胚胎学总论试题.pdf

82 第20章 胚胎学总论和畸形学概论 GENERAL EMBRYOLOGY AND TERATOLOGY 第20章 胚胎学总论和畸形学概论 GENERAL EMBRYOLOGY AND TERATOLOGY 目的与要求目的与要求 掌握受精的概念 过程 部位和意义 掌握卵裂 桑椹胚及胚泡的概念 掌握植入的概念 过程 部位及异常植入 掌握二胚层及其相关结构的形成 掌握三胚层及其相关结构的形成 掌握三胚层分化 熟悉胎膜的组成及其作用 胎盘的一般结构和功能以及胎盘屏障的结构和功能 了解双胎和联体的成因 熟悉先天性畸形的发生原因 掌握致畸敏感期 OUTLINEOUTLINE Primordial germ cells appear in the wall of the yolk sac in the fourth week and migrate to the in different gonad where they arrive at the end of the fifth week In preparation for fertilization both male and female germ cells undergo gametogenesis which includes meiosis and cytodifferentiation Mature male and female gametes have respectively 22 plus X or 22 plus Y chromosomes Before spermatozoa can fertilize the oocyte they must undergo a capactation during which time a glycoprotein coat and seminal plasma protein are removed from the spermatozoon head and b the acrosome reaction during which acrosin and trypsin like substances are released to penetrate the zona pellucida During fertilization the spermatozoon must penetrate a the corona radiata b the zonapellucida and c the oocyte cell membrane As soon as the spermatocyte has entered the oocyte a the oocyte finishes its second meiotic division and forms the female pronucleus b the zona pellucida becomes impenetrable to others permatozoa and c the head of the sperm separates from the tail swells and forms the male pronucleus The results of fertilization are a restoration of the diploid number of chromosomes b determination of chromosomal sex and c initiation of cleavage Cleavage is a series of mitotic divisions that results in an increase in cells blastomeres After three divisions blastomeres undergo compaction to become a tightly grouped ball of cells with inner and outer layers Compacted blastomeres divide to form a 16 cell morula As the morula enters the uterus on the third or fourth day after fertilization a cavity begins to appear and the blastocyst forms The inner cell mass which is formed at the time of compaction and will develop into the embryo proper is at one pole of the blastocyst The outer cell mass which surrounds the inner cells and the blastocyst cavity will form the trophoblast The uterus at the time of implantation is in the secretory phase and the blastocyst implants in the endometrium along the anterior or posterior wall If fertilization does not occur then the menstrual phase begins and the spongy and compact endometrial layers are shed The basal layer remains to regenerate the other layers during the next cycle At the beginning of the second week the blastocyst is partially embedded in the endometrial stroma The trophoblast differentiates into a an inner actively 83 proliferating layer the cytotrophoblast and b an outer layer the syncytiotrophoblast which erodes maternal tissues The inner cell mass meanwhile differentiates into a the epiblast and b the hypoblast together forming a bilaminar disc Epiblast cells give rise to amnioblasts that line the amniotic cavity superior to the epiblast layer Endoderm cells are continuous with the exocoelomic membrane and together they surround the primitive yolk sac By the end of the second week extraembryonic mesoderm fills the space between the trophoblast and the amnion and exocoelomic membrane internally The most characteristic event occurring during the third week is gastrulation which begins with the appearance of the primitive streak which has at its cephalic end the primitive node In the region of the node and streak epiblast cells move inward invaginate to form new cell layers endoderm and mesoderm Hence epiblast gives rise to all three germ layers in the embryo The embryonic period which extends from the third to the eighth weeks of development is the period during which each of the three germ layers ectoderm mesoderm and endoderm gives rise to its own tissues and organ systems As a result of organ formation major features of body form are established The ectodermal germ layer gives rise to the organs and structures that maintain contact with the outside world a central nervous system b peripheral nervous system c sensory epithelium of ear nose and eye d skin including hair and nails and e pituitary mammary and sweat glands and enamel of the teeth Important components of the mesoderm are paraxial intermediate and lateral plate mesoderm Paraxial mesoderm forms somitomeres which give rise to mesenchyme of the head and organize into somites in occipital and caudal segments Somites give rise to the myotome muscle tissue sclerotome cartilage and bone and dermatome subcutaneous tissue of the skin which are all supporting tissues of the body The endoderm provides the epithelial lining of the gastrointestinal tract respiratory tract and urinary bladder It also forms the parenchyma of the thyroid parathyroids liver and pancreas Finally the epithelia lining of the tympanic cavity and auditory tube originate in the endoderm Fetal membrane chiefly includes chorion yolk sac amnion allantois and umbilical cord All of them originate from blastocyst having the same origin with embryo But they don t participate in the formation of embryo as the fetus is delivered they will be separated from fetus The placenta consists of two components a a fetal portion derived from the chorion frondosum and b a maternal portion derived from the deciduas basalis The space between the chorionic and decidual plates is filled with intervillous lakes of maternal blood The main function of the placenta is exchange of metabolic and gaseous product between maternal and fetal blood streams and production of hormones 练习题练习题 一 选择题 一 单项选择题 1 受精的部位一般在 一 选择题 一 单项选择题 1 受精的部位一般在 A 子宫体部或底部 B 输卵管峡部 C 输卵管壶腹部 D 输卵管漏斗部 2 透明带溶解消失发生在 2 透明带溶解消失发生在 A 受精时 B 卵裂时 C 胚泡期 D 桑椹胚期 3 受精卵的细胞分裂称 3 受精卵的细胞分裂称 A 卵裂 B 第一次成熟分裂 C 无丝卵裂 D 第二次成熟分裂 4 宫外孕多发生在 4 宫外孕多发生在 A 子宫阔韧带 B 输卵管 C 卵巢表面 D 膀胱壁 5 胚盘的原条出现在什么部位5 胚盘的原条出现在什么部位 A 中胚层尾端正中线 84 B 内胚层尾端正中线 C 外胚层尾端正中线 D 内胚层头端正中线 6 关于合体滋养层的描述错误的是 6 关于合体滋养层的描述错误的是 A 由胚泡的滋养层发育而成 B 细胞界限不清楚 C 能分化成胚外中胚层 D 合体滋养层的内侧有细胞滋养层 7 形成脊索的结构是 7 形成脊索的结构是 A 原条 B 原结 C 中胚层 D 内胚层 8 人胚初具人形的时间是 8 人胚初具人形的时间是 A 第 4 周末 B 第 6 周末 C 第 8 周末 D 第 10 周末 9 诱导神经管形成的结构是 9 诱导神经管形成的结构是 A 原条 B 原结 C 原凹 D 脊索 10 后神经孔未闭合可形成 10 后神经孔未闭合可形成 A 无脑儿 B 独眼畸形 C 无耳 D 脊髓裂 脊柱裂 11 胚内中胚层形成后 在脊索左右两侧 由内 向外依次分化为 11 胚内中胚层形成后 在脊索左右两侧 由内 向外依次分化为 A 间介中胚层 轴旁中胚层 侧中胚层 B 轴旁中胚层 间介中胚层 侧中胚层 C 轴旁中胚层 侧中胚层 间介中胚层 D 间介中胚层 侧中胚层 轴旁中胚层 12 可分化为肾上腺实质的胚层 12 可分化为肾上腺实质的胚层 A 内胚层和外胚层 B 内胚层和中胚层 C 中胚层和外胚层 D 中胚层 13 胎膜是指 13 胎膜是指 A 绒毛膜 羊膜 卵黄囊 尿囊 脐带 B 绒毛膜 羊膜 卵黄囊 尿囊 基蜕膜 C 绒毛膜 羊膜 卵黄囊 体蒂 脐带 D 绒毛膜 羊膜 包蜕膜 尿囊 脐带 14 原始生殖细胞来源于 14 原始生殖细胞来源于 A 卵黄囊壁的胚外中胚层 B 胚盘中胚层 C 卵黄囊壁的内胚层 D 间介中胚层 15 不参与脐带形成的结构是 15 不参与脐带形成的结构是 A 脐血管 B 卵黄囊 C 绒毛干 D 体蒂 16 不是由受精卵发育而来的结构有 16 不是由受精卵发育而来的结构有 A 胚盘 B 脐带 C 羊膜 D 蜕膜 17 胎儿诞生时 剪断脐带后从切口流出来的血 液应该是 17 胎儿诞生时 剪断脐带后从切口流出来的血 液应该是 A 胎儿的动脉血 B 母体的动脉血和胎儿的静脉血 C 胎儿的动脉血和母体的静脉血 D 胎儿和母体的动 静脉血 18 胎盘的结构有哪两部分组成 18 胎盘的结构有哪两部分组成 A 胎儿平滑绒毛膜与母体包蜕膜 B 胎儿平滑绒毛膜与母体基蜕膜 C 胎儿丛密绒毛膜与母体基蜕膜 D 胎儿丛密绒毛膜与母体包蜕膜 19 绒毛通过什么结构固定在子宫基蜕膜上 19 绒毛通过什么结构固定在子宫基蜕膜上 A 细胞滋养层壳 B 胚外中胚层 C 基膜 D 合体滋养层 20 作早期妊娠诊断时 通常是测孕妇尿中的 20 作早期妊娠诊断时 通常是测孕妇尿中的 A 雌激素 B 人绒毛膜促性腺激素 C 孕激素 D 促乳腺生长素 二 多项选择题 1 受精卵的染色体组型是 二 多项选择题 1 受精卵的染色体组型是 A 44 XY B 22 XY C 44 XX D 22 XX 2 胚泡的正常植入部位一般是在 2 胚泡的正常植入部位一般是在 A 子宫底 B 子宫体 C 子宫颈 D 输卵管 3 胚泡植入时 3 胚泡植入时 A 滋养层细胞分泌蛋白酶分解子宫内膜 B 胚泡埋入子宫内膜基底层内 C 内细胞群一侧的滋养层先接触子宫内膜 D 桑椹胚逐渐埋入子宫内膜功能层内 4 外胚层分化为 4 外胚层分化为 A 表皮 B 汗腺 C 肾上腺髓质 D 神经系统 5 在胚盘变成圆柱形胚体的过程中 5 在胚盘变成圆柱形胚体的过程中 A 胚盘中部生长速度快于边缘部 B 内胚层被卷折到胚体内 形成原始消化管 C 胚体向羊膜腔内凸入 D 外胚层生长速度快于内胚层 6 关于子宫蜕膜的描述正确的有 6 关于子宫蜕膜的描述正确的有 A 子宫腺发达 分泌旺盛 B 基蜕膜是胚胎植入处的深部的蜕膜 C 血管生长 血供丰富 D 包蜕膜最发达 7 在三胚层胚盘时期没有中胚层的部位有 7 在三胚层胚盘时期没有中胚层的部位有 A 羊膜 B 口咽膜 C 泄殖腔膜 D 合体滋养层 8 胚内体腔将形成 8 胚内体腔将形成 A 心包腔 B 腹膜腔 C 羊膜腔 D 胸膜腔 9 中胚层分化形成的器官有 9 中胚层分化形成的器官有 A 肾 B 睾丸 C 子宫 D 垂体 10 关于原结和原条的描述正确的有 10 关于原结和原条的描述正确的有 A 原条尾端膨大形成原结 B 原结和原条分化形成中轴骨骼 C 原条是胚盘外胚层尾侧中线处的一条增厚区 D 原条的细胞在内 外胚层之间增殖扩展成中 胚层 11 关于羊水的描述正确的有 11 关于羊水的描述正确的有 A 羊膜不断吸收 分泌羊水 B 胎儿可吞饮少量羊水 C 胎盘血液内的部分物质渗入羊水内 85 D 胎儿体内少量代谢废物排入羊水中 二 填空题 二 填空题 1 胚胎发育从受精卵形成到胎儿娩出约 周 分 和 两个阶段 2 Fertilization the process by which male and female gametes fuse occurs in the 3 Once the zygote has reached the two cell stage it undergoes a series of mitotic divisions increasing the numbers of cells These cells which become smaller with each cleavage division are known as Approximately 3 days after fertilization cells of the compacted embryo divide again to form a 16 cell About the time they enters the 4 As the morula enters the uterus on the third or fourth day after fertilization a cavity begins to appear and the blastocyst forms It consists of and 5 常见的植入部位是 和 6 The inner cell mass or embryoblast meanwhile differentiates into a the and b the together forming a 7 根据蜕膜与胚泡的位置关系 通常将蜕膜分为三个部分 位居胚泡深面的部分称 覆盖在胚泡浅层的部分称 其余部位的蜕膜称 8 By the end of the third week trilaminar germ disc consists of and 9 Important components of the mesoderm are and 10 The fetal membrane consists of and 11 The placenta has two components a a fetal portion formed by the and b a maternal portion formed by the 12 第 3 周初 形成即决定了胚胎中轴 并可判断胚体的头尾 13 脊索的头侧有一圆形区无中胚层 称为 原条的尾侧有一圆形区无中胚层 称为 14 Appearance of the notochord induces the ectoderm to thicken and form the As a result the is formed 15 第 3 周末 轴旁中胚层形成成对的 16 胚胎最早形成的血管和血细胞的部位是在 由 细胞分化而来 17 第 2 周羊膜腔形成 它位于 与 之间 18 胎盘屏障由 和 构成 19 从卵黄囊顶部尾侧的内胚层伸向 的盲管 称为 20 Twins which develop from a single fertilized ovum is which develop from two fertilized ovum is 21 导致人类先天性畸形的原因包括 和 三 名词解释 三 名词解释 1 Capacitation 2 Fertilization 3 Acrosome reaction 4 Zona reation 5 Blastcyst 6 Implantation 7 Primitive streak 8 Placenta 9 Placental barrier 10 Congenital malformation 11 Susceptible period 86 四 问答题 四 问答题 1 叙述受精的部位 过程 条件和意义 2 叙述胚泡植入的时间 部位 过程及胚泡的变化 3 简述二胚层胚盘及相关结构的发生 4 叙述三胚层形成和分化 5 试述胎盘结构和功能 五 讨论与趣味思考题 五 讨论与趣味思考题 1 During implantation the trophoblast is invading maternal tissues and because it contains approximately 50 paternal genes it is a foreign body Why is the conceptus not rejected by an immunologic response from the mothers system 2 Why are the third to eighth weeks of embryogenes so important for normal development and the most sensitive for induction of structural defects 3 An ultrasound scan detects a large mass near the sacrum of a 28 week female fetus What might the origin of such a mass be and what type of tissue might it contain 参考答案 参考答案 一 选择题 一 单项选择题 一 选择题 一 单项选择题 1 C 2 C 3 A 4 B 5 C 6 C 7 B 8 C 9 D 10 D 11 B 12 C 13 A 14 C 15 C 16 D 17 A 18 C 19 A 20 B 二 多项选择题 二 多项选择题 1 AC 2 AB 3 AC 4 ABCD 5 ABCD 6 AC 7 BC 8 ABD 9 ABC 10 CD 11 ABD 二 填空题 二 填空题 1 胚期 胎期 2 输卵管的壶腹部 ampullary region of the uterine tube 3 卵裂球 blastomere 桑椹胚 morula 子宫腔 cavity of uterus 4 滋养层 trophoblast 内细胞群 inner cell mass 胚泡腔 blastocoele 5 子宫体部 子宫底部 6 上胚层 epiblast 下胚层 hypoblast 二胚层胚盘 bilaminar germ disc 7 底蜕膜 包蜕膜 壁蜕膜 8 内胚层 endoderm 中胚层 mesoderm 外胚层 ectoderm 9 轴旁中胚层 paraxial mesoderm 侧中胚层 lateralplate mesoderm 间介中胚层 intermediate mesoderm 10 绒毛膜 羊膜 卵黄囊 尿囊 脐带 11 丛密绒毛膜 chorion frondosum 底蜕膜 deciduas basalis 12 原条 13 口咽膜 泄殖腔膜 14 神经板 neural plate 神经管 neural tube 15 体节 16 卵黄囊壁 胚外中胚层 17 上胚层 细胞滋养层 18 合体滋养层 细胞滋养层和基膜 薄层绒毛结缔组织 毛细血管内皮和基膜 19 体蒂 尿囊 20 单卵双胎 monozygotic twins 双卵双胎 dizygotic twins 21 遗传因素 环境因素 环境与基因相互作用或原因不明 三 名词解释 三 名词解释 87 1 精子在女性生殖管道中运行过程中 包裹在精子头部的糖蛋白被女性生殖管道中的酶类降解 获得受精能力 此过程称获能 2 发育正常的精子与卵子结合成为受精卵的过程称受精 3 当精子接触到卵母细胞周围的放射冠和透明带时 其顶体释放顶体酶 溶蚀放射冠和透明带 此过程称顶体反应 4 精子核及胞质进入卵细胞的胞质时 皮质颗粒释放其内容物进入卵周隙 引起透明带中 ZP3 糖 蛋白分子的变化 使透明带失去了接受精子穿越的能力 这一过程称透明带反应 5 桑椹胚的细胞继续分裂增殖 当卵裂球的数目增至 100 个左右时 细胞间出现若干小的间隙 小间隙逐渐融合成一个大腔 腔内充满液体 整个胚形似囊泡 故称胚泡 6 胚泡逐渐埋入子宫内膜功能层的过程称植入 7 第 3 周初 上胚层细胞增生 在胚盘尾端形成一条纵行的细胞索 称原条 最终原条退化消失 8 胎盘为胎儿的丛密绒毛膜与母体的基蜕膜共同构成的圆盘状结构 是进行物质交换 分泌激素 和屏障外来微生物或毒素侵入 保证胎儿正常发育的重要器官 9 将母体血和胎儿血隔开 又能进行选择性物质交换所通过的结构 称胎盘屏障 胎盘屏障由绒 毛毛细血管内皮及其基膜 结缔组织 细胞滋养层及其基膜和合体滋养层构成 妊娠后期 只 由合体滋养层 毛细血管内皮和两者之间的基膜构成 10 先天性畸形是由于胚胎发育紊乱所致的形态结构的异常 出生即已存在 属于出生缺陷的一种 11 致畸敏感期指的是胚胎受到致畸因子作用最易发生畸形的发育阶段 称为致畸敏感期 四 问答题 四 问答题 1 1 受精部位 常见于输卵管的壶腹部 2 受精过程 分为三期 大量获能精子发生顶体反应 解离放射冠 精子与 ZP3 精子 受体 结合 融蚀透明带进入卵周隙 精子与卵子细胞膜融合 发生透明带反应 两性原核染色 体混合 形成受精卵 3 受精条件 发育正常的并且获能的精子与发育正常的卵子在限定的时间内相遇 4 受精的意义 是新生命的开端 恢复