Nerve

A nerve is an enclosed, cable-like bundle of nerve fibres (called axons) in the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons to peripheral organs. Each axon within the nerve is the tail of a neuron, and other supportive cells such as Schwann cells exist. Schwann cells that coat the axons in myelin. 

The nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body.[8] In vertebrates it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor or efferent nerves, while those nerves that transmit information from the body to the CNS are called sensory or afferent. Spinal nerves serve both functions and are called mixed nerves. The PNS is divided into three separate subsystems, the somatic, autonomic, and enteric nervous systems. Somatic nerves mediate voluntary movement. 

神经是外周神经系统中一种封闭的、电缆状的神经纤维束(称为轴突)。神经为电化学神经冲动提供了一条共同的通路，电化学神经冲动沿着每个轴突传递到周围器官。神经内的每个轴突都是神经元的尾部，其他支持细胞如雪旺细胞也存在。髓磷脂中覆盖轴突的雪旺细胞。 

神经系统是通过向身体的不同部位传递信号来协调其动作的动物的一部分。[8]在脊椎动物中，它由两个主要部分组成，中枢神经系统（CNS）和周围神经系统（PNS）。中枢神经系统由脑和脊髓组成。 PNS主要由神经组成，神经是长纤维或轴突的封闭束，其将CNS连接到身体的每个其他部分。 传递来自大脑的信号的神经被称为运动或传出神经，而那些将信息从身体传递到CNS的神经被称为感觉或传入神经。脊神经起到两种功能，称为混合神经。 PNS分为三个独立的子系统，即躯体神经系统，自主神经系统和肠神经系统。躯体神经介导自愿运动。