神经系统 The Nervous System
神 经 系 统 The Nervous System
Nervous system Central Peripheral nervous nervous system system Spinal Motor Brain Sensory cord pathways pathways Voluntary Autonomic (somatic nervous nervous system system Sympathetic Parasympathetic division aViSiOn FIGURE 51.3 The divisions of the vertebrate nervous system. The major divisions are the central and peripheral nervous systems
Introduction The nerous tissue of animals responds to stimuli within and outside of the bod Incoming information is integrated and a response is made. The nerve net response is muscle contraction or secretion by a gland. The end hydra result is the naintenance of boay functions or homeostasis
Introduction Sensory Neuron Motor Neuron Sensory Receptor Central Nervous Muscle or Gland System Effector Most animals have a central nervous system to process incoming information and direct a response. this diagram summarizes the direction of information flow
统 神经系统的基本结构 §神经元( Neuron):神经元是神经系统的基本结构和功能单位 细胞核 细胞体{线粒体 尼尔体( Nissl's bodies) 神经元 树突( dendrites) 突起 轴突(axon) 施旺细胞( Schwann cells):在外周神经系统(PNS)构成髓鞘; 少突胶质细胞( Oligodendrocytes):在中枢神经系统(CNS)构成髓鞘; 髓鞘( myelin sheath); 郎飞氏结( Ranvier nodes)
一、神经系统的基本结构 § 神经元（Neuron）：神经元是神经系统的基本结构和功能单位。 第七节 神经系统 神经元 细胞体 突 起 树突（dendrites） 轴突（axon） 细胞核 线粒体 尼尔体（Nissl’s bodies） 施旺细胞（Schwann cells）：在外周神经系统（PNS）构成髓鞘； 少突胶质细胞（Oligodendrocytes）：在中枢神经系统（CNS）构成髓鞘; 髓鞘（myelin sheath）; 郎飞氏结（Ranvier nodes）
A neuron in the retina of the eye
A neuron in the retina of the eye
Nervous tissue Sensory In all receplors Dendrites neurons, Dendrites ows Trom dendrites to axons. The cell bod contains the body nucle Axon Long Nodes Nucleus extensions body may be Nucleus surrounded elin a Axon fatty material Axon Axon that insulates terminals Porlion of and muscle cell increases the rate of electrical transmission Sensory Neuron Motor Neuron Interneuron
Nervous tissue Node of Ranvier Nucleus Mitochondria Cell body elin sheath endoplasmic Axon This is a detailed view of a motor neuron. A synapse is a tiny gap between the axon of one neuron and the dendrite of the next or between an axon and a muscle cell or gland cell
Dendrites Direction ot conduction Cell bo Axon Direction ot Dendrites FIGURE 51.2 A motor and a sensory neuron (a) The motor neuron carries impulses or"commands"to muscles and glands (effectors). (b)The sensory neuron carries information about the environment to the brain and spinal cord
Cell body Dendrites Nucleus Schwann Node of sheath Ra angier FIGURE 51.4 Structure of a typical neuron. Extending from the cell body are many dendrites, which receive information and away from the cell body. Many axons are encased by,es carry it to the cell body. A single axon transmits impuls myelin sheath, whose multiple membrane lavers facilitate a more rapid conduction of impulses. The sheath is interrupted at regular intervals by small gaps called nodes of Ranvier. In the peripheral nervous system, myeli sheaths are formed by supporting Schwann cells