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。     

白鲟消化道形态学与组织学的初步观察

白鲟消化道具有肉食性鱼类的典型特征,其口咽腔结构既适合捕食又适合吞食与滤食水生动物。咽后消化道可分为食道、胃后行支、胃前行支、小肠、瓣肠、直肠与肛门。幽门盲囊似一致密器官,小肠与瓣肠连接处有一特殊淋巴器官,肛门两侧有腹孔。白鲟口咽腔被覆层扁平上皮,上皮内有味蕾分布。咽后消化道组织分层为粘膜(无粘膜肌层)、粘膜下层(小肠及瓣肠前部无)、肌层与外膜。粘膜上皮为单层柱状上皮,由纤毛柱状细胞、一般柱状细胞和杯状细胞组成,其间还散在有颗粒细胞和游走细胞。食道后部与胃的一般柱状细胞为分泌粘液的细胞,肠内的一般柱状细胞为吸收细胞。胃后行支及部分前行支固有膜内有消化腺,其余各部的固有膜为致密层。小肠前中部粘膜形成蜂窝状粘膜窦,无肠腺。除食道前部肌层中有横纹肌外,其余部的肌层均为平滑肌。外膜内结缔组织有的致密有的疏松,外膜表面细胞柱状或立方形或扁平。     

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。     

黄喉拟水龟消化道的组织学观察

观察黄喉拟水龟消化道的组织结构.采用常规石蜡切片和HE染色方法对黄喉拟水龟的消化道进行观察.除了口咽腔以外,消化道的管壁是由粘膜层、粘膜下层、肌肉层和外膜组成;各部分的主要区别在于粘膜层,食道和大肠的是复层柱状上皮,胃和小肠的是单层柱状上皮.黄喉拟水龟的舌桔红色,不能伸缩;食管中无食管腺,扩张性强;胃呈囊状,有大量胃腺,腔面皱襞较多;小肠较长,是消化的主要场所,表面有大量的绒毛,在绒毛中可见肠腺;大肠无绒毛,也存在皱襞.     

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。     

文县疣螈消化道和肝脏的形态学及组织学观察

利用生物显微技术对文县疣螈的消化道和肝脏进行了观察.结果 表明:文县疣螈的消化道管壁由粘膜层、粘膜下层、肌层和外膜组成.食管粘膜为复层扁平柱状上皮,胃、小肠和直肠上皮为单层柱状上皮.各段皱褶丰富.胃有发达的腺体,肠的各段无多细胞腺体分布.杯状细胞丰富,其中十二指肠最少,直肠部最多,胃的各部无杯状细胞.肝小叶分界不清,肝...     

白胸苦恶鸟消化管的组织学观察

采用石蜡切片技术对白胸苦恶鸟(Amaurornis phoenicurus)的消化道进行了组织学观察.结果表明,食管皱襞发达,黏膜上皮为复层扁平上皮,食管腺发达,颈段多于胸段,黏膜肌层为一层纵肌,厚约0.06 ～0.26 mm.肌层为一层厚约0.19～0.27mm的环肌.腺胃被覆单层柱状上皮,固有层内有单管腺和复管腺两种腺体,单管腺仅深约0.11 ～0.20 mm;复管腺厚约1.19～1.26 mm,占管壁的77.8％ ～80.4％.肌胃的类角质层发达,厚约0.16～0.24 mm.肌胃腺呈管状,与类角质层突起形成皱襞.肌层发达,由内环外纵两层平滑肌构成.肠绒毛无分支和中央乳糜管,十二指肠绒毛长而密集,空肠绒毛呈细长指状,直肠绒毛长且呈叶状.十二指肠与直肠肠绒毛内有大量致密淋巴小结,盲肠绒毛短,肠腺少.     

西藏蟾蜍消化系统组织学观察

对西藏蟾蜍的消化系统进行了组织学观察.消化道可以分为口腔、咽、食道、胃、十二指肠、回肠和直肠;肝脏和胰腺为消化腺.胃壁由黏膜层、黏膜下层、肌肉层和外膜组成.黏膜层中含有许多胃腺,但胃腺的颈部和腺体部不明显.肌肉层发达,有内环外纵两层平滑肌.小肠壁由黏膜层、黏膜下层、肌肉层和外膜组成,十二指肠的黏膜下层缺失.在黏膜层的固有膜中有管状肠腺.肝脏分为左、中、右3叶,肝小叶界限不明显.胰腺中的腺泡由腺细胞围成.     

高山倭蛙消化道结构初步观察

高山倭蛙食道粘膜上皮为复层柱状上皮,且固有膜中有丰富的复泡状腺;胃贲门部粘膜上皮无杯状细胞,PAS反应显示固有膜中有深红色颗粒分布,胃体中胃腺丰富;肠分为小肠、大肠、直肠3部分.小肠和直肠上皮中杯状细胞数量多.无尾类消化道结构与海拔高度无明显相关关系.     

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)。     

商城肥鲵消化道的解剖学观察

该文首次报道了商城肥鲵消化道各部分的形态结构、长度及其组织学结构。结果表明,除口腔外,消化道管壁由粘膜层、粘膜下层、肌层和浆膜层构成,消化道各部分的差别主要在粘膜层和肌层食道粘膜为复层柱状上皮,食完纵肌层,胃、肠粘膜上皮为单层柱状上皮,胃、肠肌层由内环外纵两层平滑肌组成。粘膜上皮的皱褶程度、腺体分布情况、肌层的相对厚度等在消化道各部分也存在差异。     

银鲳消化道形态与组织学结构特征及其消化酶活性

为了解银鲳(Pampus argenteus)消化道结构特点与其功能及食性的相关性, 采用解剖、石蜡切片、AB-PAS染色及酶活性检测技术对银鲳消化道的形态、组织结构、黏液细胞分布及消化酶活性进行研究。结果显示, 银鲳的消化道由口咽腔(舌)、食道侧囊、食道、胃及肠构成, 胃肠交界处有很多幽门盲囊。食道侧囊呈椭球形, 食道粗短, 胃呈U型, 肠有多个盘曲, 肠指数为2.03。舌上皮内有少量味蕾及较多黏液细胞。食道侧囊、食道、胃及肠均由黏膜层、黏膜下层、肌层及浆膜组成。食道侧囊内皱襞较发达, 被覆复层扁平上皮, 内含较多黏液细胞, 且以Ⅳ型为主, 皱襞顶端及侧面有内含角质刺的次级突起; 黏膜下层及肌层中有固定皱襞的骨质脚根; 侧囊内胃蛋白酶活性较高。食道内皱襞较高, 被覆复层扁平上皮, 内含较多黏液细胞, 且以Ⅳ型为主。胃内皱襞发达, 被覆单层柱状上皮, 未见黏液细胞分布; 胃腺发达, 胃内蛋白酶活性较高。肠道内褶襞多, 高度呈先下降后上升趋势, 黏液细胞密度前、中肠较高, 后肠较低, 且均以Ⅰ型为主; 肠道内胰蛋白酶、脂肪酶、淀粉酶及碱性磷酸酶活性较高。幽门盲囊组织结构与肠相似。银鲳的消化道结构特点、黏液细胞分布及消化酶活性与其功能及偏肉食的杂食性相适应。     

光唇鱼消化道的形态结构特征

采用解剖及石蜡切片显微技术,观察研究了光唇鱼消化道的形态结构特征。消化道由口咽腔、食道、肠构成。口下位、马蹄形,无颌齿,具咽齿,齿式为4/4。舌较小,前端游离,舌粘膜表层为复层鳞状上皮,有较多的杯状细胞和味蕾。食道及肠均由粘膜层、粘膜下层、肌层及外膜构成。食道内皱襞发达,粘膜层有大量杯状细胞。肠道盘曲,由前、中、后肠组成,肠长/体长为1.84±0.24;前肠管腔较大,中、后肠管腔渐变小;前、中肠皱襞及纹状缘比后肠发达;前肠及后肠杯状细胞较少,中肠杯状细胞较多。光唇鱼消化道的形态结构特征与其食性相适应。     

刀鲚幼鱼消化系统的组织形态学结构

采用光镜和扫描电镜观察长江刀鲚(Coilia nasus)幼鱼消化系统组织形态学结构。结果显示,刀鲚体长,口裂大,含有犬齿状的颌齿和尖锥状的腭齿,具有5对鳃弓,鳃耙长度明显大于鳃丝且表面附着不规则绒毛状细齿;胃呈"Y"型,胃与肠连接处具有16～21个指状环形幽门盲囊;肠为直肠,较短,比肠长为0.241±0.080;肝分为两叶,胰为独立的器官。刀鲚口咽腔为复层鳞状上皮,含有腺体、大量椭圆形黏液细胞、少量杯状细胞及味蕾;胃黏膜都为典型的单层柱状上皮,含有较多由上皮凹陷形成的胃小凹和胃腺;幽门盲囊具有20～25个丰富的褶皱,占满大部分幽门盲囊腔,黏膜层具有微绒毛;中肠黏膜上皮最发达,形成的褶皱细长且连接成网状,单层柱状上皮与复层扁平上皮交替分布。观察结果表明,刀鲚消化系统具有典型肉食性鱼类特征。     

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.     

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.     

Histological and ultrastructural specialization of the digestive tract of the intestinal air breather hoplosternum thoracatum (teleost)

The digestive tract of Hoplosternum thoracatum consists of an esophagus, gastric area, anterior digestive intestine with elaborate folds, digestive intestine with decreasing folds and thin, smooth-surfaced respiratory intestine. The upper tract has a mucoid columnar lining which is gently folded, whereas the gastric area has numerous pits opening into the tubular secretory glands. Striated muscle comprises the anterior muscularis but is replaced by inner circular and outer longitudinal smooth muscle layers in the gastric region. The digestive intestinal mucosa is elaborately folded, consisting of columnar cells with prominent brush borders. Mucosa, submucosa, circular and longitudinal muscularis and serosa layers are present throughout the tract. Goblet cells occur in both the digestive and respiratory intestine. Major changes that appear in the respiratory intestine are a drastic reduction in mucosa epithelial thickness and the penetration of an elaborate capillary bed into the epithelium. The other basic layers are not significantly reduced in thickness. The air-blood barrier consists of the thin epithelium, basement lamina and very thin capillary endothelium. Regional cellular composition and ultrastructural features are correlated with respective digestive and respiratory functions.     

The digestive tract of the amberjack Seriola dumerili, Risso: a light and scanning electron microscope study

The histology of the digestive tract of the amberjack ( Seriola dumerili , Risso) was studied using light and scanning electron microscopy. The anterior oesophagus mucosa displays primary and secondary folds lined with a stratified squamous epithelium with fingerprint-like microridges which is substituted, on the top of the oesogaster folds, by a simple columnar epithelium with short microvilli. Only primary folds are present in the stomach. The anterior portion is rich in simple tubular glands, whereas the oesogaster and the pyloric region are devoid of them. Pyloric caeca and anterior and middle intestine mucosa display the same pattern of folding. The dominant cell type is the enterocyte, which exhibits larger and thinner microvilli in the caeca than in the intestine. The columnar epithelium of the rectum is replaced, in the anal sphincter, by a stratified flattened epithelium. Goblet cells are numerous throughout the whole length of the tract with the exception of the initial part of the oesophagus, the oesogaster, the stomach and the anal sphincter. Mucosubstances have been shown to vary in the different regions of the gut: acid mucines are found in the oesophagus, pyloric stomach, caeca, intestine and rectum, whereas neutral mucosubstances dominate in the anterior portion of the stomach. The muscularis is well developed throughout the length of the tract: two layers of striated muscle at the oesophageal level; two layers of smooth muscle in the stomach wall and three at the intestinal level.