Ch14 The Autonomic Nervous System
自主神经系统
本页英文内容取自：经典教材医学生理学（第三版） (Medical Physiology, 3rd Edtion, Walter F Boron, published in 2016)
中文内容由 BH1RBH (Jack Tan) 粗糙翻译
蓝色 【注】 后内容为 BH1RBH (Jack Tan) 所加之注释
When we are awake, we are constantly aware of sensory input from our external environment, and we consciously plan how to react to it. When we are asleep, the nervous system has a variety of mechanisms to dissociate cortical function from sensory input and somatic motor output. Among these mechanisms are closing the eyes, blocking the transmission of sensory impulses to the cortex as they pass through the thalamus, and effecting a nearly complete paralysis of skeletal muscles during rapid eye movement (REM) sleep to keep us from physically acting out our dreams.
当我们清醒时，我们会不断意识到来自外部环境的感官输入，并有意识地计划如何应对它。当我们睡着时，神经系统有多种机制可以将皮层功能与感觉输入和躯体运动输出分离。这些机制包括闭上眼睛，阻止感觉冲动通过丘脑时向皮层的传递，以及在快速眼动 （REM） 睡眠期间导致骨骼肌几乎完全麻痹，以防止我们身体上表演我们的梦。
The conscious and discontinuous nature of cortical brain function stands in sharp contrast with those parts of the nervous system that are responsible for control of our internal environment. These “autonomic” processes never stop attending to the wide range of metabolic, cardiopulmonary, and other visceral requirements of our body. Autonomic control continues whether we are awake and attentive, preoccupied with other activities, or asleep. While we are awake, we are unaware of most visceral sensory input, and we avoid any conscious effort to act on it unless it induces distress. In most cases, we have no awareness of motor commands to the viscera, and most individuals can exert voluntary control over motor output to the viscera only in minor ways. Consciousness and memory are frequently considered the most important functions of the human nervous system, but it is the visceral control system—including the autonomic nervous system (ANS)—that makes life and higher cortical function possible.
大脑皮层功能的有意识和不连续性质与神经系统中负责控制我们内部环境的部分形成鲜明对比。这些“自主神经”过程从未停止关注我们身体的各种代谢、心肺和其他内脏需求。无论我们是清醒和专心、全神贯注于其他活动还是睡着，自主神经控制都会继续。当我们清醒时，我们不知道大多数本能的感官输入，除非它引起痛苦，否则我们会避免任何有意识的努力去采取行动。在大多数情况下，我们没有意识到对内脏的运动命令，大多数人只能以微小的方式对内脏的运动输出进行自主控制。意识和记忆通常被认为是人类神经系统最重要的功能，但正是内脏控制系统——包括自主神经系统 （ANS）——使生命和高级皮质功能成为可能。
We have a greater understanding of the physiology of the ANS than of many other parts of the nervous system, largely because it is reasonably easy to isolate peripheral neurons and to study them. As a result of its accessibility, the ANS has served as a key model system for the elucidation of many principles of neuronal and synaptic function.
我们对自主神经系统比对神经系统的许多其他部分的生理更了解，这主要是因为分离周围神经元并对其进行研究相当容易。由于其可访问性，ANS 已成为阐明神经元和突触功能的许多原理的关键模型系统。
目录 |
1 本能控制系统的组织
ORGANIZATION OF THE VISCERAL CONTROL SYSTEM
1.1 自主神经系统有交感神经、副交感神经和肠道神经
The autonomic nervous system has sympathetic, parasympathetic, and enteric divisions
Output from the central nervous system (CNS) travels along two anatomically and functionally distinct pathways: the somatic motor neurons, which innervate striated skeletal muscle; and the autonomic motor neurons, which innervate smooth muscle, cardiac muscle, secretory epithelia, and glands. All viscera are richly supplied by efferent axons from the ANS that constantly adjust organ function.
中枢神经系统 （CNS） 的输出沿着两条解剖学和功能上不同的途径传播：躯体运动神经元，支配横纹骨骼肌；以及自主运动神经元，支配平滑肌、心肌、分泌上皮和腺体。所有内脏都由来自自主神经系统的传出轴突丰富地提供，这些轴突不断调整器官功能。
The autonomic nervous system (from the Greek for “selfgoverning,” functioning independently of the will) was first defined by Langley in 1898 as including the local nervous system of the gut and the efferent neurons innervating glands and involuntary muscle. Thus, this definition of the ANS includes only efferent neurons and enteric neurons. Since that time, it has become clear that the efferent ANS cannot easily be dissociated from visceral afferents as well as from those parts of the CNS that control the output to the ANS and those that receive interoceptive input. N14-1 This larger visceral control system monitors afferents from the viscera and the rest of the body, compares this input with current and anticipated needs, and controls output to the body’s organ systems.
自主神经系统（来自希腊语，意为“自我管理”，独立于意志运作）由 Langley 于 1898 年首次定义为包括肠道的局部神经系统以及支配腺体和非自主肌肉的传出神经元。因此，ANS 的这个定义仅包括传出神经元和肠道神经元。从那时起，很明显，传出的 ANS 不能轻易地与内脏传入神经以及控制 ANS 输出的 CNS 部分和接收内感受输入的部分分离[N14-1]。 这个较大的内脏控制系统监测来自内脏和身体其他部位的传入神经，将此输入与当前和预期的需求进行比较，并控制对身体器官系统的输出。
The ANS has three divisions: sympathetic, parasympathetic, and enteric. The sympathetic and parasympathetic divisions of the ANS are the two major efferent pathways controlling targets other than skeletal muscle (Fig. 14-1). Each innervates target tissue by a two-synapse pathway. The cell bodies of the first neurons lie within the CNS. These preganglionic neurons are found in columns of cells in the brainstem and spinal cord and send axons out of the CNS to make synapses with postganglionic neurons in peripheral ganglia interposed between the CNS and their target cells. Axons from these postganglionic neurons then project to their targets. The sympathetic and parasympathetic divisions can act independently of each other. However, in general, they work synergistically to control visceral activity and often act in opposite ways, like an accelerator and brake to regulate visceral function. An increase in output of the sympathetic division occurs under conditions such as stress, anxiety, physical activity, fear, or excitement, whereas parasympathetic output increases during sedentary activity, eating, or other “vegetative” behavior.
自主神经系统 (ANS) 分为三个部分：交感神经、副交感神经和肠道。ANS 的交感神经和副交感神经分支是控制骨骼肌以外目标的两个主要传出途径（图 14-1）。每个都通过双突触途径支配靶组织。第一个神经元的细胞体位于 CNS 内。这些节前神经元存在于脑干和脊髓的细胞柱中，并将轴突从 CNS 发送出去，与位于 CNS 与其靶细胞之间的外周神经节中的节后神经元形成突触。然后，来自这些节后神经元的轴突投射到它们的目标。交感神经和副交感神经部门可以彼此独立地行动。然而，一般来说，它们协同作用以控制内脏活动，并且通常以相反的方式发挥作用，例如加速器和制动器来调节内脏功能。交感神经输出的增加发生在压力、焦虑、体力活动、恐惧或兴奋等条件下，而副交感神经输出增加发生在久坐活动、进食或其他“植物人”行为期间。
The enteric division of the ANS is a collection of afferent neurons, interneurons, and motor neurons that form networks of neurons called plexuses (from the Latin “to braid”) that surround the gastrointestinal (GI) tract. It can function as a separate and independent nervous system, but it is normally controlled by the CNS through sympathetic and parasympathetic fibers.
ANS 的肠道分支是传入神经元、中间神经元和运动神经元的集合，它们形成围绕胃肠道 （GI） 的神经元网络，称为神经丛（来自拉丁语“辫子”）。它可以作为一个独立且独立的神经系统发挥作用，但它通常由 CNS 通过交感神经和副交感神经纤维控制。
1.2 交感神经节前神经元起源于脊髓节段 T1 至 L3，与椎旁或椎前神经节中的节后神经元形成突触
Sympathetic preganglionic neurons originate from spinal segments T1 to L3 and synapse with postganglionic neurons in paravertebral or prevertebral ganglia
Preganglionic Neurons The cell bodies of preganglionic sympathetic motor neurons are located in the thoracic and upper lumbar spinal cord between levels T1 and L3. At these spinal levels, autonomic neurons lie in the intermediolateral cell column, or lateral horn, between the dorsal and ventral horns (Fig. 14-2). Axons from preganglionic sympathetic neurons exit the spinal cord through the ventral roots along with axons from somatic motor neurons. After entering the spinal nerves, sympathetic efferents diverge from somatic motor axons to enter the white rami communicantes. These rami, or branches, are white because most preganglionic sympathetic axons are myelinated.
节前神经元 节前交感神经运动神经元的细胞体位于 T1 和 L3 水平之间的胸椎和上腰椎脊髓中。在这些脊柱水平上，自主神经元位于背角和腹角之间的中间外侧细胞柱或外侧角中（图 14-2）。来自节前交感神经元的轴突与来自体细胞运动神经元的轴突一起通过腹根离开脊髓。进入脊神经后，交感神经传出物从躯体运动轴突分化进入白色支交通。这些支或分支是白色的，因为大多数节前交感神经轴突都是有髓的。
Paravertebral Ganglia Axons from preganglionic neurons enter the nearest sympathetic paravertebral ganglion through a white ramus. These ganglia lie adjacent to the vertebral column. Although preganglionic sympathetic fibers emerge only from levels T1 to L3, the chain of sympathetic ganglia extends all the way from the upper part of the neck to the coccyx, where the left and right sympathetic chains merge in the midline and form the coccygeal ganglion. In general, one ganglion is positioned at the level of each spinal root, but adjacent ganglia are fused in some cases. The most rostral ganglion, the superior cervical ganglion, arises from fusion of C1 to C4 and supplies the head and neck. The next two ganglia are the middle cervical ganglion, which arises from fusion of C5 and C6, and the inferior cervical ganglion (C7 and C8), which is usually fused with the first thoracic ganglion to form the stellate ganglion. Together, the middle cervical and stellate ganglia, along with the upper thoracic ganglia, innervate the heart, lungs, and bronchi. The remaining paravertebral ganglia supply organs and portions of the body wall in a segmental fashion.
椎旁神经节 来自节前神经元的轴突通过白色支进入最近的交感椎旁神经节。这些神经节位于脊柱附近。虽然节前交感神经纤维仅出现在 T1 至 L3 水平，但交感神经节链从颈部上部一直延伸到尾骨，左右交感神经链在中线汇合，形成尾骨神经节。一般来说，一个神经节位于每个脊髓根的水平，但在某些情况下，相邻的神经节会融合。最前端的神经节，即颈上神经节，由 C1 和 C4 融合产生，供应头部和颈部。接下来的两个神经节是颈中神经节，它是由 C5 和 C6 融合产生的，以及下颈神经节（C7 和 C8），通常与第一胸神经节融合形成星状神经节。中颈神经节和星状神经节以及上胸神经节一起支配心脏、肺和支气管。剩余的椎旁神经节以节段方式供应器官和体壁的一部分。
After entering a paravertebral ganglion, a preganglionic sympathetic axon has one or more of three fates. It may (1) synapse within that segmental paravertebral ganglion, (2) travel up or down the sympathetic chain to synapse within a neighboring paravertebral ganglion, or (3) enter the greater or lesser splanchnic nerve to synapse within one of the ganglia of the prevertebral plexus.
进入椎旁神经节后，节前交感神经轴突具有三种命运中的一种或多种。它可能 （1） 在该节段性椎旁神经节内形成突触，（2） 沿交感神经链向上或向下移动到邻近椎旁神经节内的突触，或 （3） 进入较大或较小的内脏神经到椎前丛神经节之一内的突触。
Prevertebral Ganglia The prevertebral plexus lies in front of the aorta and along its major arterial branches and includes the prevertebral ganglia and interconnected fibers (Fig. 14-3). The major prevertebral ganglia are named according to the arteries that they are adjacent to and include the celiac, superior mesenteric, aorticorenal, and inferior mesenteric ganglia. Portions of the prevertebral plexus extend down the major arteries and contain other named and unnamed ganglia and plexuses of nerve fibers, which altogether make up a dense and extensive network of sympathetic neuron cell bodies and nerve fibers.
椎前神经节 椎前丛位于主动脉前方及其主要动脉分支，包括椎前神经节和互连的纤维（图 14-3）。主要椎前神经节根据它们相邻的动脉命名，包括腹腔、肠系膜上神经节、主动脉核心神经节和肠系膜下神经节。椎前丛的一部分向下延伸到主要动脉，并包含其他命名和未命名的神经节和神经丛，它们共同构成了交感神经元细胞体和神经纤维的密集而广泛的网络。
Each preganglionic sympathetic fiber synapses on many postganglionic sympathetic neurons that are located within one or several nearby paravertebral or prevertebral ganglia. It has been estimated that each preganglionic sympathetic neuron branches and synapses on as many as 200 postganglionic neurons, which enables the sympathetic output to have more widespread effects. However, any impulse arriving at its target end organ has only crossed a single synapse between the preganglionic and postganglionic sympathetic neurons.
每个节前交感神经纤维突触位于位于附近一个或多个椎旁神经节或椎前神经节内的许多节后交感神经元上。据估计，每个节前交感神经元在多达 200 个节后神经元上分支和突触，这使得交感神经输出能够产生更广泛的影响。然而，任何到达其目标终末器官的冲动都只穿过了节前和节后交感神经元之间的单个突触。
Postganglionic Neurons The cell bodies of postganglionic sympathetic neurons that are located within paravertebral ganglia send out their axons through the nearest gray rami communicantes, which rejoin the spinal nerves (see Fig. 14-2). These rami are gray because most postganglionic axons are unmyelinated. Because preganglionic sympathetic neurons are located only in the thoracic and upper lumbar spinal segments (T1 to L3), white rami are found only at these levels (Fig. 14-4, left panel). However, because each sympathetic ganglion sends out postganglionic axons, gray rami are present at all spinal levels from C2 or C3 to the coccyx. Postganglionic sympathetic axons from paravertebral and prevertebral ganglia travel to their target organs within other nerves or by traveling along blood vessels. Because the paravertebral and prevertebral sympathetic ganglia lie near the spinal cord and thus relatively far from their target organs, the postganglionic axons of the sympathetic division tend to be long. On their way to reach their targets, some postganglionic sympathetic axons travel through parasympathetic terminal ganglia or cranial nerve ganglia without synapsing[N14-2].
节后神经元 位于椎旁神经节内的节后交感神经元的细胞体通过最近的灰色交感支发出轴突，这些支重新加入脊神经（见图 14-2）。这些支是灰色的，因为大多数节后轴突是无髓的。因为节前交感神经元仅位于胸椎和上腰椎段（T1 到 L3），所以白色支仅在这些水平上发现（图 14-4，左图）。然而，由于每个交感神经节都会发出节后轴突，因此从 C2 或 C3 到尾骨的所有脊柱水平都存在灰色支。来自椎旁和椎前神经节的节后交感神经轴突通过其他神经或沿血管行进到其目标器官。因为椎旁和椎前交感神经节位于脊髓附近，因此离它们的目标器官相对较远，所以交感神经支的节后轴突往往很长。在到达目标的途中，一些节后交感神经轴突穿过副交感神经末梢神经节或颅神经节，没有突触[N14-2]。
Parasympathetic preganglionic neurons originate from the brainstem and sacral spinal cord and synapse with postganglionic neurons in ganglia located near target organs
副交感神经节前神经元起源于脑干和骶脊髓，与位于靶器官附近神经节的节后神经元形成突触
The cell bodies of preganglionic parasympathetic neurons are located in the medulla, pons, and midbrain and in the S2 through S4 levels of the spinal cord (see Fig. 14-4, right panel). Thus, unlike the sympathetic— or thoracolumbar—division, whose preganglionic cell bodies are in the thoracic and lumbar spinal cord, the parasympathetic—or craniosacral—division’s preganglionic cell bodies are cranial and sacral. The preganglionic parasympathetic fibers originating in the brain distribute with four cranial nerves: the oculomotor nerve (CN III), the facial nerve (CN VII), the glossopharyngeal nerve (CN IX), and the vagus nerve (CN X). The preganglionic parasympathetic fibers originating in S2 through S4 distribute with the pelvic splanchnic nerves.
节前副交感神经元的细胞体位于延髓、脑桥和中脑以及脊髓的 S2 至 S4 水平（见图 14-4，右图）。因此，与交感神经或胸腰椎支不同，其节前细胞体位于胸腰脊髓中，副交感神经或颅骶支的节前细胞体是颅骨和骶骨。起源于大脑的节前副交感神经纤维分布有四条颅神经：动眼神经 （CN III）、面神经 （CN VII）、舌咽神经 （CN IX） 和迷走神经 （CN X）。起源于 S2 至 S4 的节前副交感神经纤维与盆腔内脏神经分布。
Postganglionic parasympathetic neurons are located in terminal ganglia that are more peripherally located and more widely distributed than are the sympathetic ganglia. Terminal ganglia often lie within the walls of their target organs. Thus, in contrast to the sympathetic division, postganglionic fibers of the parasympathetic division are short.In some cases, individual postganglionic parasympathetic neurons are found in isolation or in scattered cell groups rather than in encapsulated ganglia.
节后副交感神经元位于末端神经节中，与交感神经节相比，末端神经节的位置更外围，分布更广泛。末端神经节通常位于其靶器官的壁内。因此，与交感神经支相反，副交感神经支的节后纤维很短。在某些情况下，单个节后副交感神经元孤立或分散在细胞群中，而不是在包膜神经节中发现。
Cranial Nerves III, VII, and IX The preganglionic parasympathetic neurons that are distributed with CN III, CN VII, and CN IX originate in three groups of nuclei.
颅神经 III、VII 和 IX 与 CN III、CN VII 和 CN IX 分布的节前副交感神经元起源于三组核。
1. The Edinger-Westphal nucleus is a subnucleus of the oculomotor complex in the midbrain (Fig. 14-5). Parasympathetic neurons in this nucleus travel in the oculomotor nerve (CN III) and synapse onto postganglionic neurons in the ciliary ganglion (see Fig. 14-4, right panel). The postganglionic fibers project to two smooth muscles of the eye: the constrictor muscle of the pupil and the ciliary muscle, which controls the shape of the lens (see Fig. 15-6).
1. Edinger-Westphal 核是中脑动眼神经复合体的亚核（图 14-5）。该核中的副交感神经元在动眼神经 （CN III） 中移动，并突触到达睫状神经节中的节后神经元（见图 14-4，右图）。节后纤维投射到眼睛的两块平滑肌：瞳孔收缩肌和睫状肌，它控制晶状体的形状（见图 15-6）。
2. The superior salivatory nucleus is in the rostral medulla (see Fig. 14-5) and contains parasympathetic neurons that project, through a branch of the facial nerve (CN VII), to the pterygopalatine ganglion (see Fig. 14-4, right panel). The postganglionic fibers supply the lacrimal glands, which produce tears. Another branch of the facial nerve carries preganglionic fibers to the submandibular ganglion. The postganglionic fibers supply two salivary glands, the submandibular and sublingual glands.
2. 上唾液核位于延髓喙部（见图 14-5），包含副交感神经元，这些神经元通过面神经的一个分支 （CN VII） 投射到翼腭神经节（见图 14-4，右图）。节后纤维供应泪腺，泪腺产生撕裂。面神经的另一个分支将节前纤维输送到下颌下神经节。节后纤维供应两个唾液腺，即下颌下腺和舌下腺。
3. The inferior salivatory nucleus and the rostral part of the nucleus ambiguus in the rostral medulla (see Fig. 14-5) contain parasympathetic neurons that project through the glossopharyngeal nerve (CN IX) to the otic ganglion (see Fig. 14-4, right panel). The postganglionic fibers supply a third salivary gland, the parotid gland.
3. 喙延髓中下唾液核和模糊核的喙部（见图 14-5）包含通过舌咽神经 （CN IX） 投射到耳神经节的副交感神经元（见图 14-4，右图）。节后纤维供应第三个唾液腺，即腮腺。
Cranial Nerve X Most parasympathetic output occurs through the vagus nerve (CN X). Cell bodies of vagal preganglionic parasympathetic neurons are found in the medulla within the nucleus ambiguus and the dorsal motor nucleus of the vagus (see Fig. 14-5). This nerve supplies parasympathetic innervation to all the viscera of the thorax and abdomen, including the GI tract between the pharynx and distal end of the colon (see Fig. 14-4, right panel). Among other effects, electrical stimulation of the nucleus ambiguus results in contraction of striated muscle in the pharynx, larynx, and upper esophagus due to activation of somatic motor neurons (not autonomic), as well as slowing of the heart due to activation of vagal preganglionic parasympathetic neurons. Stimulation of the dorsal motor nucleus of the vagus induces many effects in the viscera, including initiation of secretion of gastric acid, insulin, and glucagon. Preganglionic parasympathetic fibers of the vagus nerve join the esophageal, pulmonary, and cardiac plexuses and travel to terminal ganglia that are located within their target organs.
颅神经 X 大多数副交感神经输出通过迷走神经 （CN X） 发生。迷走神经节前副交感神经元的细胞体位于迷走神经模糊核和背侧运动核内的延髓中（见图 14-5）。该神经为胸部和腹部的所有内脏提供副交感神经支配，包括咽部和结肠远端之间的胃肠道（见图 14-4，右图）。除其他作用外，由于体细胞运动神经元（非自主神经）的激活，对模糊核的电刺激导致咽部、喉部和食管上部的横纹肌收缩，以及由于迷走神经节前副交感神经元的激活而导致心脏减慢。刺激迷走神经背侧运动核在内脏中引起许多影响，包括开始分泌胃酸、胰岛素和胰高血糖素。迷走神经的节前副交感神经纤维加入食管丛、肺丛和心脏丛，并行进到位于其靶器官内的末端神经节。
Sacral Nerves The cell bodies of preganglionic parasympathetic neurons in the sacral spinal cord (S2 to S4) are located in a position similar to that of the preganglionic sympathetic neurons—although they do not form a distinct intermediolateral column. Their axons leave through ventral roots and travel with the pelvic splanchnic nerves to their terminal ganglia in the descending colon and rectum (see p. 862), as well as to the bladder (see pp. 736–737) and the reproductive organs of the male (see p. 1104) and female (see p. 1127).
骶神经 骶脊髓（S2 至 S4）中节前副交感神经元的细胞体位于与节前交感神经元相似的位置——尽管它们不形成明显的中间外侧柱。它们的轴突从腹根离开，与盆腔内脏神经一起移动到降结肠和直肠的末端神经节（见第 862 页），以及膀胱（见第 736-737 页）和男性（见第 1104 页）和女性（见第 1127 页）的生殖器官。
1.3 内脏控制系统也有一个重要的传入肢体
The visceral control system also has an important afferent limb
All internal organs are densely innervated by visceral afferents. Some of these receptors monitor nociceptive (painful) input. Others are sensitive to a variety of mechanical and chemical (physiological) stimuli, including stretch of the heart, blood vessels, and hollow viscera, as well as PCO2, PO2, pH, blood glucose, and temperature of the skin and internal organs. Many visceral nociceptive fibers travel in sympathetic nerves (blue projections in Fig. 14-2). Most axons from physiological receptors travel with parasympathetic fibers. As is the case with somatic afferents (see p. 271), the cell bodies of visceral afferent fibers are located within the dorsal root ganglia or cranial nerve ganglia (e.g., nodose and petrosal ganglia). Ninety percent of these visceral afferents are unmyelinated.
所有内脏器官都由内脏传入神经密集支配。其中一些受体监控伤害性（痛苦）输入。其他对各种机械和化学（生理）刺激敏感，包括心脏伸展、血管和空腔内脏，以及 PCO2、PO2、pH、血糖以及皮肤和内脏器官的温度。许多内脏伤害性纤维在交感神经中行进（图 14-2 中的蓝色投影）。来自生理受体的大多数轴突与副交感神经纤维一起移动。与体细胞传入神经一样（见第 271 页），内脏传入纤维的细胞体位于背根神经节或颅神经节（例如，结节和岩神经节）内。这些内脏传入神经中有 90% 是无髓的。
The largest concentration of visceral afferent axons can be found in the vagus nerve, which carries non-nociceptive afferent input to the CNS from all viscera of the thorax and abdomen. Most fibers in the vagus nerve are afferents, even though all parasympathetic preganglionic output (i.e., efferents) to the abdominal and thoracic viscera also travels in the vagus nerve. Vagal afferents, whose cell bodies are located in the nodose ganglion, carry information about the distention of hollow organs (e.g., blood vessels, cardiac chambers, stomach, bronchioles), blood gases (e.g., PO2, PCO2, pH from the aortic bodies), and body chemistry (e.g., glucose concentration) to the medulla.
内脏传入轴突的最大集中体可以在迷走神经中找到，迷走神经将非伤害性传入输入从胸部和腹部的所有内脏传递到 CNS。迷走神经中的大多数纤维是传入神经，即使所有副交感神经节前输出（即传出神经）到腹部和胸部内脏也都在迷走神经中移动。迷走神经传入神经的细胞体位于结节神经节中，将有关空心器官（例如血管、心腔、胃、细支气管）、血气（例如主动脉体的 PO2、PCO2、pH 值）和身体化学成分（例如葡萄糖浓度）的膨胀信息带到髓质。
Internal organs also have nociceptive receptors that are sensitive to excessive stretch, noxious chemical irritants, and very large decreases in pH. In the CNS, this visceral pain input is mapped (see pp. 400–401) viscerotopically at the level of the spinal cord because most visceral nociceptive fibers travel with the sympathetic fibers and enter the spinal cord at a specific segmental level along with a spinal nerve (see Fig. 14-2). This viscerotopic mapping is also present in the brainstem but not at the level of the cerebral cortex. Thus, awareness of visceral pain is not usually localized to a specific organ but is instead “referred” to the dermatome (see p. 273) that is innervated by the same spinal nerve. This referred pain results from lack of precision in the central organization of visceral pain pathways. Thus, you know that the pain is associated with a particular spinal nerve, but you do not know where the pain is coming from (i.e., from the skin or a visceral organ). For example, nociceptive input from the left ventricle of the heart is referred to the left T1 to T5 dermatomes and leads to discomfort in the left arm and left side of the chest, whereas nociceptive input from the diaphragm is referred to the C3 to C5 dermatomes and is interpreted as pain in the shoulder. This visceral pain is often felt as a vague burning or pressure sensation.
内部器官也有伤害性受体，对过度拉伸、有害化学刺激物和 pH 值大幅下降敏感。在 CNS 中，这种内脏疼痛输入在脊髓水平的内脏位上映射（见第 400-401 页），因为大多数内脏伤害性纤维与交感神经一起移动，并与脊神经一起在特定节段水平进入脊髓（见图 14-2）。这种内脏映射也存在于脑干中，但不存在于大脑皮层的水平。因此，对内脏疼痛的意识通常不局限于特定器官，而是“指代”由同一脊神经支配的皮节（见第 273 页）。这种牵涉痛是由于内脏疼痛通路的中心组织缺乏精确性造成的。因此，您知道疼痛与特定的脊神经有关，但您不知道疼痛来自哪里（即来自皮肤或内脏器官）。例如，来自心脏左心室的伤害性输入被称为左 T1 到 T5 皮节，并导致左臂和胸部左侧的不适，而来自横膈膜的伤害性输入被称为 C3 到 C5 皮节，并被解释为肩部疼痛。这种内脏疼痛通常表现为隐约的灼热感或压迫感。
1.4 肠部是胃肠道的一个自给自足的神经系统，接收交感神经和副交感神经的输入
The enteric division is a self-contained nervous system of the GI tract and receives sympathetic and parasympathetic input
The enteric nervous system (ENS) is a collection of nerve plexuses that surround the GI tract, including the pancreas and biliary system. Although it is entirely peripheral, the ENS receives input from the sympathetic and parasympathetic divisions of the ANS. The ENS is estimated to contain >100 million neurons, including afferent neurons, interneurons, and efferent postganglionic parasympathetic neurons. Enteric neurons contain many different neurotransmitters and neuromodulators. Thus, not only does the total number of neurons in the enteric division exceed that of the spinal cord, but the neurochemical complexity of the ENS also approaches that of the CNS. The anatomy of the ENS as well as its role in controlling GI function is discussed in Chapter 41.
肠道神经系统 （ENS） 是围绕胃肠道的神经丛的集合，包括胰腺和胆道系统。虽然它完全是外围的，但 ENS 接收来自 ANS 的交感神经和副交感神经部门的输入。据估计，ENS 包含 > 1 亿个神经元，包括传入神经元、中间神经元和传出节后副交感神经元。肠道神经元包含许多不同的神经递质和神经调节剂。因此，不仅肠道分裂的神经元总数超过脊髓的神经元总数，而且 ENS 的神经化学复杂性也接近 CNS 的神经化学复杂性。ENS 的解剖结构及其在控制 GI 功能中的作用将在第 41 章中讨论。
The plexuses of the ENS are a system of ganglia sandwiched between the layers of the gut and connected by a dense meshwork of nerve fibers. The myenteric or Auerbach’s plexus (Fig. 14-6) lies between the outer longitudinal and the inner circular layers of smooth muscle, whereas the submucosal or Meissner’s plexus lies between the inner circular layer of smooth muscle and the most internal layer of smooth muscle, the muscularis mucosae (see Fig. 41-3). In the intestinal wall, the myenteric plexus is involved primarily in the control of motility, whereas the submucosal plexus is involved in the control of ion and fluid transport. Both the myenteric and the submucosal plexuses receive preganglionic parasympathetic innervation from the vagus nerve (or sacral nerves in the case of the distal portion of colon and rectum). Thus, in one sense, the enteric division is homologous to a large and complex parasympathetic terminal ganglion. The other major input to the ENS is from postganglionic sympathetic neurons. Thus, the ENS can be thought of as “postganglionic” or as a “terminal organ” with respect to the parasympathetic division and “post-postganglionic” with respect to the sympathetic division. Input from both the sympathetic and parasympathetic divisions modulates the activity of the ENS, but the ENS can by and large function normally without extrinsic input. The isolated ENS can respond appropriately to local stimuli and control most aspects of gut function, including initiating peristaltic activity in response to gastric distention, controlling secretory and absorptive functions, and triggering biliary contractions (Box 14-1).
ENS 的神经丛是夹在肠道各层之间的神经节系统，由密集的神经纤维网连接。肌间神经丛或 Auerbach 神经丛（图 14-6）位于平滑肌的外纵层和内环层之间，而粘膜下神经丛或 Meissner 神经丛位于平滑肌的内环层和平滑肌最内层之间，即粘膜肌层（见图 41-3）。在肠壁中，肌间神经丛主要参与运动的控制，而粘膜下丛则参与离子和液体运输的控制。肌间神经丛和粘膜下丛都接受来自迷走神经（或结肠和直肠远端部分的骶神经）的节前副交感神经支配。因此，从某种意义上说，肠道支与一个大而复杂的副交感神经末末节同源。ENS 的另一个主要输入来自节后交感神经元。因此，ENS 可以被认为是“神经节后”或“终末器官”，而对于交感神经分支，可以认为是“神经节后”。来自交感神经和副交感神经部门的输入都调节了 ENS 的活动，但 ENS 基本上可以在没有外源输入的情况下正常运作。离体 ENS 可以对局部刺激做出适当反应并控制肠道功能的大多数方面，包括启动蠕动活动以响应胃膨胀、控制分泌和吸收功能以及触发胆道收缩（框 14-1）。
2 自主神经系统的突触生理学
SYNAPTIC PHYSIOLOGY OF THE AUTONOMIC NERVOUS SYSTEM
2.1 交感神经和副交感神经分支对大多数内脏目标具有相反的作用
The sympathetic and parasympathetic divisions have opposite effects on most visceral targets
2.2 所有节前神经元（包括交感神经和副交感神经）都会释放乙酰胆碱并刺激节后神经元上的 N2 烟碱受体
All preganglionic neurons—both sympathetic and parasympathetic—release acetylcholine and stimulate N2 nicotinic receptors on postganglionic neurons
2.3 所有节后副交感神经元都释放 ACh 并刺激内脏靶标上的毒蕈碱受体
All postganglionic parasympathetic neurons release ACh and stimulate muscarinic receptors on visceral targets
2.4 大多数节后交感神经元将去甲肾上腺素释放到内脏靶标上
Most postganglionic sympathetic neurons release norepinephrine onto visceral targets
2.5 节后交感神经和副交感神经神经元通常具有毒蕈碱受体和烟碱受体
Postganglionic sympathetic and parasympathetic neurons often have muscarinic as well as nicotinic receptors
2.6 非经典发射机可以在 ANS 的每个级别释放
Nonclassic transmitters can be released at each level of the ANS
2.7 两种最不常见的非经典神经递质 ATP 和一氧化氮首先在 ANS 中被发现
Two of the most unusual nonclassic neurotransmitters, ATP and nitric oxide, were first identified in the ANS
3 内脏的中枢神经系统控制
CENTRAL NERVOUS SYSTEM CONTROL OF THE VISCERA
3.1 交感神经输出可以是大量和非特异性的，如战斗或逃跑反应，或对特定靶器官有选择性
Sympathetic output can be massive and nonspecific, as in the fight-or-flight response, or selective for specific target organs
3.2 副交感神经元参与许多简单的不自主反射
Parasympathetic neurons participate in many simple involuntary reflexes
3.3 各种脑干核提供对 ANS 的基本控制
A variety of brainstem nuclei provide basic control of the ANS
3.4 前脑可以调节自主神经输出，反过来，整合在脑干中的本能感觉输入可以影响甚至压倒前脑
The forebrain can modulate autonomic output, and reciprocally, visceral sensory input integrated in the brainstem can influence or even overwhelm the forebrain
3.5 CNS 控制中心监督本能反馈回路并协调前馈响应以满足预期需求
CNS control centers oversee visceral feedback loops and orchestrate a feed-forward response to meet anticipated needs
3.6 ANS 具有多级反射环
The ANS has multiple levels of reflex loops
4 Reference
- Smith et al. Insights into inner ear function and disease through novel visualizatio of the ductus reuniens, a semila communication between hearing and balance mechanisms. JARO (2022)
- http://www.cochlea.eu/en/cochlea
- http://www.cochlea.eu/en/cochlea/cochlear-fluids
