首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 624 毫秒
1.
应用透射电镜技术,对15只正常中华鳖小肠和大肠黏膜上皮细胞的超微结构进行了研究。结果表明,中华鳖小肠黏膜上皮为单层柱状上皮,以高柱状吸收细胞为主,具有发达的微绒毛、线粒体、粗面内质网和膜包小囊泡,其结构的发达程度已接近高等哺乳动物和鸟类。吸收细胞之间可见少量低电子密度的亮细胞,其种类需进一步确定。杯状细胞明显可见,胞质内含大量黏液性颗粒,细胞游离面形成明显的微绒毛。内分泌细胞很少。大肠黏膜上皮细胞排列松散,全部由上下粗细不均的柱状细胞组成。大肠上皮内未见专门的杯状细胞,但上皮细胞顶部胞质内含大量黏液颗粒,细胞器分布于黏液颗粒团之下的胞质中。细胞间隙宽大明显,有利于黏膜免疫细胞出入上皮。小肠和大肠均未见腺体分布。  相似文献   

2.
为阐明兔胎儿肺脏发育的组织形态学特征,采集4组兔胎儿(平均体长分别为1.9、2.75、4.7 cm和10.35 cm)肺脏,经制备石蜡切片,显微镜观察组织结构变化。结果显示,1.9 cm组,肺脏只见两条主支气管,由假复层柱状上皮组成;2.75 cm组,已形成支气管树,分支形成许多腺管状的细支气管结构,末端形成终蕾;在4.7 cm组,已形成终末细支气管,由单层立方上皮构成;10.35 cm组,已形成终囊(原始肺泡),囊壁较厚,只有少量终囊分化出肺泡Ⅰ型和Ⅱ型细胞,但也存在未形成终囊及终末细支气管的肺间质区域。这些结果表明,4组兔胎儿肺脏发育分别处于肺芽期、假腺期、小管期和终囊期。  相似文献   

3.
哺乳动物胎肺发育的形态学研究   总被引:3,自引:0,他引:3  
哺乳动物胎肺的发育可以分5个时期:胚胎期、假腺期、小管期、囊状期和肺泡期。人、绵羊和山羊胎儿至出生时肺的发育已基本完善,处于肺泡期;而兔、大鼠和小鼠的胎儿至出生时肺的发育尚处于囊状期。甩泡表面上皮细胞的分化和气血屏障的形成是肺发育的形态学标志。呼吸功能的建立,与Ⅱ型上皮细胞的分化密切相关。Ⅱ型细胞的分化标志有以下几点:①糖原的变化;②粗面内质网池扩张,并出现絮状物质;③多泡体出现及高尔基小泡增多;④胞质内微管出现;⑤腔面生成微绒毛;⑥致密小体内板层的出现等。  相似文献   

4.
用透射电镜技术对重口裂腹鱼消化道黏膜的超微结构进行了观察。结果显示:口咽腔和食道黏膜上皮均为复层上皮,上皮中存在大量粘液细胞,相邻细胞间通过发达的犬牙交错的桥粒紧密相连,表层和中间层细胞中有较多致密颗粒,表层细胞游离端表面有绒毛状突起。前肠吸收细胞微绒毛长而密,细胞质中线粒体、滑面内质网、粗面内质网、高尔基体发达。后肠吸收细胞微绒毛短而粗,终末网区中吞饮小泡较多。巨噬细胞中有多量溶酶体,其中见有凋亡细胞。2种形态的肥大细胞含大量分泌颗粒。肠黏膜上皮中存在少量凋亡细胞,其胞体、胞核和胞质均见有明显的形态学变化。  相似文献   

5.
为确定鸡轮状病毒感染的病理变化特点,对自然发病和人工发病轮状病毒感染鸡进行了病理学研究。结果表明,该病特征性的病理剖检变化为肠黏膜脱落出血,呈卡他性炎症表现。特征性组织学变化为小肠绒毛显著缩短,肠腺深度增加;除肠绒毛缩短外,肠上皮还变为扁平或立方形,并伴发坏死、脱落,黏膜充血、水肿与淋巴细胞浸润。电镜观察,肠黏膜上皮细胞的线粒体肿胀,嵴变粗,排列紊乱;粗面内质网及滑面内质网均扩张呈圆形,粗面内质网表面的核糖体部分脱落,胞浆内游离的核糖体减少。  相似文献   

6.
《中国兽医学报》2016,(5):814-818
为了揭示成年牦牛扁桃体组织结构和黏膜免疫相关细胞的分布规律,本研究采用组织化学法、图像分析法与透射电镜技术,对牦牛扁桃体的形态特征及免疫相关组织与细胞的分布特征进行了详细的研究。结果显示,牦牛共有6个扁桃体,其基本结构主要由上皮层和固有层构成。口咽部扁桃体上皮主要由复层扁平上皮细胞组成,上皮组织结构紧密;鼻咽部扁桃体上皮主要由假复层纤毛柱状上皮细胞组成,在柱状细胞之间分布有大量的杯状细胞;二者上皮层细胞组成差异较大,厚度及上皮内淋巴细胞的数量差异极显著(P0.01)。并且,两者上皮下肥大细胞与淋巴小结的数量也差异极显著(P0.01)。电镜下,腭扁桃体与咽鼓管扁桃体上皮细胞间有大量的连接复合体,且咽鼓管扁桃体上皮细胞游离面有大量排列整齐的微绒毛。肥大细胞的胞质内聚集有许多高电子密度的颗粒。浆细胞核的周围有丰富的粗面内质网和核糖体,胞质中有黏液颗粒。结果表明,牦牛扁桃体组织结构和其他家畜基本相似,但扁桃体分布位置有所不同,且牦牛扁桃体免疫相关组织与细胞分布较丰富,其中腭扁桃体隐窝中分布有较多的杯状细胞,显示牦牛扁桃体具有更发达的黏膜免疫活性。  相似文献   

7.
《养猪》2016,(5)
正气道可分为气管、支气管、细支气管和肺泡等不同区段,在不同区段里,其上皮细胞的类型和组成不尽相同,主要的气道上皮细胞包括基细胞、克拉拉细胞、纤毛柱状细胞、杯状细胞、肺泡Ⅰ型细胞和肺泡Ⅱ型细胞等。不同物种气道上皮细胞的类型和比例也不尽相同。基细胞和克拉拉细胞是比较重要的具有干细胞潜能的气道上皮细胞。基细胞体积较小,呈锥形或三棱形,核大,沿基膜排列,是一种低分化  相似文献   

8.
捻转血矛线虫中肠由单层上皮细胞所组成,未见明确的细胞界限,并向肠腔内伸出相互平行、排列整齐的微绒毛,长约6.5μm,微绒毛中心由纵贯微绒毛并相互平行的微丝构成;细胞核位于细胞中部,核膜清楚,体形大,形状不规则,有一较大的核仁,异染色质凝集成块状,电子致密度甚高。分散于核质中;上皮细胞中部细胞器丰富,有粗面内质网、线粒体、高尔基体及溶酶体;基部为胶原纤维样,并含有丰富的内质网。  相似文献   

9.
应用光镜和透射电镜技术,研究2月龄非洲雏鸵鸟甲状腺的显微和超微结构。结果表明,非洲雏鸵鸟甲状腺实质由甲状腺滤泡和滤泡旁细胞组成;甲状腺滤泡大小不一,直径20.0~280.0μm,平均69.9μm;滤泡主要由单层立方上皮细胞围成,上皮细胞高5.0~15.0μm,平均9.4μm。电镜下,滤泡上皮细胞分为A、B两型,A型细胞呈立方形或低柱状,胞核较大,常染色质丰富;胞质内RER、线粒体、高尔基复合体和溶酶体等细胞器丰富;B型细胞呈扁平或低立方形,胞核扁椭圆形,异染色质较多;胞质内各种细胞器不发达。滤泡旁细胞卵圆形或多边形,数量较少,胞体较大,位于滤泡间或滤泡上皮细胞之间;胞质内RER、线粒体、高尔基复合体和分泌颗粒较多。研究结果提示2月龄非洲雏鸵鸟的甲状腺功能比较活跃,能够合成、分泌较多的甲状腺激素和一定量的降钙素。  相似文献   

10.
用组织块培养法获得山羊乳腺细胞原代培养物。根据山羊乳腺成纤维细胞与上皮细胞对胰蛋白酶的敏感性不同将二者分离纯化,对细胞生长特性进行了光镜观察。结果如下:细胞可形成闭合型细胞群和开放型细胞群。乳腺上皮细胞与成纤维细胞混生时,细胞之间形成许多腔状结构。纯化的乳腺上皮细胞通过单细胞悬浮后传代,部分细胞形成岛屿状聚集,部分细胞以贴壁的自由单个细胞散在形式存在。上皮细胞增殖可形成圆顶型结构,呈乳头状,称之为乳球体;可产生乳腺上皮细胞并分泌乳汁。山羊乳腺上皮细胞含不同的细胞类型.大多数上皮细胞呈短梭形或多角形。细胞之间紧密相靠。互相衔接。连接成片,呈蜂窝状;细胞核呈圆形或椭圆形.核仁2~4枚;部分细胞呈圆饼状,体积较大;出现部分长形细胞;接触抑制的上皮细胞形态不均一。纯化的山羊乳腺上皮细胞传代至第15代时其生长仍正常,经透射电镜观察发现细胞表面微绒毛极为发达,细胞质中线粒体和粗面内质网丰富,细胞质内有大量脂滴及小泡,表明第15代山羊乳腺上皮细胞增殖活力旺盛。染色体数目分析表明.该细胞系稳定,在离体培养条件下细胞不发生转化。山羊乳腺上皮细胞系的细胞染色体数目为60.染色体组型为2n=60。  相似文献   

11.
As there is no statistical evidence that saddle fit influences the load exerted on a horse's back, this study was performed to assess the hypothesis that the width of the tree significantly alters the pressure distribution on the back beneath the saddle. Nineteen sound horses were ridden at walk and trot on a treadmill with three saddles differing only in tree width. Kinetic data were recorded by a sensor mat. A minimum of 14 motion cycles were used in each trial. The saddles were classified into four groups depending on fit. For each horse, the saddle with the lowest overall force (LOF) was determined. Saddles were classified as "too-narrow" if they were one size (2 cm) narrower than the LOF saddle, and "too-wide" if they were one size (2 cm) wider than the LOF saddle. Saddles two sizes wider than LOF saddles were classified as "very-wide". In the group of narrow saddles, the pressure in the caudal third (walk 0.63 N/cm(2)+/-0.10; trot 1.08 N/cm(2)+/-0.26) was significantly higher compared to the LOF saddles (walk 0.50 N/cm(2)+/-0.09; trot 0.86 N/cm(2)+/-0.28). In the middle transversal third, the pressure of the wide saddles (walk 0.73 N/cm(2)+/-0.06; trot 1.52 N/cm(2)+/-0.19) and very-wide saddles (walk 0.77 N/cm(2)+/-0.06; trot 1.57 N/cm(2)+/-0.19) was significantly higher compared to LOF saddles (walk 0.65 N/cm(2)+/-0.10/ 0.63 N/cm(2)+/-0.11; trot 1.33 N/cm(2)+/-0.22/1.27 N/cm(2)+/-0.20). This study demonstrates that the load under poorly fitting saddles is distributed over a smaller area than under properly fitting saddles, leading to potentially harmful pressures peaks.  相似文献   

12.
Complications in late gestation are challenging problems for the equine clinician and are causes of considerable distress to owners. Health problems in a pregnant mare in each stage of gestation can adversely affect the pregnancy. It is important to obtain a thorough history and perform a detailed and systematic examination of the pregnant mare so that the mare may be classified as normal or high-risk. However, even after a thorough examination, practitioners may face problems with the interpretation and assessment of risk. Normal mares should foal in the stable or pasture. Mares classified as having a high-risk pregnancy need to be monitored precisely for signs of oncoming foaling with attendance of trained personnel when labour begins. A valuable method for monitoring of the high-risk mare is assessing fetoplacental well-being. Fetoplacental well-being is most accurately assessed with ultrasonography as well as several available hormone profiles. We are proposing our scoring system of the mare's health, which may be useful in the assessment of risk during pregnancy and help clinicians to decide whether sending the mare to the clinic is reasonable or unnecessary.  相似文献   

13.
顾问刘中一张德邻宋瑞祥聂振邦张子仪戎易王维四会长白美清国务院原副秘书长、第四届理事会会长常务副会长(8人,以姓氏笔划为序)刘永好新希望集团董事长、第四届理事会副会长刘汉元通威股份有限公司董事长、第四届理事会副会长陈丹广东恒兴集团股份有限公司董事长、第四届理事会副会长张延喜农业部原副部长、第四届理事会副会长吴明夏湖南正虹科技发展股份有限公司董事长、第四届理事会副会长陶一山唐人神集团股份有限公司董事长、第四届理事会副会长温鹏程广东温氏食品集团有限公司董事长、第四届理事会副会长谭竹洲原化学工业部副部长、第…  相似文献   

14.
为了找出支配鸡胆囊交感节后神经元的分布规律,选用体重1.5 kg~2.5 kg的成年母鸡6只,将CT-HRP溶液注入胆囊壁,动物存活3 d~4 d后,经左心室灌流固定,取内脏神经节、肾上腺神经节以及双侧胸、腰和荐段交感干神经节,制成50 μm的连续冰冻切片,TMB法呈色反应,置明视野显微镜下观片统计.结果发现,支配鸡胆囊的交感传出神经元胞体位于内脏神经节(占41.1%)、肾上腺神经节(占40.5%)和T2~T7交感干神经节(占18.4%),在交感干神经节中标记细胞的峰值位于T5、T6交感干神经节.所有的标记细胞以位于右侧的占优势.  相似文献   

15.
The understanding and application of genetics have grown extremely quickly since it has become possible to sequence the whole genome of an organism. The human genome sequence was completed in 2001 and that of the horse in 2007. The significance of this is that it makes it more feasible to explain how both genetically simple and complex traits are transmitted from one generation to the next and, therefore, to make informed breeding decisions, modify how horses are managed and trained to minimise the risk of disease and injury, and improve methods of prevention, diagnosis and treatment of many conditions. The science of genetics/genomics will continue to grow internationally, limited only by the funds available. The application of the science to man, horses and other species raises very complex moral and commercial issues. Thoroughbred breeders are perceived by some as resistant to change, but their apparent intransigence is often based on a genuine concern for the integrity of the breed. By taking control of the application of the advances in genetics, the Thoroughbred industry potentially has the opportunity to improve both the health and performance of Thoroughbreds. If, however, the science is applied in an uncoordinated manner, driven by commercial interests with no underlying concern for the horses themselves, there is a very real risk that breeders, the Thoroughbred breed and individual horses will all suffer as a consequence.  相似文献   

16.
犊牛腹泻与肠道菌群的变化   总被引:1,自引:0,他引:1  
本文检测腹泻犊牛的直肠内8种主要正常菌群的变化,并与健康犊牛进行对比。结果发现,犊牛腹泻时,大肠杆菌、双岐杆菌和乳杆菌变化较大,而其它菌群变化较小。腹泻或将腹泻时,大肠杆菌数增加,双岐杆菌和乳杆菌数下降。腹泻康复或即将康复时,大肠杆菌减少,双岐杆菌、乳杆菌数增加。  相似文献   

17.
赵云翔  赵蕊  张恒  郭金彪 《养猪》2022,(1):52-55
试验以深圳某集团销售外三元商品猪为研究对象,分析了商品猪不同胴体性能对分割销售效益的影响.结果表明,销售完成率与胴体背膘厚呈正相关,不同背膘厚的销售完成率差异极显著(P<0.01);销售完成率与胴体重呈正相关,不同胴体重的销售完成率差异显著(P<0.05);销售毛利率与胴体背膘厚呈正相关,不同背膘厚的销售毛利率差异极显...  相似文献   

18.
试验选择陕北白绒山羊繁育中心羊场的成年健康母羊(怀孕前期)16只,育成母羊13只,育成公羊13只,空腹称重。测定每只羊1d的采食量,计算其摄入的营养成分含量,并与原苏联绒用山羊饲养标准比较,进行饲养水平评价。结果显示,与饲养标准比较,陕北白绒山羊繁育中心羊场的育成母羊代谢能高2.68MJ,粗蛋白低59.29g,钙低3.00g,磷低1.52g;育成公羊代谢能高3.47MJ,粗蛋白低81.92g,钙低4.42g,磷低2.62g;成年母羊代谢能高2.51MJ,粗蛋白低91.33g,钙低3.09g,磷低1.93g。结合羊的体况综合评价饲养水平基本合理,但尚需要按饲养标准增加粗蛋白、钙、磷等营养物质的供给量。  相似文献   

19.
20.
Progesterone levels in peripheral blood of dogs were analysed during the cycle in which hysterectomy (n = 5) or sham surgery (n = 3) was performed as well as during the cycle of dogs (n = 5) hysterectomized at least one year prior to this study; the data were compared with the findings in control dogs (n = 3). The averages of the duration of the luteal period observed in the three experimental groups were not significantly different from those of control dogs. Immediately after surgery, the progesterone level decreased from 25 to 50% of the presurgical level, but returned to presurgical level in about four days. Prolactin levels were elevated for about 30 h after surgery. Nevertheless, the averages of the mean prolactin levels for each animal during the luteal period of the experimental groups were not significantly different from those of control dogs. It is concluded that in the dog, the uterus is not involved in the lifespan of the cyclic corpus luteum.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号