东方铃蟾消化道组织学的初步研究

采用组织学方法对东方铃蟾的消化道进行了研究。结果表明:肠分为十二指肠、空肠和大肠。消化道管壁由粘膜层、粘膜下层、肌层和浆膜层构成。食道、胃和肠均为单层柱状上皮。胃和十二指肠的粘膜皱褶最丰富。食道腺为复泡状腺,胃腺属于单管状腺,肠的各段无多细胞腺体,但空肠和大肠有丰富的杯状细胞。肌层均为平滑肌,内层环肌较厚,外侧纵肌较薄,其中大肠的外侧纵肌最发达。     

中华绒螯蟹消化道组织学及扫描电镜研究

对中华绒螯蟹成蟹消化道各段进行了光镜组织学结构的观察;应用扫描电镜技术,观察了中华绒螯蟹消化道各段黏膜上皮表面超微结构特征。结果表明：除中肠及后盲囊外,整个消化道黏膜上皮表面均有较厚的分泌物层和较发达的纤毛层。纤毛形态结构各异;以食道和后肠分布最密,胃和肠球次之。消化道各段黏膜上皮细胞表面均形成大小不一、形态各异的多级皱褶和嵴。仅中肠表面具典型微绒毛结构。各消化道段黏膜上皮表面均未见杯状细胞,上皮下基膜发达,黏膜下层明显,消化腺分布其间。整个消化道壁的肌层均为横纹肌,且排列疏松,外膜多为浆膜。     

版纳鱼螈消化道解剖学和组织学观察

对我国特有珍稀濒危两栖动物版纳鱼螈(Ichthyophis bannanicus)的消化道进行解剖和组织学观察.结果表明,版纳鱼螈消化道呈直管状,无盘曲;胃、肠分化明显,肠可分为十二指肠、空肠、大肠和直肠;黏膜上皮食管为复层柱状纤毛上皮,胃后段为单层柱状上皮,直肠为复层扁平上皮,其余均为复层柱状上皮;口咽腔黏膜含大量巨型杯状细胞,有单泡状颌间腺;食道中下段有团泡状食道腺;胃体部含大量单管状胃腺;十二指肠和空肠有单泡状肠腺,绒毛发达;口咽腔的黏膜下层不明显,食道和直肠的黏膜下层为疏松结缔组织,其余均为细密的结缔组织;肌层除口咽腔为骨骼肌外,其余均为内环外纵两层平滑肌,其中,在十二指肠和空肠的两肌层间有细密的结缔组织连接.     

花消化系统形态学及组织学的初步观察

采用活体解剖、测量及HE、AB-PAS染色等方法,对45尾体长范围11.30~28 cm花Hemibarbus maculates Bleeker的消化系统形态学、组织学特征进行了研究。结果表明,花消化系统具有以下特点:(1)消化系统包括消化道和消化腺两部分。消化道包括口咽腔、食道、肠和肛门,消化腺包括肝胰脏和胆囊,无胃。(2)口下位,吻尖而细长,口裂长/吻长雄性显著大于雌性(P0.05);口咽腔黏膜上皮为复层鳞状上皮,内有黏液分泌细胞和味蕾结构。(3)食道粗短,前段有味蕾,肌层发达且内壁有较深的纵向褶皱,黏膜层内有大量的杯状细胞、黏液分泌细胞,还有柱状上皮区域,游离面具有纹状缘。(4)肠呈S型,无肠腺,分为前肠、中肠和后肠,比肠长均值为0.98±1.29;食道粘膜下层及环肌层最厚与肠道各段有极显著差异(P0.01)。前肠、中肠和后肠黏膜皱褶数量、黏膜皱褶高度、黏膜下层厚度、杯状细胞数量显著减少(P0.05),浆膜层厚度却增加,前肠和后肠有显著差异(P0.01)。(5)食道和肠道的黏膜层发现有数量较多的颗粒细胞。(6)肝不分叶,为长条形,胆囊被肝包围;肝与胰脏不分开,胰脏弥散于肝、脾及肠管之间,比肝胰脏重(%)雄性(1.83±0.64)显著大于雌性(1.34±0.50)(P0.05)。(7)体长(L)与消化道长(Y)的关系呈线性相关:Y=1.1692L+1.2688(R2=0.653)。     

野生与养殖黄鳍鲷消化道形态组织结构

采用常规石蜡组织切片的方法对野生和养殖黄鳍鲷(Sparus latus)消化道的形态组织结构进行了比较观察。结果表明,野生和养殖黄鳍鲷的消化道存在一定差异。(1)形态学研究表明,食道粗而短,胃呈V形,分为贲门部、胃体部和幽门部,胃与肠的连接处有4条幽门盲囊,肠道在体腔内迂回两个回折。野生黄鳍鲷牙齿更为坚硬锋利,体腔中脂肪较少,消化道更为粗短。野生和养殖黄鳍鲷的肠道系数分别为0.71±0.03和0.94±0.12。(2)组织学研究表明,食道黏膜上皮由扁平细胞层和杯状细胞层组成,杯状细胞发达。胃黏膜由单层柱状上皮组成,无杯状细胞,贲门部和胃体部胃腺发达。幽门盲囊组织学特征与肠相似,上皮为柱状上皮,其中的杯状细胞少于肠。肠中,前肠杯状细胞最多,中肠次之,后肠最少。直肠杯状细胞多于肠。野生与养殖黄鳍鲷组织学的区别在于,消化道相同部位养殖鱼的杯状细胞多于野生鱼,野生鱼的肌层厚度大于养殖鱼。黄鳍鲷消化道的形态组织结构与其生活环境和食物是相关的。     

人工养殖稀有鮈鲫消化道组织学观察

采用活体解剖和显微技术对人工养殖的稀有鮈鲫消化道组织结构进行了详细观察,并描述了其形态结构。结果表明:稀有鮈鲫为杂食性无胃鱼,肠道系数0.64±0.06。消化道包括口咽腔、食道、肠和肛门。口咽腔和食道粘膜层为复层扁平上皮,内含较多杯状细胞、粘液细胞和少量味蕾;食道粗短,肌肉层发达。肠由前肠、中肠和后肠三部分组成。肠道由前到后,粘液细胞数量逐渐增多,粘膜皱褶数量逐渐减少,粘膜皱褶高度逐渐降低。     

美洲黑石斑鱼消化道的形态结构

采用解剖和光镜技术观察了美洲黑石斑鱼消化道的形态及组织学结构。消化道由口咽腔、食道、胃、肠构成。口咽腔较大,具颌齿、腭齿及犁齿;舌由基舌骨突出部分覆盖粘膜构成。食道、胃及肠均由粘膜层、粘膜下层、肌层及外膜构成。食道粘膜层绒毛分柱状上皮区及扁平上皮区,扁平上皮区表面为杯状细胞层;食道粘膜下层中有食道腺。胃呈V形,由贲门部、胃体部及幽门部组成,胃壁粘膜层上皮为单层柱状上皮,胃腺位于贲门部与胃体部的固有层中。肠细长,呈S型,由前、中、后肠构成,粘膜层向肠腔突起形成肠绒毛,粘膜上皮为单层柱状上皮,上皮游离面有微绒毛密集排列而成的纹状缘,上皮中含有杯状细胞,且杯状细胞的数量从前向后呈递减趋势;肠长/体长约为1.6。胃与小肠相接处有3对指状幽门盲囊,幽门盲囊的组织学结构与肠相同。     

梭鱼消化系统的组织学研究

采用石蜡切片等组织学研究手段,以生活于海水和咸淡水中的梭鱼Liza haematocheila作为实验材料,对其消化系统的组织学结构进行了观察.比较了消化道各部分粘膜褶皱的高低、多少、疏密程度,粘膜上皮细胞的类型,杯状细胞在数量上的变化以及消化道肌层的肌肉组织类型和肌细胞的排列方式.结果显示:咸淡水梭鱼的肠道中杯状细胞的数量多于海水梭鱼,食道是横纹肌,但其它消化道均为平滑肌.肝脏中肝小叶不明显,肝细胞索明显.胰腺呈弥散状分布,其中有胰岛存在.     

中华蟾蜍与黑斑蛙消化道黏液细胞的观察

目的：探索两栖类动物消化道黏液细胞的类型与分布规律。方法：利用阿利新蓝与过碘酸雪夫试剂染色法对中华蟾蜍（Bufo bufo gargazizans）、黑斑蛙（Rana nigromaculata）消化道黏液细胞进行石蜡切片和染色。结果与结论：黏液细胞表现为4个类型：Ⅰ型玫瑰红色;Ⅱ型蓝绿色;Ⅲ型紫红色;Ⅳ型蓝紫色。两种动物食管黏膜上皮中黏液细胞主要是杯状细胞,其中中华蟾蜍的黏液细胞主要为Ⅱ型和Ⅳ型细胞,黑斑蛙的黏液细胞主要Ⅲ型细胞。胃体柱状黏膜上皮细胞与胃腺颈细胞主要为Ⅰ型和Ⅲ型细胞,黏原颗粒主要集中在细胞的核上区。胃腺浅部有成团分布并着色较浅的黏液细胞,其中黑斑蛙胃腺黏液细胞主要为Ⅰ型和Ⅲ型细胞,中华蟾蜍胃腺黏液细胞主要为Ⅲ型和Ⅳ型细胞。小肠杯状细胞主要为Ⅲ型和Ⅳ型细胞。大肠杯状细胞主要为Ⅱ型和Ⅳ型细胞。     

香鱼消化道及肝脏的形态结构特征

采用解剖及石蜡切片显微技术观察了香鱼消化道及肝脏的组织学结构。香鱼消化道由口咽腔、食道、胃及肠构成。口咽腔大且狭长,其底壁前部有一对粘膜褶,两颌边缘着生宽扁梳状齿,腭骨及舌骨具齿,犁骨无齿;舌由基舌骨突出部分覆盖粘膜构成,舌粘膜上皮为复层扁平上皮,含有较多的杯状细胞和味蕾。食道、胃及肠均由粘膜层、粘膜下层、肌层及外膜构成。食道粘膜层上皮为复层扁平上皮,杯状细胞发达。胃呈V形,由贲门部、胃体部及幽门部组成,胃壁粘膜上皮为单层柱状上皮,贲门部与胃体部的固有层中有胃腺。肠较短,由前、中、后肠构成,肠壁粘膜上皮为单层柱状上皮,其游离面具微绒毛;上皮细胞间有杯状细胞。幽门盲囊有350～400条,其组织学结构与肠相同。肝脏单叶,外被浆膜;肝细胞形态不规则,肝小叶界限不明显。     

马铁菊头蝠消化系统的组织学观察

应用石蜡常规切片、HE染色,对马铁菊头蝠消化系统各器官的组织结构进行了观察.结果 表明:食管粘膜上皮为复层扁平上皮,轻微角质化,前、中、后段的上皮结构没有显著差异,食管腺在前段较多,中、后段较少.胃固有层含有大量的管状腺.小肠粘膜表面有许多环形皱襞,在十二指肠上段粘膜下层分布有十二指肠腺.大肠粘膜表面光滑,无绒毛,在粘膜下层的结缔组织中有小动脉、静脉和淋巴管.肝内结缔组织多,肝小叶分界较明显,肝血窦发达.胰的小叶间分界不明显.     

Histological and ultrastructural study of the digestive tract of rice field eel, Monopterus albus

The histological characteristics of the digestive tract and the ultrastructure of mucosal cells of the stomach and intestine of rice field eel, Monopterus albus, are described to provide a basis for future studies on its digestive physiology. The digestive tract of the rice field eel is a long and coiled tube composed of four layers: mucosa, lamina propria‐submucosa, muscularis and serosa. The pharynx and oesophagus mucosa is lined with a stratified epithelium. The stomach includes the cardiac and pyloric portions and the fundus. Many gastric pits are formed by invaginations of the mucosal layer and tubular gastric glands formed by the columnar cells in the fundus. The intestine is separated from the stomach by a loop valve and divided into a proximal portion and a distal portion. The proximal intestinal epithelium consists of columnar cells with microvilli towards the lumen and goblet cells. The enterocytes are joined at the apical surface by the junctional complex, including the evident desmosomas. Numerous lysosomes and some vesicles are evident in the upper cytoplasm of the cells, and a moderate amount of endoplasmic reticulum and lysosomes are scattered in the supranuclear cytoplasm. The epithelium becomes progressively thicker and the folds containing large numbers of goblet cells are fewer and shorter in the distal portion of the intestine. At the ultrastuctural level, the columnar cells of the tubular gastric glands have numerous clear vacuoles and channels. A moderate amount of pepsinogen granules are present in the stomach. The enterocytes of the intestinal mucosa display a moderate amount of endoplasmic reticulum and lysosomes, and long and regular microvilli.     

A study of the anatomy, histology and ultrastructure of the digestive tract of Orthrias angorae Steindachner, 1897

The anatomy, histology and ultrastructure of the digestive tract of Orthrias angorae (Steindachner, 1897) were investigated using light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The histological structure consists of four layers: mucosa, submucosa, muscularis and serosa. The esophageal mucosa consists of undifferentiated basal epithelial cells, mucous cells and surface epithelial cells. It was observed that the J-shaped stomach had a meshwork of folds in the cardiac region, and longitudinal folds in the fundic and pyloric regions. A single layer of columnar cells, PAS positive only in their apical portions, forms the epithelium. The convoluted tube-shape intestine is lined by simple columnar epithelial cells, which have microvilli at the apical surface. The wall of the esophagus and stomach are thicker than that of the intestine because of the thick muscle layer. There were numerous goblet cells in the intestine. There were numerous gastric glands in the submucosa layer ofthe cardiac stomach, but none were present in the pyloric region of the stomach. There were no pyloric caeca between the stomach and intestine. The enterocytes with microvilli contained rough endoplasmic reticulum, ribosomes and rounded bodies, and the gastric cells contained a well-developed Golgi apparatus.     

Morphological and histochemical characterisation of the mucosa of the digestive tract in matrinxã Brycon amazonicus (Teleostei: Characiformes)

This study describes anatomical, histological and histochemical features of the digestive tract mucosal layer of the matrinxã Brycon amazonicus, an omnivorous freshwater fish endemic from the Amazon basin. This species presents short thick oesophagus with longitudinal folds, that allow the passage of large food items. The mucosa is lined with a stratified secretory epithelium rich in goblet cells that secrete neutral and acid mucins. The two mucin types provide different viscosity in anterior and posterior oesophagus related to the protective and lubricant functions, respectively. The stomach is a highly distensible Y-shaped saccular organ. Here, it is proposed that this anatomical shape plays an essential role in food storage when food availability is abundant. The stomach mucosa is composed of epithelial cells with intense neutral mucin secretion to protects against gastric juice. The intestine is slightly coiled and presents internally a complex pattern of transversal folds that increases the absorption surface and the retention time of food. Goblet cells in the intestine secrete acid and neutral mucins that lubricate the epithelium and aid in the digestive processes. In the rectum, an increase in goblet cells population occurs that may be related to better lubrication.     

暗腹雪鸡食管和胃的形态学及组织学观察

为了解暗腹雪鸡(Tetraogallus himalayensis)食管和胃的形态及组织结构特征,利用生物显微技术对暗腹雪鸡的食管和胃进行了观察.结果表明,暗腹雪鸡嗉囊发达.食管壁由黏膜层、黏膜下层、肌层和外膜组成,黏膜层较厚,黏膜上皮为复层扁平上皮,固有膜内食管腺丰富,由腺细胞围成的腺管直接开口于黏膜上皮,食管肌层发达,由内环、外纵平滑肌组成.胃壁由黏膜层、肌层和外膜组成,胃的黏膜下层不发达或缺无,胃肌层的排列则为内纵外环.表明暗腹雪鸡食管和胃的结构可能与其消化功能及其生境密切相关.     

Scanning electron microscopy of goldfish, Carassius auratus, intestinal mucosa

Scanning electron microscopy was used to examine the intestinal bulb and the caudal portion of the intestine proper of the goldfish, Carassius auratus . The observations made correlated well with previous light microscope studies by other investigators. The mucosal surface of the entire intestine of the goldfish is thrown up into folds, which are oriented along the long axis of the digestive tract in the intestinal bulb, but run more or less transversely in the caudal intestine. Tops of the folds were observed to be rounded or flattened, and the folds themselves formed wavy or zigzagging patterns in the mucosal surface. Numerous mucus-secreting goblet cells were seen, which were apparently more numerous or more active in the caudal intestine than in the intestinal bulb. The goblet cells are not uniformly distributed throughout the mucosa: they are more evident on the sides of the folds, although occasionally they appear to be located in clusters on the tips.
The goblet cells were observed to contain varying amounts of mucous material, and/or to be of different sizes. Although no histochemical tests were performed, the possibility that digestive enzymes known to be present in the intestine may be elaborated by the goblet cells was considered, based on their variable appearance.     

Histochemical and ultrastructural study of the digestive tract of the tortoise Testudo graeca (Testudines)

The digestive tract of the tortoise Testudo graeca (Testudines) was investigated by means of light and electron microscopy. The esophagus of T. graeca was lined by two types of epithelium: non-keratinized stratified squamous in the upper portion and stratified columnar in the lower. The lamina propria of the esophagus contained tubular or tubuloacinar glands. The mucosa of the stomach showed similar characteristics to those of other reptiles. The small intestine exhibited longitudinal folds lined by absorptive and goblet cells. The large intestine was lined by columnar mucous cells. Within the lamina propria of the large intestine, masses of 10–15 epithelial cells connecting with the surface epithelium by means of slender cytoplasmic processes were observed. A battery of six lectins (Con-A, PNA, WGA, DBA, SBA, and LTA) was used to identify the epithelial mucins. WGA and DBA reacted with all types of mucous cells throughout the alimentary canal. PNA was only unreactive in the intestine, LTA in the esophagus, and SBA in the large intestine. These results indicate a similar lectin-binding pattern throughout the gut of T. graeca.     

Peroxidase activity in the epithelium of the digestive tract of the bullfrog, Rana catesbeiana

Peroxidase activity was examined cytochemically in the mucosal epithelium along the length of the digestive tract from the esophagus through the large intestine during the development of the bullfrog, Rana catesbeiana. In the tadpole of this species, cells with peroxidase activity were found abundantly in the esophagus, stomach, and large intestine; and the types of such cells differed according to the region: ciliated cells and mucous cells in the esophagus; ciliated cells in the stomach; and brush cells, absorptive cells, and goblet cells in the large intestine, respectively. After metamorphosis, however, peroxidase activity was observed exclusively in absorptive cells and goblet cells in the large intestine. Peroxidase activity was commonly demonstrated in apical vesicles or granules, to some degree in rough endoplasmic reticulum, and in some elements of the Golgi apparatus. Furthermore, reaction product was also found in mucus covering the luminal surface of such epithelial cells. These findings indicate that peroxidase-positive cells, which may have the ability to synthesize peroxidase as a secretory product, were distributed mainly in three regions of the digestive tract in tadpoles (esophagus, stomach, and large intestine), but were centered in one specific region, the large intestine, after metamorphosis. Concomitantly, the variety of types of peroxidase-positive cells decreased during metamorphosis. Our results indicate that some of the peroxidase in the digestive tract may have a secretory origin and may play a role in the defense against microorganisms.