unmyelinated

简明释义

英[ˌʌnˈmaɪəlɪneɪtɪd]美[ʌnˈmaɪəlɪˌneɪtɪd]

adj. 无髓鞘的

英英释义

单词用法

同义词

反义词

例句

1.Results The neurohypophysis was composed of unmyelinated nerve fibres, pituicytes and connective tissue abound in blood capillaries.

结果神经垂体主要由无髓神经纤维、垂体细胞及富含毛细血管的结缔组织组成。

2.Most ofthe fibers in the neuropil are unmyelinated, and myelinated fibers are scarce.

神经毡内无髓纤维最多，有髓纤维稀少。

3.In young and old rats, there was no significant differences of all unmyelinated fiber parameters between male and female rats.

年轻组与老年组的各项指标中雄性与雌性动物间均不存在显著的性差别。

4.Conclusion Local administration of capsaicin can produce selective destruction of unmyelinated fibers in primary afferent nerves, and can reduce the levels of SP in regions of CNV.

结论辣椒素局部神经干给药能选择性毁损初级传入神经中的无髓纤维，减少CNV区SP含量。

5.Results in the male and female rats, there was no significant decrease in the total length of unmyelinated fibers in white matter of young and aged rats.

结果雄性和雌性大鼠大脑白质无髓神经纤维总长度均无显著的老年性降低。

6.CGRP and SP have been demonstrated co-existing in sensory neuron, axons surrounding dermal blood vessels, and unmyelinated nerve endings in skin.

CGRP和SP二者在神经元、真皮血管周围神经轴突及皮肤无髓神经末梢共存。

7.The microstructure of the oriens layer of the CA3 region of the hippocampus in the control animal was composed of lots of unmyelinated fibers and less myelinated fibers under electron microscopy.

对照大鼠海马CA3区多形层内含有大量无髓纤维并见到较少的轴-树突触。

8.The microstructure of the oriens layer of the CA3 region of the hippocampus in the control animal was composed of lots of unmyelinated fibers and less myelinated fibers under electron microscopy.

对照大鼠海马CA3区多形层内含有大量无髓纤维并见到较少的轴-树突触。

9.Result: The neurohypophysis is composed of unmyelinated nerve fibers, pituicytes and connective tissue abound in blood capillaries.

结果：神经垂体主要由无髓神经纤维、垂体细胞及富含毛细血管的结缔组织构成。

10.In certain neurological conditions, the unmyelinated 无髓鞘的 nerves may become more active, leading to increased sensations.

在某些神经系统疾病中，无髓鞘的神经可能变得更加活跃，从而导致感觉增强。

11.Unlike myelinated fibers, unmyelinated 无髓鞘的 fibers do not have a protective sheath, making them more vulnerable.

与有髓鞘纤维不同，无髓鞘的纤维没有保护鞘，使它们更容易受到伤害。

12.The unmyelinated 无髓鞘的 neurons are often associated with the autonomic nervous system.

这些无髓鞘的神经元通常与自主神经系统相关。

13.The pain signals are transmitted through unmyelinated 无髓鞘的 fibers, which can result in slower response times.

疼痛信号通过无髓鞘的纤维传递，这可能导致反应时间变慢。

14.Research shows that unmyelinated 无髓鞘的 axons play a crucial role in the transmission of chronic pain.

研究表明，无髓鞘的轴突在慢性疼痛的传导中发挥着至关重要的作用。

作文

In the field of neuroscience, understanding the structure and function of nerve fibers is essential for grasping how the nervous system operates. One crucial aspect of nerve fibers is whether they are myelinated or unmyelinated. Myelination refers to the presence of a fatty sheath, known as myelin, that wraps around the axons of certain neurons. This myelin sheath acts as an insulator, allowing electrical impulses to transmit more rapidly along the nerve fibers. In contrast, unmyelinated fibers lack this protective covering, which significantly influences their conduction velocity and overall functionality.The differences between myelinated and unmyelinated fibers can be observed in various types of neural pathways. For instance, myelinated fibers are predominantly found in areas of the nervous system where speed is essential, such as in motor neurons and sensory pathways that require quick reflexes. These fibers can conduct impulses at speeds of up to 120 meters per second due to the saltatory conduction mechanism, where the impulse jumps from one node of Ranvier (gaps in the myelin sheath) to another.On the other hand, unmyelinated fibers are typically slower, conducting impulses at a rate of about 1 meter per second. They are often found in regions where rapid transmission is not as critical, such as in the autonomic nervous system, which controls involuntary bodily functions. The slower conduction speed of unmyelinated fibers can be attributed to the absence of myelin, which means that the entire length of the axon must be depolarized sequentially, rather than allowing for the jumping action seen in myelinated fibers.One significant implication of having unmyelinated fibers is their role in pain perception. Many pain fibers are unmyelinated, which contributes to the slower onset of chronic pain signals compared to the sharp, immediate pain transmitted by myelinated fibers. This distinction is crucial in understanding how different types of pain are processed in the body and can influence treatment approaches for pain management.Moreover, the presence of unmyelinated fibers is vital in certain physiological processes. For example, they play a role in the regulation of blood pressure and digestion through the autonomic nervous system. The slower signaling provided by unmyelinated fibers allows for a more sustained response, which is necessary for maintaining homeostasis in these systems.In summary, the distinction between myelinated and unmyelinated fibers is fundamental in neuroscience. While myelinated fibers allow for rapid signal transmission essential for reflexes and quick responses, unmyelinated fibers serve important roles in slower, more sustained processes within the body. Understanding these differences helps us appreciate the complexity of the nervous system and its ability to adapt to various physiological demands. As research continues to explore the intricacies of neuronal communication, the significance of both myelinated and unmyelinated fibers will undoubtedly remain a pivotal area of study in neuroscience.

在神经科学领域，理解神经纤维的结构和功能对于掌握神经系统的运作至关重要。神经纤维的一个关键方面是它们是否有髓鞘（myelinated）或无髓鞘（unmyelinated）。髓鞘是指包裹在某些神经元轴突周围的脂肪鞘，称为髓鞘。这个髓鞘起到绝缘体的作用，使电信号能够更快速地沿着神经纤维传导。相反，无髓鞘纤维缺乏这种保护性覆盖，这显著影响了它们的传导速度和整体功能。髓鞘纤维和无髓鞘纤维之间的差异可以在各种类型的神经通路中观察到。例如，髓鞘纤维主要存在于神经系统中的速度至关重要的区域，如运动神经元和需要快速反射的感觉通路。这些纤维可以以每秒高达120米的速度传导冲动，这是由于跳跃传导机制的作用，即冲动从一个朗飞结（髓鞘间隙）跳跃到另一个。另一方面，无髓鞘纤维通常较慢，传导冲动的速度约为每秒1米。它们通常出现在速度不那么关键的区域，例如控制非自愿身体功能的自主神经系统。无髓鞘纤维的较慢传导速度可以归因于缺乏髓鞘，这意味着整个轴突的长度必须依次去极化，而不是像髓鞘纤维那样允许跳跃式的动作。拥有无髓鞘纤维的一个重要意义在于它们在疼痛感知中的作用。许多疼痛纤维是无髓鞘的，这导致慢性疼痛信号的发作速度比髓鞘纤维传递的尖锐、即时疼痛要慢。这一区别对于理解不同类型的疼痛在身体中的处理方式至关重要，并可能影响疼痛管理的治疗方法。此外，无髓鞘纤维在某些生理过程中也发挥着重要作用。例如，它们通过自主神经系统在血压和消化的调节中起作用。无髓鞘纤维提供的较慢信号传导允许更持久的反应，这对于维持这些系统的稳态是必要的。总之，髓鞘纤维和无髓鞘纤维之间的区别在神经科学中是基础性的。虽然髓鞘纤维允许快速信号传导，这对反射和快速反应至关重要，但无髓鞘纤维在身体内的较慢、更加持久的过程中的重要角色。理解这些差异帮助我们欣赏神经系统的复杂性及其适应各种生理需求的能力。随着研究继续探索神经通信的复杂性，髓鞘和无髓鞘纤维的意义无疑将继续成为神经科学研究的关键领域。