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关键词： intestinal damage   hypoxia   hyperoxia   oxidative stress  

摘要： Background: Episodes of hypoxia and reperfusion play an important role in the development of intestinal damage during perinatal development. The aim of this study was to investigate the histopathology of the intestine in the developing chick embryo after exposure to repetitive hypoxia and recovery under two different conditions: normoxic and hyperoxic (60% O-2). Methods: Chick embryos were exposed to 5 minutes of hypoxia. This was repeated six times with a recovery period of 15 minutes under normoxic conditions (21% O-2) for chick embryos in test group 1 (TG1) and under hyperoxic conditions (100% O-2) for chick embryos in test group 2 (TG2). from day 11 until day 20. Chick embryos that recovered under hyperoxic conditions (100%,) were previously incubated under hyper oxic conditions (60%, for 24 hours). Histologic evaluation of the ileum was performed at different times after the interventions (2, 4, 8, 16, and 24 hours). Results: In both test groups. only chick embryos older than 19 days showed intestinal damage. Intestinal histology on day 19 showed vasodilation of villus capillaries (10% in TG1 and 15% in TG2), necrosis in the top of the villi (29% in TG1 and 30% in TG2), and necrosis with preservation of base of the crypts (2% in TG1) and transmucosal necrosis (2% in TG2). Conclusions: Significant histologic changes, compared with the control group, were only found in chick embryos that were studied 2 hours after the interventions. Furthermore, recovery under hyperoxic conditions did not cause more intestinal damage compared with recovery under normoxic conditions.

关键词： 电子化教学   CAI   组胚学   教案制作   电子教案  

摘要： CAI引入组胚学教学中在传递信息、尤其是图像信息方面显示出传统教学手段所无法比拟的优越性,对提高教学质量有很大帮助.本文介绍一种制作简单、实用方便的电子教案,用于教师备课,理论和实习课上可作为课件使用,还可记录最新进展和教学反馈.

关键词： 课堂提问   组织胚胎学   解剖学   小肠壁  

摘要： 在多年的教学实践过程中,我发现,课堂提问可激起学生对旧知识的回忆,激发学生对新知识的追求;可以优化课堂教学过程,使师生处于和谐的信息交流状态;使课堂处于紧张、活泼、有趣的气氛中;可以很好地开发学生的思维能力,检查教学效果,提高教学质量.但是课堂提问并不是问得越多越好,而在于'精问'、'巧问'、'善问'.可见,课堂提问既具有科学性,也具有艺术性.因此,我们在进行组织教学,设计课堂提问时,必须注意以下几方面:

关键词： 组织胚胎学   生物学   显微镜操作   本科生   改革   医学院  

摘要： 为了解普通医学院校本科生拥有组胚学所需的生物学知识与技能状况及影响因素和对组胚学教学的满意程度，对新乡医学院97级本科生进行了问卷调查并对结果进行了统计分析，结果显示普通医学院校本科生拥有组胚学所需的生物学知识状态偏差的占多数，95.26％的学生不合格，这种状态是由中学教学、学生入学状况及大学前期教学多方面造成的；大部分学生的显微镜操作与使用技能较弱，17.74％学生的显微镜操作与使用技能则弱至近乎无的状态。本研究提示普通医学院校本科生的生物学知识与技能状态较差、难以满足组胚教学的需要，必须采取得力措施以确保教学质量。

关键词： 组织胚胎学   教学   素质  

摘要： 强调组织胚胎学教师在教学过程中不仅要向学生传播知识，还应重视对学生学风、能力、哲学现、思想道德诸多方面的培养，把学生培养成专业基础知识扎实、善于观察、思维敏锐、修养良好的合格医学人材。

关键词： 组织胚胎学   教学   多媒体  

摘要： 组织胚胎学内容多,抽象复杂,传统教学手段单一,学生难以理解和记忆.引入多媒体技术可使授课生动、形象、逼真、直观,提高教学质量及效果,减轻教师负担,提高教师和学生综合素质.

关键词： 组织胚胎学   医学教育   绘图  

摘要： 作为一门重要的形态学课程，组织胚胎学所学习的对象更细微，结构之间的区别更小，名词繁多，内容抽象枯燥，对于刚入中专卫校的学生来说，学习上的难度是显而易见的。如何在课堂中调动学生学习的积极性、主动性，如何较好的运用“活”的教育方法去阐明“死”的组织学知识，让学生活学、活用、活记，下面谈谈我在教学中的一点体会：

关键词： 组织胚胎学   实验课   素质教育   教育改革   医学院校  

摘要： <中共中央国务院关于深化教育改革全面推进素质教育的决定>中指出:实施素质教育,就是全面贯彻党的教育方针,以提高国民素质为根本宗旨,以培养学生创新精神和实践能力为重点,造就'有理想、有道德、有文化、有纪律'的德、智、体、美等全面发展的社会主义事业建设者和接班人.

关键词： 组织胚胎学教学   形态学科   基础医学   医学科研   人体组织   临床诊断   医学生   教学过程   形象思维   培养  

摘要： 现代高校的教学过程应贯穿对学生基本素质的培养 ,基础医学中的形态学科如组织胚胎学的教学应侧重于培养学生的形象思维 ,为培养其想象能力发挥作用。在教学过程中通过对人体组织结构及其发育过程进行一系列的联想和想象 ,使学生逐步建立起医学形象思维 ,这对医学生将来的临床诊断和医学科研创新具有重要的意义。

关键词： chick embryo   development   spinal reflex pathway   synaptic function   voltage-sensitive dye  

摘要： We examined embryonic expression of postsynaptic potentials in stages 26-31 (E5 to E7) chick spinal cord slices. Slow optical signals related to the postsynaptic potentials which were evoked by electrical stimulation of afferent fibers were identified in the dorsal grey matter and the ventral motoneuronal area. In cervical spinal cord (C13) preparations, the dorsal slow signal appeared from stage 28 (E6), whilst the ventral slow signal was recognized from stage 29. At stages 26 and 27 (E5), no slow signal was observed in either the dorsal or ventral regions. On the other hand, in lumbosacral spinal cord (LS5) preparations, the dorsal, as well as ventral, slow signals appeared from stage 29;at stage 28 no slow signal was detected in the dorsal or ventral regions. These results suggest that there are differences in the ontogenetic expression of synaptic functions between the dorsal and ventral regions, and between the cervical and lumbosacral spinal cords. In embryos older than stage 29, removal of Mg2+ from the bathing solution markedly enhanced the amplitude and incidence of the ventral slow signal. In addition, in C13 preparations at stage 28, removal of Mg2+ elicited small slow signals in the ventral region in which no synaptic response was evoked in normal Ringer's solution. The slow signals induced in the Mg2+-free solution were blocked by 2-amino-5-phosphonovaleric acid (APV), showing that they are attributable to N-methyl- d-aspartate (NMDA) receptors. These results suggest that functional synaptic connections via polysynaptic pathways are already generated on motoneurons, but are suppressed by a Mg2+ block on the NMDA receptors at developmental stages when synaptic transmission from the primary afferents to the dorsal interneurons is initially expressed in the dorsal region.