The microscopic anatomy of the oesophagus, stomach and intestine of the channel catfish, Ictalurus punctatus

An anatomical study of the digestive tract of the channel catfish revealed that the oesophageal mucosa was longitudinally folded and that secondary folds were occasionally located on the primary longitudinal folds. The infoldings were more numerous near the stomach. The stratified squamous epithelium covering the folds was made up of a basal layer, large mucous cells and simple squamous cells on the surface. The epithelium on the side of the folds consisted primarily of mucous secreting cells. Taste buds were observed between mucous cells on the apical portion of the oesophageal folds and were more prevalent in the cranial part of the oesophagus. The remaining layers of the oesophagus were: a lamina propria-submucosa, tunica muscularis and adventitia or serosa.
The J-shaped stomach had two regions: a large sac-shaped region containing gastric glands and a smaller, nonglandular pyloric region. The large rugae of the stomach became gradually smaller near the pylorus. There was a well developed pyloric sphincter. The mucosa included a simple columnar epithelium, a lamina propria and adventitia or serosa.
The intestine could be differentiated into a thick ascending segment, a descending segment, a thin convoluted segment and a thicker terminal segment, the rectum. Many mucosal folds containing branched villi characterized the ascending segment of the intestine. The descending and convoluted segments contained fewer folds with shorter and less-branching villi and were smaller in diameter and thinner walled. Descending and convoluted segments were also mildly convoluted and accounted for 80% of the total length of the intestine. An intestinal valve with a sphincter marked the beginning of the rectum. There was an approximately four-fold increase in the thickness of the tunica muscularis of the terminal segment of the intestine.     

长鳍篮子鱼消化道黏膜上皮的扫描电镜观察

采用扫描电镜观察了长鳍篮子鱼(Siganus canaliculatus)消化道黏膜上皮表面细微的结构特征。结果显示,长鳍篮子鱼食道黏膜为纵行黏膜褶皱,在褶皱上形成"V"字型次级褶皱,黏膜上皮表面具有许多分泌孔及较多腺体导管的开口,上皮细胞扁平,似鳞片状,连接紧密。胃黏膜褶皱呈绳状纵向排列,黏膜上皮表面有许多沟回,细胞之间有较多的胃小凹,在上皮表面可见有乳头状突起,未见有微绒毛;上皮细胞为五边形或六边形,无细胞间隙。肠黏膜分布着密集排列的肠绒毛,绒毛呈拇指状或扁平状,黏膜上皮表面呈脑回状,分布有许多分泌颗粒,细胞游离面分布着丰富的微绒毛,细胞为多边形、圆形、不规则形,有细胞间隙。幽门盲囊黏膜上皮的结构与肠道相似。本文探讨了黏膜上皮结构与功能的关系。     

The phenomenon of hyperproduction and in vivo shedding of excess epithelial layers of intestinal villi

The native mucosa of enterobioptates of different animal species and men was examined with the use of binocular magnifier in combination with microscopic studies of serial sections of some intestinal villi isolated from mucous membrane. Areas with masses of fully or partially rejected excessive epithelial structures (long folds, plates, tubules) were revealed. The phenomenon under study is one of the sources of the epithelium in the mucous layer on the luminal surface of the small intestine.     

Morphology and fine structure of the gravid uterus of three hymenolepidid tapeworm species (Platyhelminthes: Cestoda)

Summary

The ultrastructure of the uterus in gravid proglottids of Hymenolepis citelli, Vampirolepis nana and Vampirolepis microstoma was examined using transmission and scanning electron microscopy. The cellular and subcellular structures were similar in all three species, consisting basically of a syncytial layer attached to a basal extracellular matrix. All nuclei were juxtaluminal and each contained a single large centrally located nucleolus and prominent masses of central and peripheral heterochromatin. The cytoplasm showed evidence suggesting a high level of protein synthesis and secretion. It consisted primarily of granular endoplasmic reticulum with moderately dilated cisternae; most cisternae were completely filled with an electron-lucent flocculent material, but others contained electrondense granules. Free ribosomes and mitochondria were also present. The apical plasma membrane and a small amount of enclosed cytoplasm were folded into long microlamellae that extended into the uterine lumen. Larger epithelial folds and villi consisting of folded portions of the entire epithelium projected into the uterine lumen. The uterine epithelium along with its basul extracellular matrix and underlying cellular parenchyma were folded into the lumen at several points, forming epitheliomesenchymal folds and villi that closely apposed many of the eggs.     

Some morphological and histochemical studies on the intestinal tract of the Brazilian sloth (Bradypus tridactylus)

The intestinal of the 3-toed sloth, Bradypus tridactylus, was studied macroscopically, with light microscope and with histochemical methods for mucosubstances. Macroscopically, the inner surface of the duodenum shows longitudinal and circular folds. There is no caecum, nor appendix. The large intestine consists of a short colon and a large rectal pouch, which has a thick wall. The mucosa of the small intestine has long leaf-shaped villi covered with columnar epithelium having a well developed striated border, and the goblet cells are scattered among the columnar cells. An association between neutral and acidic mucosubstances was detected in the goblet cells. The duodenal (Brunner's) glands are confined exclusively in the lamina propria of the duodenum. No Paneth cells were observed in the crypt lining. Argyrophil and argentaffin cells were found in the entire length of the intestine. The large intestine does not possess villi, but many goblet cells were observed in its mucosa.     

The effect of hydroxyurea on ciliogenesis in ciliary epithelium of the mollusk Lymnaea stagnalis

Electron-microscopy study of the ciliary epithelium structure of the mollusk Lymnaea stagnalis was carried out under the action of hydroxyurea. By the method of radioautography, a high proliferative activity of the ciliary epithelium was established as the norm; a cluster distribution of cells, including the label, was noted. The presence of hydroxyurea in the mollusk organism was shown to inhibit proliferation. Scanning electron microscopy of the molluskan foot surface revealed clusters of nonciliated cells and of cells with short villi in control epithelial folds. Under hydroxyurea treatment for 24 h, such sites disappeared completely and ciliary epithelium looked uniform and was composed of cells with long cilia. By transmission electron microscopy, it was established that hydroxyurea did not affect the formation of the basal body and course of ciliogenesis. It has been suggested that hydroxyurea not only inhibits proliferative activity of epithelial cells, but also induces differentiation of unciliated into the ciliated cells.     

Peyer’s Patches and the Follicle-Associated Epithelium in Diarrheic Calves

Twelve 2–5-week-old calves affected with a spontaneous intestinal disorder were examined; 8 had diarrhea and 4 were convalescents. In all the affected calves the “pseudovilli” (syn. domes or lymphoid villi) over Peyer’s patches seemed atrophic and appeared enclosed within the mucosa, owing to fusion of ordinary villi with “pseudovilli”. Morphometric examination showed a decrease of lymphoid follicle length in the affected calves as compared with controls (P < 0.01). Convalescents showed longer follicles than diarrheic calves (P<0.05). Often cytoplasmic acid phosphatase of the follicle-associated epithelium (FAE) in affected calves did not show the marked basal-apical decrease along “pseudovillus”, typical of the controls. Scanning electron microscopy revealed sparse development of concentric folds in the luminal plasma membrane of the enclosed FAE, contrasting with their abundance in the normal FAE. Transmission electron microscopy showed that the “pseudovilli” had increased numbers of ordinary villous epithelial cells. Affinity of chlamydia for FAE was shown. It is suggested that the sparse occurrence of surface folds in the FAE and the change in acid phosphatase distribution indicate diminished endocytosis of antigenic material, probably resulting from the enclosure of “pseudovilli”. The atrophy of lymphoid follicles may be another expression of the probable decreased contact with the intestinal contents.     

黑麂肝、小肠和大肠的组织学结构及Ghrelin的分布

研究了成年雌性黑麂(Muntiacus crinifrons)的肝、小肠和大肠的组织学结构及Ghrelin的分布。采用H.E染色法观察组织学结构,免疫组化PV-9000两步法并结合DAB显色技术确定Ghrelin的分布。结果表明,黑麂的肝组织分为被膜、肝小叶、肝中央静脉、门管区等结构。被膜为浆膜结构,肝小叶不明显。肝细胞以中央静脉为中心,呈放射状排列。肝血窦的形状不规则。肠黏膜上皮为单层柱状上皮,小肠、盲肠和结肠的黏膜肌层很薄,管壁皱襞与肠绒毛等形态在消化道各部也存在差异。免疫组化结果显示肝细胞中有Ghrelin阳性细胞的表达;在肠道,免疫阳性细胞在十二指肠、空肠、回肠、盲肠和直肠的黏膜、黏膜下层和肌层均有分布,尤其在肠绒毛上皮和黏膜下层分布较多。黑麂肝、小肠和大肠结构与哺乳动物基本相似,但无十二指肠腺;Ghrelin阳性细胞在肝、小肠和大肠均有分布,这表明Ghrelin可能对消化有一定的调节作用。     

青海沙蜥消化道组织结构及嗜银细胞研究

为揭示青海沙蜥消化系统的组织结构,探索其高海拔适应的组织学基础,应用解剖学与石蜡切片、H.E染色和Grimelius银染法对青海沙蜥消化道组织结构和嗜银细胞进行研究。结果显示:青海沙蜥的消化道管壁结构分为4层,从内到外依次是粘膜层、粘膜下层、肌层和浆膜。消化道各段的长度和壁厚均存在显著差异,其中小肠最长,胃幽门部的管壁最厚。粘膜皱襞和绒毛的分布也存在差异,空肠部位的小肠绒毛数量最多,其次是十二指肠和回肠。嗜银细胞形状多样,广泛分布在消化道各段的黏膜上皮基部和黏膜上皮之间。胃体是嗜银细胞分布密度最高的部位,其次是贲门,回肠最低。与栖息在低海拔的有鳞类相比,青海沙蜥为适应高海拔环境,小肠的相对长度变长,胃体部嗜银细胞增多。     

Comparative development of ruminant placentomes

Histological examination of placentomes from cows, sheep, deer, and several antelope species revealed a common pattern of development of the utero-placental junction. Chorionic membrane in contact with the uterine caruncles developed "milky patches" composed of a thick trophoblastic epithelium and multiple allantoic blood vessels, while caruncles formed simultaneously a network of crypts. The milky patches formed chorioallantoic villi that penetrated into the caruncular crypts usually simultaneously with both the villi and crypt formation but partial delay between the villi/crypt formation and penetration had no apparent detrimental effect on the fetus. The villi penetrated into caruncles in a row until they reached the dense basal layer separating caruncular mass from adjacent glandular endometrium. Further placentome growth continued by increasing the length, diameter, branching, and surface corrugation of the villi. Placentomes in different stages of development coexisted at different locations within the uterus throughout the pregnancy. During placental release after parturition, entire villi or only the villi mainstems can pull out of the maternal crypts, or the entire placentome mass can separate from the uterine wall. The remaining maternal portions of the placentomes are destroyed and sloughed down to the basal layer, leaving only a narrow band of the caruncular tissue for the regeneration of caruncles. The bare, wrinkled caruncular surface is then covered with a new epithelium and ultimately becomes smooth.     

Morphological aspect of voice disturbances of aged persons coexisting hypopharynx cancer

The voice quality in prebysphonia is conditioned by morphological changes in the vocal folds mucosa. The studies including light microscopy and transmission electron microscopy (TEM) revealed changes within the basal membrane epithelium and the stroma of the vocal folds mucosa. Age-related changes in thickness of the epithelium and direction of the basal membrane, increased number of collagenous fibres (C) and fibroblasts and chronic inflammatory process in the stroma were found. Vacuolated and keratinised epithelial cells, enlarged extracellular spaces and numerous blood vessels confirm the edematous form of prebysphonia. Thinned epithelium with signs of hyalinization, inflammatory infiltrations in the stroma with numerous collagenous fibres and small number of blood vessels indicate atrophy of the vocal folds mucosa. Edematous and atrophic changes in the vocal folds mucosa are most frequently reported form of prebysphonia.     

Comparative study of the olfactory epithelium of the three-spined stickleback (Gasterosteus aculeatus) and the nine-spined stickleback (Pungitius pungitius)

Summary The olfactory epithelium of the three-spined stickleback (Gasterosteus aculeatus) and the nine-spined stickleback (Pungitius pungitius) has been studied with a conventional histochemical and a novel immunological staining technique. In both species, the sensory epithelium is arranged in folds separated by non-sensory epithelial tissue. In the nine-spined stickleback, intrinsic folds consisting of non-sensory cells are found in the apical part of the sensory epithelium where they divide the surface of the sensory epithelium into small islets. These non-sensory cells are non-ciliated, flattened and piled on top of each other; they contain numerous electron-translucent vesicles. The intrinsic folds are absent from the sensory epithelium of the three-spined stickleback. In both species, axons of receptor cells form a layer of fibers in the sensory epithelium immediately above the basal cells. In the three-spined stickleback, thick branches of the olfactory nerve are frequently found in this layer. These branches are only occasionally observed in the sensory epithelium of the nine-spined stickleback. Thus, the three-spined stickleback and the nine-spined stickleback show considerable differences in the organization of the sensory regions of the olfactory epithelium.     

Comparative gastrointestinal morphology of three small mammalian insectivores: Acomys spinosissimus (Rodentia), Crocidura cyanea (Eulipotyphla), and Amblysomus hottentotus (Afrosoricida)

The gastrointestinal morphology was investigated in three mammalian insectivorous species, namely Acomys spinosissimus, Crocidura cyanea, and Amblysomus hottentotus. The aim of the study was to provide a comprehensive morphological comparison between the different species and to explore whether anatomical gastrointestinal adaptations are associated with the insectivorous diet of these species. The shape, proportional length, and proportional surface areas of the different gastrointestinal regions were recorded and compared in the three insectivores. Hematoxylin and Eosin (H&E) and Alcian Blue/Periodic Acid Schiff (AB/PAS) were used for morphological assessment. In all three species, the stomach was simple and uncompartmentalized. The internal aspect of the stomach in A. spinosissimus was hemi‐glandular, containing stratified squamous epithelium in the fundus, with glandular epithelium in the body and pyloric region. However, C. cyanea and A. hottentotus had wholly glandular stomachs. Paneth cells were not observed in the intestinal tracts of C. cyanea and A. hottentotus. Acomys spinosissimus was the only species studied that had a cecum. The proximal colonic region of A. spinosissimus had V‐shaped mucosal folds. Histologically, C. cyanea had villi throughout the entire gastrointestinal tract (GIT), whereas for A. hottentotus villi were not present in the most distal gastrointestinal regions. In both C. cyanea and A. hottentotus, longitudinal mucosal folds were present in the distal part of the colon. The GITs of C. cyanea and A. hottentotus showed little morphological differentiation namely, a simple, glandular stomach and the lack of a cecum. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc.     

华鲮泌尿系统组织学的初步观察

2004年3月至9月采用常规组织学方法对华鲮泌尿系统作了研究,结果表明：华鲮泌尿系统包括中肾、输尿管、膀胱。中肾由肾小体和肾小管组成,无皮质、髓质之分,有肾小体聚集现象;肾小管可分为颈段、第一近曲小管、第二近曲小管、远曲小管、集合管。肾中散布有大量淋巴髓样组织,还有甲状腺滤泡和斯坦尼氏小体,显然华鲮的肾脏是一个具有多种生理功能的复合器官。输尿管位于两肾叶腹侧,其上皮为似复层,缺黏膜下层,无纵肌,外膜甚薄。左右输尿管在后端合并,稍微扩大,形成膀胱,膀胱内壁具有发达的绒毛,绒毛表面为变移上皮。     

Morphogenesis of intestinal villi. I. Scanning electron microscopy of the duodenal epithelium of the developing chick embryo

Development of villi in the duodenum of the chick was studied in stages ranging from 11 days of incubation to one week after hatching. Formation of definitive villi is preceded by development of a set of previllous ridges that run lengthwise along the duodenum. The first set of 16 previllous ridges (Set I) is complete by about 13 days of incubation; all ridges in the set are fairly uniform and proceed through their subsequent development in synchrony. Previllous ridges in Set I fold into a highly regular zigzag pattern between 14 and 16 days of incubation. Definitive villi develop from Set I ridges beginning at about 17 days when populations of distinct cells appear on the crests of the ridges between angles in the zigzag folds. Cells in these populations lack the rounded appearance of cells seen in earlier stages; their apical surfaces are densely covered with microvilli. A second set of villi (Set II) develops at about 16 days of incubation when about 16 rows of tongue-like flaps erupt between the previllous ridges of Set I. At hatching, Set II villi are still smaller than villi of Set I; this distinction disappears by about the fourth day after hatching. The significance of the morphological changes in epithelial cells is discussed in terms of several hypotheses bearing on the mechanisms of villus formation.     

Status of the mucous membrane of the jejunum of the rat after desympathization

Desympathization of the rat jejunum has been performed by means of periarterial sympathectomy of the cranial mesenteric artery. In total preparations of the jejunum wall, by means of water-aldehyde method, catecholamines have been revealed for controlling desympathization effectiveness. Signs of reinnervation appear in 180 days after the operation. In paraffin sections, stained by general histological methods, morphometric analysis of the most important parameters of the mucous membrane is performed (height of the villi, depth of the crypts, villus/crypt index, height of the epithelium, amount of goblet cells and interepithelial lymphocytes) Height of the villi and villus/crypt index increase in 1, 3 and 14 days, while in 7 days after the operation depth of the crypts increases, and the index mentioned decreases. Height of epithelium in the villi decreases in 14, 30 and 90 days. In 3-30 days after the operation amount of interepithelial lymphocytes increases.     

Immunofluorescence study of the extracellular matrix of the human placenta

Distribution of collagen types I, III, IV, V and fibronectin in human placental villi has been studied by indirect immunofluorescence. During 9-12 weeks of pregnancy the extracellular matrix of villi represents a network of filaments organized in bundles and aggregates that contain collagen types I and III and finer filaments of collagen types IV and V. Collagen type IV is regularly detected in basal membrane of capillaries and particularly in villous epithelium, collagen type V and fibronectin are occasionally detected there. Marked immunofluorescent reaction on collagen types IV and V and fibronectin, and weak reaction on collagen type III is observed in cellular islets around cytotrophoblasts. In the fetus born in term placental villi have uniform immunofluorescence in thick basal membranes of fetal capillaries and of chorionic epithelium. The immunofluorescent reaction specific for all collagen types is uniform in villous stroma. Distribution of different collagen types and fibronectin, including the unusual localization of membrane collagen type IV, in villous stroma and cellular islets of early and mature placenta is discussed.     

Structuro-functional changes in the placenta as a result of exposure to atmospheric pollutants

Under the influence of atmospheric pollutions certain structural-functional changes take place in placenta: terminal villi per stipulated square unite, villi with desquamated epithelium, with dilated vessels, with deposition of fibrinoid masses, with plasmodial buds increase in number; section area occupied by epithelial layer decreases; RNA concentration and histoenzymatic activity change in the latter.     

Comparative macroscopic and microscopic anatomical observations on pyloric ceca in some bony fish

The authors report the variable number of pyloric caeca of some species of fish and describe their macroanatomy. They also describe and compare the microanatomy of pyloric caeca in three species; in particular they point out the thickness of tunica muscularis, the shape and length of villi which protrude into the lumen and the variable number of goblet cells. The tunica muscularis is very strong in Uranoscopus and consists of three strata: external and inner longitudinal strata, middle circular stratum. The tunica muscularis is less thick in Diplodus and in Scorpaena. The lamina propria and epithelium form villi which protrude into the lumen. They are covered with columnar epithelium and goblet cells which are more numerous in Uranoscopus and Scorpaena and less numerous in Diplodus. At last the authors describe in pyloric caeca of Scorpaena the presence of a network which engages all the lumen; it consists of connective tissue septa which directly derive from the lamina propria and is covered with the same columnar epithelium and goblet cells.