allantoic sac

简明释义

尿囊

英英释义

例句

1.During dissection, we observed the allantoic sac and noted its connection to the circulatory system.

在解剖过程中，我们观察到了尿囊，并注意到它与循环系统的连接。

2.The embryo develops within the allantoic sac, which provides essential nutrients during early growth.

胚胎在尿囊中发育，这为早期生长提供了必要的营养。

3.Research on the allantoic sac has revealed its role in waste management for avian embryos.

对尿囊的研究揭示了它在鸟类胚胎废物管理中的作用。

4.The allantoic sac serves as a reservoir for metabolic waste in developing reptiles.

在发育中的爬行动物中，尿囊充当代谢废物的储存库。

5.In birds, the allantoic sac plays a crucial role in gas exchange during incubation.

在鸟类中，尿囊在孵化期间对气体交换起着至关重要的作用。

作文

The study of embryology reveals fascinating insights into the development of various organisms. One of the critical structures that play a significant role in this process is the allantoic sac. The allantoic sac is an extra-embryonic membrane that forms during the early stages of embryonic development in reptiles, birds, and mammals. It serves multiple functions, including waste storage and gas exchange, which are essential for the developing embryo's survival.In reptiles and birds, the allantoic sac is particularly important because it allows the embryo to thrive in an egg environment. As the embryo grows, it produces waste products that must be managed efficiently. The allantoic sac collects these waste products, preventing them from accumulating and potentially harming the developing organism. This feature is crucial because, unlike mammals, reptilian and avian embryos do not have direct access to maternal blood supply.Moreover, the allantoic sac also plays a vital role in respiration. It is highly vascularized, meaning it contains many blood vessels that facilitate gas exchange. Oxygen from the surrounding environment can diffuse into the allantoic sac, while carbon dioxide produced by the embryo can be expelled. This gas exchange is essential for maintaining the metabolic processes necessary for growth and development.In mammals, the role of the allantoic sac evolves as the embryo develops. Although humans and other mammals do not lay eggs, the allantoic sac still forms during early development. In this case, it contributes to the formation of the umbilical cord and plays a role in the development of the placenta. The placenta is a critical organ that connects the developing fetus to the mother, allowing for nutrient uptake, waste elimination, and gas exchange. Thus, the allantoic sac is integral to the overall reproductive strategy of mammals, facilitating a more complex form of development compared to oviparous animals.Understanding the function of the allantoic sac not only highlights the intricacies of embryonic development but also underscores the evolutionary adaptations that different species have undergone. For instance, the presence of the allantoic sac in both oviparous and viviparous organisms illustrates a common evolutionary pathway while showcasing the diversity of reproductive strategies across the animal kingdom.In conclusion, the allantoic sac is a remarkable structure that exemplifies the complexity of embryonic development. Its roles in waste management and gas exchange are crucial for the survival of embryos in various species. As we continue to study embryology, the allantoic sac will undoubtedly remain a focal point of research, providing deeper insights into the mechanisms of life and the evolution of reproductive strategies. By understanding this structure, we gain a greater appreciation for the delicate balance of life and the incredible adaptations that have arisen throughout the history of evolution.

胚胎学的研究揭示了各种生物发育过程中的迷人见解。一个在这一过程中发挥重要作用的关键结构是尿囊。尿囊是在爬行动物、鸟类和哺乳动物早期胚胎发育阶段形成的一个额外胚外膜。它具有多种功能，包括废物储存和气体交换，这对发育中的胚胎的生存至关重要。在爬行动物和鸟类中，尿囊尤其重要，因为它使胚胎能够在卵环境中茁壮成长。随着胚胎的生长，它会产生必须有效管理的废物产品。尿囊收集这些废物，防止它们积累并可能伤害发育中的生物体。这一特征至关重要，因为与哺乳动物不同，爬行动物和鸟类胚胎无法直接接触母体血液供应。此外，尿囊在呼吸中也起着重要作用。它高度血管化，意味着它包含许多血管，促进气体交换。来自周围环境的氧气可以扩散到尿囊中，而胚胎产生的二氧化碳可以被排出。这种气体交换对维持生长和发育所需的代谢过程至关重要。在哺乳动物中，尿囊的作用随着胚胎的发展而演变。尽管人类和其他哺乳动物不产卵，但在早期发育中仍然会形成尿囊。在这种情况下，它有助于脐带的形成，并在胎盘的发展中发挥作用。胎盘是一个关键器官，将发育中的胎儿与母体连接起来，允许营养物质的摄取、废物的排除和气体交换。因此，尿囊是哺乳动物整体生殖策略的重要组成部分，促进了与卵生动物相比更复杂的发育形式。理解尿囊的功能不仅突显了胚胎发育的复杂性，还强调了不同物种所经历的进化适应。例如，尿囊在卵生和胎生生物中的存在说明了一条共同的进化路径，同时展示了动物王国中生殖策略的多样性。总之，尿囊是一个非凡的结构，体现了胚胎发育的复杂性。它在废物管理和气体交换中的作用对各种物种中胚胎的生存至关重要。随着我们继续研究胚胎学，尿囊无疑将继续成为研究的焦点，为我们提供对生命机制和生殖策略演化的更深入了解。通过理解这一结构，我们对生命的微妙平衡以及在进化历史中出现的惊人适应能力有了更深刻的认识。