the gastric, enteric, and pancreatic lesions that the strain could induce. A total of 672,000 chickens were divided into two groups: a group vaccinated with ARV strain S1133 (S1133ARV) and a control group (not vaccinated). Upon histological analysis, the vaccine group showed less proventricular glandular tissue and atrophy of the pancreas and duodenal villi, as well as having a lower average daily profit. The conclusion based on the results of this investigation is that neonatal vaccination with S1133ARV causes atrophy of the pancreatic acini, proventricular glands, and intestinal villi, leading to an increased diameter of the glandular lumen and atrophy of the enteric villous, as well as weight loss, in broiler chickens.

A focus on the gross morphological and ultrastructural characteristics of the oesophagus and stomach of Eurasian common moorhen (Gallinula chloropus chloropus, Linnaeus 1758)

The present work was the first attempt to examine the oesophagus and stomach of the Eurasian common moorhen grossly and by SEM. The oesophagus was composed of long cervical and short thoracic parts. The longitudinal folds of the cervical part were narrower than that of the thoracic part, while the depressions between these folds were shallower and wider in the cervical part. On the epithelial surface of the oesophagus, micropapillae were present and they were numerous and smaller at the level of the cervical part. The openings of the oesophageal glands were circular at the level of the cervical part and oval to elliptical at the thoracic part. The crop was absent. The proventriculus was fusiform in shape; its mucosa was arranged in several, concentrically arranged mucosal folds connected with each other by transverse folds. The proventriculus glands were oval and opened by raised papillae on the epithelial surface. The gizzard was oval; its mucosa was lined by a horizontal layer of cuticle appeared like the fish scales, while the vertical part of the cuticle appeared as thin rods. The folds of the oesophagus are functioning for the expansion for the passage of the food particles. The tunica musculosa of the gizzard was thick to help in grinding of the food particles.

Histomorphological and Histochemical Studies on Proventriculus in Guinea Fowl (Numida meleagris)

Background: The proventriculus, component of digestive system of bird secretes hydrochloric acid and pepsinogen which helps the churning of food material that takes place in ventriculus. Pepsinogen produces pepsin and it smashes the peptide bonds of amino acid of food material. Methods: The twelve proventriculus samples of Guinea fowl birds were fixed in 10% neutral buffered formalin and Bouin’s fluid for histological procedure while chilled acetone and chilled ethanol were used as the fixatives for histochemical studies. The fresh unfixed samples were used on cryostat for studies of succinic dehydrogenase enzyme.Result: Histomorphologically the proventriculus of Guinea fowl was observed as the typical tubular component with four tunics from inside to outside as tunica mucosa, tunica sub mucosa, tunica muscularis and tunica serosa. The submucosal layer comprised with proventricular submucosal gland (PVSMG) which was encapsulated by elastic fibers. Tunica muscularis was inner longitudinal and outer circular layer, while the tunica serosa was observed with surrounding adipose tissue as the connective tissue constituent to endow the access of nutritional supply in the form of blood vessels. The luminal surface of proventricular submucosal glands has shown the significant activity of glycogen while intercalated, intralobular and interlobular ducts have exhibited the weak activity towards the same. The glandular cell rod of PVSMG, serosal layer and adjoining connective tissue with blood vessels has exhibited very weak activity of alkaline phosphatase. Mucosal folds and lumen of PVSMG has shown the weak activity of acidic phosphatase but the serosal limiting membrane has shown very weak activity. The succinic dehydrogenase activity was seen in the connective tissue septa of submucosal glandular cellular rods and the intense activity was observed at tunica muscularis.

Pathogenicity of Two Nematodes Tetramerese sp. and Microtetramerese Spiralis in Proventriculus of Some Aquatic Birds from Al-Sanaf Marshes in Thi-Qar Province, South of Iraq

The present study was carried out to investigate the prevalence and mean of intensity of two nematodes Tetramerese sp. and Microtetrameresespiralis isolated from some of aquatic birds collected from Al-Sanaf marshes, Thi-Qar province.The pathological effects of these parasites on the tissues of the infected aquatic birds were recorded.TheTetramerese sp. females were embedded in glands of proventriculus of the some aquatic birds including: Ardea ralloides, Egretta garazeta, Nycticorax nycticorax, Himantopus himantopus, Larus genei, Bubulicus ibis, Aredea purpurea and Anas clypeata with prevalence 12.57% and mean of intensity 3.00, while the Microtetrameresespiralis embedded in gastric glands of proventriculus of Bubulicusibis with prevalence 10% and mean of intensity 25.00.Histopathological examination of infected tissues showed dilation of the proventericular gland lumen, atrophy, necrosis and degeneration of the glandular cells of proventriculus

Pathogenicity of Two Nematodes Tetramerese sp. and Microtetramerese Spiralis in Proventriculus of Some Aquatic Birds from Al-Sanaf Marshes in Thi-Qar Province, South of Iraq

The present study was carried out to investigate the prevalence and mean of intensity of two nematodes Tetramerese sp. and Microtetrameresespiralis isolated from some of aquatic birds collected from Al-Sanaf marshes, Thi-Qar province.The pathological effects of these parasites on the tissues of the infected aquatic birds were recorded.TheTetramerese sp. females were embedded in glands of proventriculus of the some aquatic birds including: Ardea ralloides, Egretta garazeta, Nycticorax nycticorax, Himantopus himantopus, Larus genei, Bubulicus ibis, Aredea purpurea and Anas clypeata with prevalence 12.57% and mean of intensity 3.00, while the Microtetrameresespiralis embedded in gastric glands of proventriculus of Bubulicusibis with prevalence 10% and mean of intensity 25.00.Histopathological examination of infected tissues showed dilation of the proventericular gland lumen, atrophy, necrosis and degeneration of the glandular cells of proventriculus

Morphological features of the gastrointestinal tract of Garganey (Anas querquedula, Linnaeus 1758)-Oesophagus to coprodeum.

The present work was aimed to study the gastrointestinal tract in Garganey from the oesophagus to coprodeum by the aid of the gross morphology, scanning electron microscopy and histology. At the level of the thoracic inlet, the oesophagus had a thick part which had numerous tortuous longitudinal folds carried transverse folds on them. Histologically, the thick part had thick epithelium and appeared more folded with more and larger glands. The mucosa of the proventriculus had mucosal folds appeared as a leaf-like with rounded tips. The openings of the proventriculus glands were projected with papillae on the epithelial surface. The gizzard lined with horizontal layer of cuticle which sent vertical parts of cuticle. The duodenal villi were pentagonal in shape with sharply pointed tips, while the jejunal villi were triangular with rounded ends, and the ileal villi were wide and pentagonal in shape with pointed tips. The mucosa of the duodenum, jejunum and ileum was thrown into villi lined by simple columnar epithelium with goblet cells with difference in the form, length, density and number. The apical points of the duodenal and ileal villi appeared pointed, while the jejunal villi had rounded ends. The jejunal villi were longer and numerous than the duodenal villi, but the ileal villi appeared with different length and less numerous. The mucosa of the caecum had numerous mucous glands which surrounded by circular crypts. The rectal mucosa had longitudinal folds and semilunar and circular crypts. The mucosa of the coprodeum had longitudinal folds surrounded by crypts.

Histochemical and immunohistochemical adaptations on the gastroesophageal tube of the blue‐fronted parrot (Amazona aestiva Linnaeus, 1758)

AbstractAmazona aestiva Linnaeus, 1758 is known as the blue‐fronted parrot. These animals are considered seed dispersion, contributing to ecological balance. Despite its ecological importance, A. aestiva is listed as an imminent danger of becoming extinct, as it is one of the most illegally traded native species in Brazil, besides losing its habitat due to deforestation and forest fires. The cranial oesophagus mucosa is lined with a non‐keratinized stratified squamous epithelium, and the basal layer presents melanocyte accumulation. No mucous glands were observed in the lamina propria/submucosa. The ingluvium two different muscular layer patterns were observed, one internal and circular and one very thick, external and longitudinal. The proventriculum submucosa consists of polygonal proventricular glands and contents into a broad central duct lined with simple columnar epithelium Periodic acid‐reactive Schiff positive (PAS+) and Alcian blue positive (AB+). The 5‐HT cells are dispersed in the proventricular glands located at base and apex. The ventricle mucous layer contains numerous branched folds lined by a simple columnar epithelium. The epithelium was negative reaction for PAS and positive for AB only on the fold surfaces. The 5‐HT cells were scarce and observed only at the base of the ventricular gland, as well as in the adjacent connective tissue.

The morphological development of the proventriculus of Dandarawi chick: Light and electron microscopical studies

This study was carried out on 40chick embryos collected from incubated eggs of Dandarawi chicken (Gallus gallus domesticus) on the 5th to 19th incubation day (27 to 45 Hamburger and Hamilton, H&H stages). In addition, 15 chicks were collected on the day of hatching (stage 46 H&H), one week and two weeks post-hatching to demonstrate the histological, histochemical, and electron microscopic developmental changes of the proventriculus (of the digestive tract). Histologically, the proventriculus was observed as a narrow tube at 27 H&H stage. It was lined by pseudostratified columnar epithelium through 27-39 H&H stages and from the stage 43 till post-hatching, it was lined by simple columnar epithelium. The Lamina muscularis mucosa could be identified at stage 43. The proventricular glands were detected firstly at stage 31 and branching at stage 35. Histochemically, the surface epithelium and proventricular glands reacted positively to PAS, alcian blue and bromophenol blue from stage 31 till maturity. The glands displayed an apocrine mode of secretion at stage 39 and their cytoplasm contained abundant mitochondria, RER, secretory granules, and lipid droplets. Enteroendocrine cells could be observed among the glandular and surface epithelium at stage 45 H&H. The interstitial tissue contained fibroblasts and telocytes. The telocytes were firstly detected at stage 35 H&H and composed of a cell body and two long cell processes called telopodes. The tunica muscularis differentiated into three layers of smooth muscle fibers at stage 37 H&H. The cellular and stromal organizations of the proventriculus and their relations to the development and function were discussed.

Histological and histochemical study of the proventriculus (Ventriculus glandularis) of common starling (Sturnus vulgaris).

The histological and histochemical structures of the proventriculus of starling (Sturnus vulgaris) were examined using haematoxylin and eosin and special staining, that is periodic acid schiff (PAS), Masson's trichrome, Alcian blue, Orcein and Reticulin. All three cranial, middle and caudal parts of the proventriculus were also studied. The study results showed that the wall of the proventriculus consisted of mucosal, submucosal, muscular and serosal tunics. The mucosal tunic presented folds and sulci on its luminal surface. In the first third of the proventriculus, the tunica mucosa characterized by presence of folds lined by stratified squamous epithelium and presence of simple tubular glands in the lamina propria. In the middle and caudal thirds of the proventriculus, the surface was covered by a columnar epithelium, and the branched tubular glands were extended through the lamina propria. From the base of the branched tubular glands, the deep proventricular glands were observed that were compound tubuloalveolar lobules. The surface epithelium of the tunica mucosa and the cells lining the proventricular glands showed a positive reaction to PAS and Alcian blue stainings. In addition, the epithelial cells of the tubular and branched tubular glands showed Masson's trichrome-positive reaction. The submucosal tunic was thin in the proventricular wall. The tunica muscularis was formed by a thin inner layer of longitudinal smooth muscle fibres and a thick outer layer of circular fibres. The serosa consisted of loose connective tissue, rich in blood vessels and covered by mesothelium.