Dorsal nerve cord - Wikipedia
网页The dorsal nerve cord is an anatomical feature found in chordate animals, mainly in the subphyla Vertebrata and Cephalochordata, as well as in some hemichordates. It is one of the five embryonic features unique to all chordates, the other four being a notochord, a post-anal tail, an endostyle, and pharyngeal slits.
图说神经系统(Nervous system)·脊椎动物 - 知乎 - 知乎专栏
网页神经管的前端有单个大于脑眼的 色素点 (pigment spot)，又称 眼点 (eye spot)，但无视觉作用，有人认为是退化的平衡器官，有人则以为有使脑眼免受阳光直射的作用。 摘自https://www.ck12.org/ 文昌鱼神经胚的形成. 原肠胚自前端沿背中线至胚孔的外胚层细胞下陷，形成 神经板 (neural plate)，其两侧的. 外胚层细胞同神经板脱离，向中线靠拢并完全愈合，是将来的表皮部。 神经板两侧向上隆起. 形成 神经褶 (neural fold)，在背中线汇合成留 …
Nerve cord - New World Encyclopedia
网页Nerve cord is a term that can refer to either (1) the single, hollow, fluid-filled, dorsal tract of nervous tissue that is one of the defining characteristics of chordates (dorsal nerve cord) and develops into the spinal cord and brain of vertebrates; or (2) the typically solid, ventral, double row of nerve fibers found in some phyla of ...
From nerve net to nerve ring, nerve cord and brain - Nature
网页2015年12月17日 · In vertebrates, the nerve cords correspond to the hindbrain and spinal cord. Nerve rings. In Cnidaria, concentrations of neurons and axons around the pharynx or interconnecting the rhopalia....
Spinal cord: Anatomy, structure, tracts and function | Kenhub
网页2023年11月3日 · Each segment of the spinal cord provides several pairs of spinal nerves, which exit from vertebral canal through the intervertebral foramina. There are 8 pairs of cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal pair of spinal nerves (a total of 31 pairs). Learn more about the spinal cord with our learning material.
图说神经系统(Nervous system)·无脊椎动物 - 知乎 - 知乎专栏
网页关于肌肉的神经支配了解得不多，近年来有的实验证明，腔肠动物的神经与肌肉的接触部分—— 神经肌肉突触 (neuromuscular synapses) 的超微结构和 神经肌肉连接 (neuromuscular junction)，也都与高等动物的相似。 原始神经系统——神经网. 摘自https://www.askiitians.com/biology/ 神经网 (nerve net) 是 动物界里最简单、最原始的神经系统。 一般认为它基本上是由 二极 和 多极的神经细胞 组成。 神经细胞之间的连接，经电 …
Brain, spinal cord and peripheral nervous system anatomy - Kenhub
网页2023年11月3日 · The brain generates commands for target tissues and the spinal cord acts as a conduit, connecting the brain to peripheral tissues via the PNS. The brain is divided into the cerebrum, diencephalon, cerebellum, and brainstem. The …
Neuroanatomy, Spinal Cord - StatPearls - NCBI Bookshelf
网页2023年7月24日 · The spinal cord gives rise to 31 pairs of spinal nerves, which supply mainly the trunk and the limbs. These spinal nerves are mixed nerves having a motor component that helps control all the limbs' voluntary muscles and trunk. They also have a sensory component that helps in receiving the sensory information from these areas.
The Spinal Cord & Spinal Nerves - Spine Info
网页2023年7月5日 · The spinal cord is a long, thin, cylindrical structure that runs from the base of the brain down through the vertebral column (spine or backbone) and terminates near the bottom of the lower back. It is part of the central nervous system (CNS) and is responsible for transmitting signals between the brain and the rest of the body.
Ventral nerve cord - Wikipedia
网页The ventral nerve cord is a major structure of the invertebrate central nervous system. It is the functional equivalent of the vertebrate spinal cord. [2] The ventral nerve cord coordinates neural signaling from the brain to the body and vice versa, integrating sensory input and locomotor output. [1]