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1.
用光镜和电镜观察了乌梢蛇胃上皮的组织结构,结果表明,1胃表面上皮均为单层柱状上皮,上皮细胞上部充满电子密度较高的椭圆形或杆状黏液颗粒,PAS反应呈强阳性;2胃体及幽门区上皮分别内陷形成单管状的胃底腺和幽门腺,无贲门腺;③胃底腺腺管分颈部和颈下部,颈部上皮细胞充满电子密度较低的近圆形的黏液颗粒,PAS反应呈强阳性,颈下部上皮细胞均分泌酶原颗粒,PAS反应呈阴性;④幽门腺细胞中亦充满电子密度较低、近圆形的黏液颗粒,PAS反应呈强阳性;⑤胃腺上皮细胞之间和腺细胞基部有不同类型的内分泌细胞分布.本文认为,乌梢蛇胃的消化能力较弱,其胃的进化在爬行动物中处于较低等的地位.  相似文献   

2.
乌梢蛇胃上皮的组织学研究   总被引:2,自引:0,他引:2  
用光镜和电镜观察了乌梢蛇胃上皮的组织结构。结果表明,①胃表面上皮均为单层柱状上皮,上皮细胞上部充满电子密度较高的椭圆形或杆状黏液颗粒,PAS反应呈强阳性;②胃体及幽门区上皮分别内隐形成单管状的胃底腺和幽门腺,无贲门腺;③胃底腺腺管分颈部和颈下部,颈部上皮细胞充满电子密度较低的近圆形的黏液颗粒,PAS反应呈强阳性,颈下部上皮细胞均分泌酶原颗粒,PAS反应呈阴性;④幽门腺细胞中亦充满电子密度较低、近圆形的黏液颗粒,PAS反应呈强阳性;⑤胃腺上皮细胞之间和腺细胞基部有不同类型的内分泌细胞分布。本文认为,乌梢蛇胃的消化能力较弱,其胃的进化在爬行动物中处于较低等的地位。  相似文献   

3.
美洲黑石斑鱼消化道的形态结构   总被引:2,自引:0,他引:2  
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。  相似文献   

4.
小熊猫胃的解剖和组织结构研究   总被引:5,自引:1,他引:4  
《四川动物》2001,20(4):214-216
小熊猫的胃属单室腺型胃,它以角切迹为界,可分为胃底部和幽门部两部分.胃壁由粘膜、粘膜下层、肌层和浆膜四层组成.四上皮为单层柱状上皮,具有分泌粘液的功能.胃腺有贲门腺、胃底腺、幽门腺三种,但贲门腺不发达.主细胞、壁细胞和粘液细胞的数量与分布呈现规律性变化.肌层发达,特别是内环行肌发达.并与大熊猫胃的结构作了比较.  相似文献   

5.
米志平  杨智 《四川动物》2001,20(4):214-216
小熊猫的胃属单室腺型胃,它以角切迹为界,可分为胃底部和幽门部两部分。胃壁由粘膜、粘膜下层、肌层和浆膜四层组成。四上皮为单层柱状上皮,具有分泌粘液的功能。胃腺有贲门腺、胃底腺、幽门腺三种,但贲门腺不发达。主细胞、壁细胞和粘液细胞的数量与分布呈现规律性变化。肌层发达,特别是内环行肌发达。并与大熊猫胃的结构作了比较。  相似文献   

6.
扬子鳄(Alligator sinensis)的小胃是在胃幽门部与十二指肠的交接处由胃幽门括约肌和十二指肠括约肌突入管腔形成的一个小腔,其生理功能一直不清楚。本文采用组织化学、电子显微镜和免疫组织化学技术对扬子鳄小胃黏膜的组织化学成分、细胞超微结构及细胞类型进行了较全面的研究。小胃黏膜上皮PAS反应呈强阳性,AB染色呈弱阳性,主要分泌中性糖蛋白和少量的含硫酸性糖蛋白。电子显微镜下,扬子鳄小胃黏膜上皮主要由表面黏液细胞组成,偶见内分泌细胞。小胃腺部则70%-90%为内分泌细胞,其余为少量的腺黏液细胞和泌酸胃酶细胞。应用7种胃肠激素的抗血清在小胃黏膜中检测出了5-羟色胺(5-HT)、胃泌素(Gas)、胰高血糖素(Glu)、生长抑素(SS)、P-物质(SP)和血管活性肠肽(VIP)细胞,以Glu细胞密度最高,VIP细胞密度最低。未检测到胰多肽(PP)细胞。本研究结果表明,从组织化学成分和细胞类型看,扬子鳄的小胃与胃同源;从细胞超微结构和内分泌细胞所占百分比例看,扬子鳄的小胃已出现了明显的特化,泌酸胃酶细胞中未见泌酸小管,可能没有泌酸功能。内分泌细胞含量丰富,可能在调节胃肠道功能中发挥重要作用[动物学报54(6):1044—1050,2008]。  相似文献   

7.
金丝猴食管和胃连接部的组织学研究   总被引:1,自引:0,他引:1  
本文研究了金丝猴食管和胃连接处的组织结构。金丝猴的食管粘膜为典型的复民鳞状上皮,食管末端含有粘膜腺,粘膜表面有轻微的角质化。管壁外纵肌层有少量的横纹肌。与胃粘膜的连接均位于胃的贲门部以内,两种上皮的连接是突然的,不存在过渡。 贲门腺为少量的分枝管状腺,短而直,由粘膜细胞构成,对PAS染色呈阳性反应。  相似文献   

8.
应用ABC免疫组织化学方法,对棕色田鼠胃肠道内5-羟色胺细胞进行了免疫组织化学定位和形态学观察.结果 表明:5-HTIR细胞在棕色田鼠胃肠道的各段均有分布,其中以十二指肠和直肠段分布密度最高,胃底、胃幽门部、空肠、回肠、盲肠段其次,胃贲门部、胃体、结肠段分布密度最低.5-羟色胺细胞位于胃腺上皮、肠粘膜上皮、肠腺上皮及固有膜,有圆形、椭圆形、梭形、楔形和不规则形,有的还具有胞突.对棕色田鼠胃肠道5-HTIR细胞的分布、形态与功能相适应的特点进行了讨论.  相似文献   

9.
扬子鳄胚胎背腺的发生及退化   总被引:1,自引:0,他引:1  
本文在14例扬子鳄Alligatorsinensis胚胎中观察了背腺的发生及退化过程。孵化第28天,背中线左右两侧第二行鳞片处的表皮内陷形成实心的背腺腺芽;第38天,背腺腺泡明显,腺上皮为复层上皮;从第46天开始,腺上皮出现明显的退化,大量增殖的腺管上皮细胞逐渐堵塞腺管及腺孔。扫描电镜观察表明,孵化第32—36天的胚胎背部第二行鳞的各列鳞片表面均有背腺腺孔,以后逐渐出现少数不规则的退化,孵化第58天以后,绝大多数背腺腺孔消失。对扬子鳄背腺的发生及退化现象作了讨论。  相似文献   

10.
香鱼消化道及肝脏的形态结构特征   总被引:2,自引:0,他引:2  
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。  相似文献   

11.
Information about the saccharides expressed in gastric mucosa is mostly limited to the glycan content of gastric mucins and there are only a few studies of the glycoprofiling of the constituent cells and their components. Knowledge of the glycan expression of normal gastric mucosa is necessary for the interpretation of the significance of changes of expression in disease. A lectin histochemical study of normal human gastric (body) mucosa was performed using 27 lectins chosen to probe for a wide range of oligosaccharide sequences within several categories of glycoprotein glycans. There were marked differences in staining reactions in the various microanatomical structures of the mucosa, particularly between pits and glands with the former more closely resembling the surface epithelium. A notable feature was the degree of difference in the staining between a substantial sub-population of cells within the neck region and the epithelium of both the pits and glands. These neck cells resembled the pit cells with some lectins, glandular cells with some others and neither with some other lectins. Overall, the differences between the pit, gland and neck epithelia were diverse and numerous, and could not be explained by altered activity of a small set of glycosyltransferases. Widespread alterations of glycans must have occurred (affecting terminal and internal parts of their structures) and the very different glycotypes of the pit, neck and gland epithelia are, therefore, suggestive of the existence of three cell lineages within normal gastric epithelium. Published in 2004. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

12.
This paper was inspired by the reported results of authors from Uppsala and Lund that gastric glands in rats rhythmically contract 3-7 cycles per minute and develop luminal pressures more than 10 mmHg. To ensure that pepsinogen is not retained in the acid-rich section of the gland, ejection fractions would need to be more than 50% of the gland volume. We have tried to calculate the ejection fraction of such contractions. Dimensions of human gastric glands were measured on the fresh frozen samples of macroscopically and histologically normal gastric mucosa. In total, 18 specimens (from nine persons) were measured under the microscope. The density of glands was 135 +/- 11 (mean +/- S.D.) glands per mm( 2) of gastric mucosa. A typical gastric gland is a tubular structure 1.2 +/- 0.22 mm long and 0.03-0.05 mm wide. We have used 1 mm for length and 0.03 mm for the gland diameter to calculate that each gland approximates a volume of 707 pl, suggesting that the total glandular volume for 15 million glands reaches 10.6 ml. Further calculations based on one to five contractions per minute on an average and on the total volume of gastric glands of 10 ml showed that only ejection fractions less than 10% deliver daily volumes less than 3 l. The presented model of the gastric gland activity is based on the idea that the low ejection fractions require a reduction of the glandular dead space. The reduced luminal pressure during the gland relaxation might cause backflux of hydrophobic viscoelastic mucus through the gland aperture. Repeated glandular contractions and relaxations would move the mucus all the way to the gland bottom, filling the gland cavity below the neck with an axial semisolid mucous cylinder. This filling would reduce the gland dead space. During contractions, the gland would eject mainly the peripheral, the more liquid part of its content. The decreasing luminal pressure in the relaxing gland would pull the outlet mucus inside, protecting gland apertures from the gastric juice.  相似文献   

13.
Lectin histochemistry of normal human gastric mucosa   总被引:2,自引:0,他引:2  
Information about the saccharides expressed in gastric mucosa is mostly limited to the glycan content of gastric mucins and there are only a few studies of the glycoprofiling of the constituent cells and their components. Knowledge of the glycan expression of normal gastric mucosa is necessary for the interpretation of the significance of changes of expression in disease. lectin histochemical study of normal human gastric (body) mucosa was performed using 27 lectins chosen to probe for a wide range of oligosaccharide sequences within several categories of glycoprotein glycans. here were marked differences in staining reactions in the various microanatomical structures of the mucosa, particularly between pits and glands with the former more closely resembling the surface epithelium. A notable feature was the degree of difference in the staining between a substantial sub-population of cells within the neck region and the epithelium of both the pits and glands. These neck cells resembled the pit cells with some lectins, glandular cells with some others and neither with some other lectins. Overall, the differences between the pit, gland and neck epithelia were diverse and numerous, and could not be explained by altered activity of a small set of glycosyltransferases. Widespread alterations of glycans must have occurred (affecting terminal and internal parts of their structures) and the very different glycotypes of the pit, neck and gland epithelia are, therefore, suggestive of the existence of three cell lineages within normal gastric epithelium.  相似文献   

14.
15.
Caecilians are exceptional among the vertebrates in that males retain the Mullerian duct as a functional glandular structure. The Mullerian gland on each side is formed from a large number of tubular glands connecting to a central duct, which either connects to the urogenital duct or opens directly into the cloaca. The Mullerian gland is believed to secrete a substance to be added to the sperm during ejaculation. Thus, the Mullerian gland could function as a male accessory reproductive gland. Recently, we described the male Mullerian gland of Uraeotyphlus narayani using light and transmission electron microscopy (TEM) and histochemistry. The present TEM study reports that the secretory cells of both the tubular and basal portions of the tubular glands of the male Mullerian gland of this caecilian produce secretion granules in the same manner as do other glandular epithelial cells. The secretion granules are released in the form of structured granules into the lumen of the tubular glands, and such granules are traceable to the lumen of the central duct of the Mullerian gland. This is comparable to the situation prevailing in the epididymal epithelium of several reptiles. In the secretory cells of the basal portion of the tubular glands, mitochondria are intimately associated with fabrication of the secretion granules. The structural and functional organization of the epithelium of the basal portion of the tubular glands is complicated by the presence of basal cells. This study suggests the origin of the basal cells from peritubular tissue leukocytes. The study also indicates a role for the basal cells in acquiring secretion granules from the neighboring secretory cells and processing them into lipofuscin material in the context of regression of the Mullerian gland during the period of reproductive quiescence. In these respects the basal cells match those in the epithelial lining of the epididymis of amniotes.  相似文献   

16.
目的观察扬子鳄中脑视叶一氧化氮合酶(nitric oxide synthase,NOS)和乙酰胆碱酯酶(acetylcholinesterase,AChE)阳性神经元的形态和分布,为扬子鳄脑的比较解剖学积累资料,为其机能研究提供形态学依据。方法采用还原型尼克酰胺腺嘌呤二核苷酸黄递酶(NADPH-d)法和亚铁氰化酮法观察扬子鳄中脑视叶NOS和AChE阳性神经元的分布和特征,并作统计学处理。结果扬子鳄中脑视叶有NOS和AChE阳性神经元分布,为大、中、小型细胞,以中、小型细胞为主,胞体呈椭圆形、三角形、圆形和梭形。结论扬子鳄中脑视叶有NOS和AChE阳性神经元分布。  相似文献   

17.
Duodenal samples were taken from similar locations in six cats, processed, stained, and examined via light microscope. There were no prominent circular folds (plicae circulares) or stratum compactum (lamina subglandularis). The 1072 microns x 201 microns villi were covered by 46 microns high columnar epitheliocytes proximally which decreased in height (41 microns) distally and displayed a 1.1-1.7 microns striated border. Globular leukocytes, mononuclear cells, and twenty-eight goblet cells (exocrinocytus calciformis) per villus were seen. The intestinal gland (crypt of Lieberkuhn) epithelium was 20 microns tall and had a less distinct striated border. The 515 microns simple straight tubular intestinal gland layer displayed distal branching. Many mitotic figures, 12 goblet cells per gland, and occasional columnar to triangular cells with red cytoplasmic granules were seen. The thickness of the lamina propria mucosa (glandular portion) decreased from proximal to distal (563-465 microns). The lamina muscularis mucosa had two layers and decreased in thickness distally (71-28 microns). The proximal muscularis mucosa was penetrated by the ducts of submucosal (Brunner's, duodenal) glands. The tela submucosa decreased in thickness distally (593-192 microns) and contained submucosal glands with 11.5-75 microns lumina for the first 1.5-2.5 cm. However, submucosal glands could be found to a distance of 8 cm. The glandular epithelium ranged from 7.5-22.5 microns in height. Only one type of secretory cell was observed, with both mucous and serous properties. The tunica muscularis ranged from 190-1425 microns (median thickness of 557 microns) and had two layers.  相似文献   

18.
The stomach of Oreochromis niloticus has three regions   总被引:6,自引:0,他引:6  
The stomach of Oreochromis niloticus was divided into three distinct regions: initial, middle and terminal, corresponding roughly to the cardiac, fundic, and pyloric portions of the mammalian stomach. Grossly, the organ showed initial and terminal portions, the former connected to the distal part of the oesophagus and the latter to the proximal portion of the intestine. There was also a middle region, forming a large blind diverticulum communicating with the first two at their point of junction. The initial or cardiac region was shorter than the middle region but longer than the terminal one, and had a smooth surface devoid of gastric pits. The epithelium in this region was simple columnar devoid of goblet cells, with glandular regions in the lamina propria. The mucosa of the middle or fundic region had gastric pits lined by columnar epithelium, and simple tubular glands filled most of the lamina propria. The terminal or pyloric part of the stomach was very short and its mucosa was slightly folded and devoid of both gastric pits and mucous glandular cells. The lining epithelium of this portion of the stomach was simple columnar and a few goblet cells were seen at its junction with the first part of the intestine. The tunica muscularis of the stomach contained skeletal muscle in the initial and terminal regions, usually intermingled with smooth muscle fibres. Skeletal muscle fibres were also observed in the first portion of the small intestine, near the junction with the stomach.  相似文献   

19.
扬子鳄(Alligator sinensis)的舌腺   总被引:3,自引:0,他引:3  
扬子鳄舌粘膜固有层内,除舌尖外可见到许多舌腺,特别是沿舌背中线两侧数量尤多,其形状和大小不一,有简单的单管腺,也有复杂的复管泡状腺,全舌约有舌腺100个。舌腺于胚鳄将破壳时发生。最早出现在距舌尖约三分之一处,随后,舌后和舌尖的稍后方相继出现舌腺,约一个月龄,幼鳄的舌腺仍在发育中。舌腺的发生由粘膜上皮内折、特化成腺泡和导管。扬子鳄舌腺除滑润食物外,还具排泄氯化钠的功能。  相似文献   

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