notochord

简明释义

英[ˈnəʊtəˌkɔːd]美[ˈnotəˌkɔrd]

n. [胚] 脊索

英英释义

单词用法

同义词

反义词

例句

1.A segmental mass of mesoderm in the vertebrate embryo, occurring in pairs along the notochord and developing into muscles and vertebrae.

脊椎动物胚胎中胚层中的体节物质，沿脊索成对出现，后生长成肌肉或脊椎。

2.A segmental mass of mesoderm in the vertebrate embryo, occurring in pairs along the notochord and developing into muscles and vertebrae.

脊椎动物胚胎中胚层中的体节物质，沿脊索成对出现，后生长成肌肉或脊椎。

3.The soft anatomy of conodont shows some soft tissues including eyes, notochord, nerve cord, myomeres and caudal fin.

英国古生物学家们通过牙形石动物的软体解剖学研究，发现眼睛、脊索、神经索、肌肉组织、尾鳍等软组织；

4.Right now notochord cell disappears, pith nucleus becomes a fiber cartilage with soft and less cell gradually.

此时脊索细胞消失，髓核逐渐成为一个软而细胞较少的纤维软骨。

5.Right now the notochord cell between vertebra is added gradually much.

此时椎间的脊索细胞逐渐增多。

6.The presence of a notochord 脊索 is a defining characteristic of chordates during their embryonic development.

脊索的存在是脊索动物在胚胎发育过程中的一个定义特征。

7.In vertebrates, the notochord 脊索 is replaced by the vertebral column as development progresses.

在脊椎动物中，脊索在发育过程中被脊柱所替代。

8.Research on the notochord 脊索 helps scientists understand the evolution of the spine.

对脊索的研究帮助科学家理解脊椎的演化。

9.During the formation of the nervous system, the notochord 脊索 plays a critical role in signaling.

在神经系统的形成过程中，脊索在信号传递中起着关键作用。

10.Some species retain a functional notochord 脊索 throughout their lives.

某些物种在其一生中保留了功能性脊索。

作文

The study of embryonic development reveals fascinating insights into the evolution of complex organisms. One of the most critical structures that emerge during this process is the notochord, a flexible rod-like structure that provides support and defines the primitive axis of the developing embryo. The presence of the notochord is a defining characteristic of the phylum Chordata, which includes all vertebrates as well as some invertebrates. This structure plays a pivotal role not only in the initial stages of development but also in the overall morphology of the organism. During the early stages of embryogenesis, the notochord forms from mesodermal cells and serves as an essential scaffold for the developing nervous system. It influences the formation of the neural tube, which eventually develops into the brain and spinal cord. The signaling molecules produced by the notochord guide the differentiation of surrounding tissues, ensuring that the body plan is organized correctly. This process exemplifies the intricate interplay between various embryonic structures and how they coordinate to form a functional organism. In addition to its role in development, the notochord has significant evolutionary implications. Its presence in early chordates suggests that it may have been a crucial evolutionary innovation that allowed for greater flexibility and mobility in aquatic environments. Over time, as vertebrates evolved, the notochord was largely replaced by the vertebral column, or backbone, in many species. However, remnants of the notochord can still be found in the intervertebral discs of mammals, highlighting its enduring legacy in vertebrate anatomy. The importance of the notochord extends beyond mere structural support; it also plays a critical role in the evolutionary history of multicellular life. By examining the characteristics of the notochord across different species, scientists can trace the lineage of chordates and understand how various adaptations arose in response to environmental challenges. For instance, the transition from a simple notochord to a more complex skeletal system reflects the evolutionary pressures that favored increased size and mobility in vertebrates. Moreover, research on the notochord continues to provide valuable insights into regenerative medicine. Scientists are investigating the cellular and molecular mechanisms underlying the regeneration of the notochord in certain species, such as lampreys. Understanding these processes could lead to breakthroughs in tissue engineering and regenerative therapies for humans, particularly in repairing spinal injuries. In conclusion, the notochord is not merely a transient structure in embryonic development; it is a fundamental component that has shaped the evolution of vertebrates and continues to influence scientific research today. Its role in supporting the developing nervous system, guiding embryonic development, and providing insights into evolutionary biology underscores the significance of this remarkable structure. As we delve deeper into the mysteries of the notochord, we are reminded of the intricate connections between structure, function, and evolution in the tapestry of life.

胚胎发育的研究揭示了复杂生物进化的迷人见解。其中一个在这一过程中出现的关键结构是脊索，它是一种柔性杆状结构，提供支撑并定义了发育胚胎的原始轴线。脊索的存在是脊索动物门的一个决定性特征，该门包括所有脊椎动物以及一些无脊椎动物。这个结构不仅在发育的初始阶段发挥着关键作用，还对生物的整体形态产生影响。 在胚胎发生的早期阶段，脊索由中胚层细胞形成，并作为发育神经系统的重要支架。它影响神经管的形成，神经管最终发育成大脑和脊髓。脊索产生的信号分子指导周围组织的分化，确保身体结构正确组织。这个过程体现了各种胚胎结构之间复杂的相互作用，以及它们如何协调形成一个功能性生物体。 除了在发育中的作用外，脊索在进化上也具有重要意义。它在早期脊索动物中的存在表明，它可能是一个关键的进化创新，使得在水生环境中具有更大的灵活性和运动能力。随着时间的推移，随着脊椎动物的进化，许多物种的脊索被脊柱或脊椎骨所取代。然而，哺乳动物的椎间盘中仍然可以找到脊索的残余，突显了它在脊椎动物解剖学中的持久遗产。 脊索的重要性不仅仅在于其结构支持；它还在多细胞生命的进化历史中发挥着关键作用。通过研究不同物种中脊索的特征，科学家们可以追踪脊索动物的谱系，并理解各种适应是如何响应环境挑战而产生的。例如，从简单的脊索过渡到更复杂的骨骼系统反映了有利于脊椎动物增大体型和提高运动能力的进化压力。 此外，对脊索的研究继续为再生医学提供有价值的见解。科学家们正在研究某些物种（如七鳃鳗）中脊索再生的细胞和分子机制。理解这些过程可能会导致在组织工程和再生治疗方面的突破，特别是在修复脊髓损伤方面。 总之，脊索不仅仅是胚胎发育中的暂时结构；它是一个基本组成部分，塑造了脊椎动物的进化，并继续影响今天的科学研究。它在支持发育神经系统、引导胚胎发育以及提供对进化生物学的洞察方面的作用，凸显了这个非凡结构的重要性。当我们深入探索脊索的奥秘时，我们被提醒了结构、功能和进化在生命的织锦中的复杂联系。