·410·PARTVI NERVOUSSYSTEMInferiorganglionGlossopharyngeal n.AccessorynSternocleidomastoidAccessory n.StylopharyngeusCarotid sinus br.Vagus n.superior laryngeal n.Intermal br.TrapeziusmExtermalbr.Cricothyroid m.Brachiocephalic trunkRecurrent laryngeal n.EsophagusCardiac plexusLeft principal bronchusPulmonary trunkEsophageal plexusThoracic aortaHeartAnterior vagal trunkPosterior vagal trunkLeft lobeof liverCeliac plexusAnterior gastric br.StomachFig. VI-5-36 The vagus nerveAnterior vagal trunkPosterior vagal trunkBranchoffundusofstomachCardiac br.Hepatic br.Celiac br.Branches of posteriorAnterior gastric br.wall of stomachBranchesofanteriorwallofstomachPosterior gastric br.Crow'footCrow'footPyloric antrumFig.VI-5-37The branches of vagus nerve to stomachChenYao（陈尧）ZengZhaoming（曾昭明）the visceral functions of the body is also called theSection 3 Autonomicvisceral nervous system(Fig. VI-5-38).This systemhelps control arterial pressure,gastrointestinalmotili-Nervous Systemty and secretion, urinary bladder emptying, sweating,The portion of the nervous system that controlsbody temperature, and many other activities, some of扫描全能王创建
Chapter 5 Peripheral Nervous System · 411 :EyeballLacrimal glandNuclei of hypothalamusSalivary glandParasympatheticcentersinthebrainstemVessels of heaTracheaLungHeartLiverStomachSuprarenal glandSympathetic centers in thePancreathoracolumbarsegmentsofspinal cordKidney~12TSmall intestinLarge intestineParasympathetic centersin the sacral segments ofspinal cordUrinary bladdenAIntermal genital organDAFig.VI-5-38 Diagram showing general arrangement ofvisceral efferent nervewhich are controlled almost entirely and some onlywhich is also called the autonomic nerve is activatedpartially by the visceral nervous system. The visceralmainly by centers situated in the spinal cord, brainnervous system is dividable into the visceral afferentstem,and hypothalamus.Then the signals are trans-nerve and the visceral efferent nerve according to themitted to the visceral effectors which are the smoothmuscle, cardiac muscle and glands of the body.Oftentypeofthefibers.Thecell bodiesoftheformerarelocated in the sensory ganglia of the cranial and spinalthe autonomic nervous system also operates by meansof visceral reflexes. That is, sensory signals enteringnerve like the somatic sensory fiber, terminate in theinteroceptorofviscera.Andthevisceral efferentfiberthe autonomic ganglia, spinal cord, brain stem or扫描全能王创建
·412·PARTVINERVOUSSYSTEMhypothalamus can elicit appropriate reflex responsesThe two divisions are known as the craniosacral orbackto the visceral organs to control their activities.parasympathetic part and the thoracolumbar or sym-pathetic part. The anatomical names represent theI . Visceral Efferent(Motor)sites of origin from the central nervous system.NervesSympathetic nervous systemLike the somatic motor nerve, the visceral efferentnerve transmits the signals of the motor central to theThe sympathetic nerve originate in the spinal cordeffectors.However,ithas obviousdifferencewiththebetween the segments of T, or Cg and L(or L,) andsomatic motor nerve in the structures andfunctions:pass from here into the sympathetic chain frstly andDifferent effectors The somatic motor nerve in-then to the tissues and organs that are stimulated bynervates theskeletal muscles and it can be controlledthe sympathetic nerves. The sympathetic nervous sys-voluntarily by consciousness, whereas the visceraltem consists oftwo sympathetic trunks which is com-efferent nerve innervates the involuntary effectorscar-posed of paravertebral ganglia and interganglionicdiac muscle, smooth muscleandglands.branches,prevertebral ganlia (the celiac and superior,Different number of the neurons The visceralinferior mesenteric ganglia etc.), and nervous fibersefferentnervepathwayconsistsoftwoneuronsfromextending from theganlia to the different internal orthe lowercenterto the effector.The bodies of thefirstgans (Fig. VI-5-38, 39) .neuron, called the preganglionic neuron, lie in thecentral nervous system and terminates in a ganglion(1) Sympathetic gangliawhere they synapse with the cell bodies of the secondneuron,postganglionic neuron.In contrast, only a sin-The sympathetic ganglion include the paraverte-gle neuron exists in the somatic motor pathway.bral and prevertebral ganglia.Different fibers Different fibers consist of the1) Paravertebral gangliaThe paravertebral gangliadifferent component and diameter of the fiber.Theare arranged symmetrically on both sides of the ver-somatic motor nerve contains one kind of fibers.Buttebral column(Fig. V5-39).These ganglia are joinedthe autonomic nervous system is composed of theby interganglionic branches to form two sympatheticsympathetic and parasympathetic fibers.Each fibertrunks that extend from the base of the skull base toinnervates most of theviscera.Many organs are sup-the coccyx and are divided into cervical, thoracic,plied by both fibers,the actions of the two fibers arelumbar, sacral and coccygeal portions. There are 19-usually (but not always)antagonistic on the organ.24 ganglia in each sympathetic trunk. The cervicalBesides,the somatic motorfibers are all thick myelin-portion contains the superior cervical ganglion, theated fibers, but the visceral efferent fibers are the thinmiddle cervical ganglion and inferior cervical gan-myelinated orunmyelinated fibers.glion.There are 11 or 12 thoracic, 4 or 5 lumbar andDifferent distribution of the postganglionic3 or 4 sacral ganglia on each trunk.In the sacral por-fibers The somatic motor nerves are distributed pe-tion, the two trunks gradually approach each otherripherally in the form of nerve trunk and form theand fuse at the coccyx in the unpaired coccygealcharacteristic neuromuscular joint.Nevertheless,theganglion.postganglionicfibersofthevisceralmotornervesfab-2) Prevertebral ganglia The prevertebral gangliaricate the nerve plexuses around the viscera or bloodsituated in front of thevertebral column (Fig.VI-5-39),vessels, so the transmitters released from the termi-and are irregular ganglionic masses surrounding thenators act on several adjacent cells by the diffusionvisceral branches of the abdominal aorta they includemethods.the celiac, aorticorenal, superior and inferior mesen-The autonomic nervous system can be dividedteric ganglia.into two divisions anatomically and physiologically.扫描全能王创建
Chapter 5 Peripheral Nervous System · 413Superior cervicalganglionCervical plexuMiddle cervical ganglionInferior cervical ganglionBrachial plexusThoracic ganglia ofsympathetic trunkinterganglionicbranchIntercostal n.Greater splanchnic n.Lessersplanchnicn.Celiac ganglionAorticorenalSuperior mesentericganglionganglionInferiormesentericganglionAbdominal aorticplexusSuperior hypogastricLumbar plexuplexusSacral plexusGanglion imparFig.V-5-39The ganglia of sympathetic trunk and prevertebral gangliawith the naked eye.(2) Preganglionic, postganglionic fi-After the spinal nerve leaves the spinal cord, thebers and communicating branchespreganglionic sympathetic fibers leave the spinalnerve and pass through the white ramus into one ofThe sympathetic trunk is connected to the spinalthe ganglia of the sympathetic trunk.Then the coursenerves by communicating branches(Fig. VI-5-40) .of thefibers canbe one ofthefollowing three:It canThe communicating branches are identified as thesynapse with postganglionic neurons in the Paraverte-gray and white branches. This distinction is basedbral ganglion that it enters. ② It can pass upwards orupon thefact that the preganglionic nervous fibers aredownwards for variable distances in the sympatheticmyelinated and form the white ramus, while the post-trunk and synapse with one of the other paravertebralganglionic nervous fibers are unmyelinated and formganglia of the chain. It can pass through the sym-the gray ramus. The distinction, however, is largelypathetic trunk to terminate in one of the prevertebralacademic, since it is not possible to tell them apartganglia.扫描全能王创建
·414:PARTVINERVOUSSYSTEMSpinal ganglionSkiWhitecommunicating brSpinal n.Somatosensoryn.福Gray communicating br.Somatomotorn.Sympathetic trunkSkeletal m.Viscerosensoryn.Visceromotor n.Ganglia of sympathetictrunArrectorSweat glandPostganglionic fiberVesselsPreganglionic fibersFig. VI-5-40 Diagram of the course of sympathetic nervesThe postganglionic fibers originate from theinferior thyroid artery.The inferior cervical ganglionparavertebral or prevertebral ganglia, then travel tois situated between the transverse process of the lasttheir destinations in three ways: @Pass back from thecervical vertebra and the neck of the first rib, behindsympathetictrunkinto thecorresponding spinal nervesthe beginning of the vertebral artery.It is frequentlythrough gray rami, they control the blood vessels,fused with the first thoracic ganglion to form the cer-sweat glands, and piloerector muscles of the hairs.vicothoracic ganglion or satellite ganglion.② Surround the adjacent arteries as a layer ofThe distribution of the postganglionic fibersnervous plexus to innervate thebranches of thosearising from three cervical ganglia are described asarteries.③Terminate in a certain organ directly.thefollowings: Connecting to eight cervical nervesand accompanyingthemtothebloodvessels,sweat(3) General distributions of the sym-glands and arrectores pilorum of head and the upperpathetic nerveslimb.② Surrounding the arteries, such as the subcla-vian artery, internal carotid artery, vertebral artery,1) Cervical portion ofthe sympathetic trunk (Fig. VI-and basilar artery, form the nervous plexuses, and5-41,42)The cervical portion of the sympatheticthen accompanies the arteries to the glands, bloodtrunks consist of three ganglia according to their po-vessels,arrectorespilorumof theheadand neck,andsitions:The superior,middle,and inferior ganglia.Itthe dilator pupillae.The laryngopharyngeal brancheslies behind the carotid sheath and in front of the trans-pass to the side of the pharynx, where they join withverse process of the cervical vertebrae. The superiorbranches from the glossopharyngeal, vagus nerve tocervical ganglion is the largest of the three and placedforin the pharyngeal plexus. @ The three cervical gan-opposite the second and third cervical vertebrae.glia give off the superior,middleand inferior cardiacThe middle cervical ganglion is the smallest of thenerve respectively, which descend into the thorax tothree cervical ganglia,and is occasionally wanting.form the cardiac plexus.It is placed opposite the transverse process of sixth2) Thoracic portion(Fig. VI-5-42)Thetho-cervical vertebra, usually in front of, or close to, theracic portion of the sympathetic trunks consist of a扫描全能王创建
Chapter 5 Peripheral Nervous System · 415 .tebral column, along the medial margin of the psoasseries of ganglia (10-12) located in front of the headmajor. Each of them consists usually of four lumbarof the ribs. The thoracic sympathetic trunk give offthe branches which run as the followings: Con-ganglia connected together by interganglionic branch-nect by the gray rami to the 12 thoracic nerves andes. Gray rami communicantes pass from all the gan-glia to the lumbar nerves. The first and second, andaccompany them to the blood vessels, sweat glandssometimes the third, lumbar nerves send white ramiand arrectores pilorum of the thoracic wall.②Manypostganglionic fibers arising from the upper 5 thorac-communicantes to the corresponding ganglia.ic sympathetic ganglia join the thoracic aortic plexusThe braches arising from the lumbar ganglia are:esophageal plexus, pulmonary plexus and cardiac The gray rami communicantes connect the fiveplexus.③The greater splanchnic nerve is formed bylumbar nerves and accompanythemdistributeto thethe preganglionic fibers which pass through the fiftheffectors.②Thelumbarsplanchnicnervesformedbyto the ninth or tenth thoracic ganglia, and descendsthepreganglionicfibers passing through the lumbarobliquely on the bodies of the vertebrae, after perfo-ganglia end in the prevertebral ganglia in the abdom-rating the crus of the diaphragm, it ends in the celiacinal aortic plexus(Fig. VI-5-42, 43) and inferior mes-enteric plexuses, then give off the postganglionic fi-ganglion. @ The lesser splanchnic nerve is formed byby the preganglionic fibers from the ninth and tenth, andbers to the blood vessels, sweat glands and arrectorespilorum of the lower limb, the digestive tract belowsometimes the eleventh thoracic ganglia, and piercesthe diaphragm with the preceding nerve, andthe left colic flexure and pelvic organs.4) Pelvic portionThe pelvic portion of eachjoins the aorticorenal ganglion. The postganglionicfibers arisingfromtheceliacganglion and theaorti-sympathetic trunk is situated in front of the sacrum,medial to the anterior sacral foramina.It consists ofcorenal gangliondistributeto theliver,spleen,kidneyand the digestive tract before the left colic curve.two or three small sacral ganglia and a ganglion impar.Maxillary nerveIts postganglionic fibers are as the followings:Maxillary plexus①Gray rami communicantes pass from the ganglia toPterygopalatinethe sacral and coccygeal nerves, and distribute to theVidian nerveganglionblood vessels sweatglands and arrectorespilorumofInternal carotid.plexusCarotidathe lower limb and perineum.② Some branches jointhe pelvic nerve and distribute to the pelvic organs.5) Segmental distribution of the sympatheticSuperiorcervical ganglionnervesThe sympathetic fibers from segment T,ofspinal cord generally pass up the sympathetic chainto the head, from segment T, into the neck, from T-sinto thethorax,from T-u,into the abdomen,and fromTi2, L-2 into the pelvis and legs. Special nature ofthe sympathetic nerve ends in the adrenal medullae,therethey end directly on modified neuronal cells thatMiddlecervical ganglionsecrete epinephrine and norepinephrine into the bloodstream2.Parasympathetic systemInferiorcervicalganglionThe parasympathetic system is the craniosacralportion of the autonomic nervous system. Its primarycenters situated in the brain stem and sacral parasym-Diagram of cervical sympatheticFig. VI-5-41pathetic nuclei, the parasympathetic fibers leave the,nervescentral nervous system through cranial nerves II, VI,3) Lumbar potionThe lumbar sympatheticIX, X and the second and fourth sacral nerves.trunks are situated in anterolateral to the lumbar ver-扫描全能王创建
·416·PARTVINERVOUSSYSTEMSuperior cervical ganglionPharyngealplexusMeddle cervical ganglionCervicothoracicganglionBronchial plexusCardiac plexusEsophageal plexusCoronaryplexusesGanglia ofsympathetic trurGreatersplanchnCeliac plexuscessersplanchnicrGastricplexusSuperiormesentericplexusLumbarplexusAorticplexusInferior mesenteric plexusHypogastric plexusSacral plexusPelvic plexusVesicalplexusFig. VI-5-42Therightsymatneconnection withthoracic abdominal, and pelvic plexuses扫描全能王创建
Chapter 5 Peripheral Nervous System · 417 .Posterior vagal tGreater splanchnicCeliac gangliaLesser splanchnic rLowest splanchnic nAorticorenal gangliaSuperiormesentericplexusRenal plexusLumbar ganglion ofAbdominal aortic plexussympathetictrunkInferiormesentericplexusLumbarsplanchnAbdominal aortcriorhypoplexusFig. VI-5-43The lumbar and pelvic portion of sympathetic trunkpreganglionic fibers join the greater petrosal nerve to(1) Cranial portion of the parasympa-synapse with the pterygopalatine ganglionic cells inthe pterygopalatinefossa, the postganglionic fibersthetic system(Fig.VI-5-38)supplies the lacrimal gland, the glands of mucosa ofnasal cavity, oral cavity and palatine.And the otherIt includes the visceral efferent fibers in the ocu-part of the preganglionic fibers passes through thelomotor, facial, glossopharyngeal and vagus nerves.chorda tympani to join the lingual nerve trigeminalThese nerves have been described in previous pagesnerve, then synapse with the cells in the submandiband the details will be repeated here only as far as theularganglion,and the postganglionic fibers distributesupply to the visceral efferent fibers.to the submandibular and hypoglossal glands.1) Parasympathetic preganglionic fibers of the3) Parasympathetic preganglionic fibers of theoculomotor nerveThey originate from the acces-glossopharyngeal nerve(Fig. VI-5-33)They arisesory nucleus of oculomotor nerve(Edinger Westphalfrom the inferior salivatory nucleus situated in thenucleus) and synapse with the ciliary ganglion cells(-medulla oblongata and pass through the tympanicFig. VI-3-3, VI-5-22).The postganglionic fibers pro-nerve to the tympanic plexus,then give off the lesserceed in the short ciliary nerves and supply the ciliarypetrosal nerve to synapse with the cells of otic gangli-muscles and the sphincter pupillae of the eye.on.The postganglionic fibers distribute to the parotid2) Parasympathetic preganlionic fibers of thegland.facial nerve (Fig. VI-5-33) They originate from4) Parasympathetic preganglionic fibers of thethe cells in the superior salivatory nucleus locatedvagus nerveThey arise from the cells in the dorsalin the pons and divide into two part. One part ofthe扫描全能王创建
·418·PARTVINERVOUSSYSTEMlieved that the blood vessels, sweat glands, arectoresnucleus of vagus located in the medulla oblongata,pilorum and medullary part of the suprarenal glandand pass in the vagus nerve to the ganglia locatedare supplied only by the sympathetic nerve.in or near the target organs(thoracic and most of the5)Different effects to a visceral organTheabdominal viscera, including the heart, bronchioles,viscera receives a dual autonomic supply. In mostesophagus,stomach,small intestine,and the thelargecases,thetwo setsofnerves function antagonisticallyintestine before the left colicflexure)and supplyeach other.However, in some cases, the action of thethem.two divisions may not be antagonistic.The sympa-thetic nerve manages the activity in preparation of(2) Sacral portion of the parasympa-the organism for "flight or fight". In action, it tendsthetic nerve (Fig.VI-5-38)to produce vasoconstriction of the skin and viscera,shifting more blood to the brain and skeletal muscles,The preganglionic fibers arise from the sacralincreasing the rate of the heart beating and respira-parasympathetic nucleus in the second to forth sacraltion, the wider opening of the pupil, the elevation ofsegments of the spinal cord and penetrate out the an-the blood pressure and the dilatation of the bronchi.terior sacral foramen with the sacral nerve, then theyWhile, the actions of parasympathetic nerve to theform the pelvic splanchnic nerves and join the pelvicabove mentioned organs are on the contrary.So,whenplexus to synapse with the parasympathetic ganglionthe body in silence or sleep, the parasympatheticcells in or near the pelvic organs.The postganglionicfibers supply the pelvic organs and the digestive tractsystem is in excitation and the sympathetic system inbeneath the left colicflexure.inhibition.The phenomena are helpful to recovery ofthe power and reservoir of the energy.(3) Main differences between the(4) Visceral nerve plexusessympathetic and parasympatheticsystemThe visceral nervous plexuses are aggregations ofthe sympathetic,parasympathetic and visceral sensory1) Different lower centers The lower sympa-nerves, and theyare situated in the thoracic,abdom-thetic centers are situated in the lateral horn of theinal, and pelvic cavities.From the plexuses branchesthoracolumbar segments of the spinal cord; thelowerare given to the thoracic, abdominal, and pelvic vis-parasympathetic centers are in the parasympatheticcera(Fig. VI-5-42, 43).nucleus in the brain stem and sacral parasympathetic1)Cardiac PlexusThe cardiac plexus is situat-nucleus of the second, third and fourth sacral seg-ed at the base of the heart, and formed by the cardiacmentsofthespinal cord.branches arise from the superior, middle, inferior cer-2)Different locations of the peripheral gangliavical ganglia, the upper thoracic ganglia(Ti-s) and theThe sympathetic ganglia lie in either sides(paraverte-vagus nerve. It can be divided into a superficial andbral ganglia) and in front of(prevertebral ganglia) thea deep parts, the superficial part lies beneath the archvertebral column.The parasympathetic ganglia areof the aorta, in front of the right pulmonary artery;situated in or near the walls of the innervated organs.and the deep part, situated between the bifurcation ofSo, the preganglionic fibers of the parasympatheticthe trachea and the aortic arch. A small ganglion, thenerve are longer than those of the sympathetic nerve,cardiac ganglion (ganglion of Wrisberg), is occasion-whereas the postganglionic fibers of the parasympa-ally found in cardiac plexus, it is a parasympatheticthetic nerve are shorter than those of the sympatheticganglion and synapse with thefibers arising from thenerve.3) Different ratio of the preganglionic to thevagus nerve.The branches of the cardiac plexus formthe atrial plexus, the left and right coronary plexus,postganglionic neurons-A sympathetic pregangli-and distribute to the cardiac muscle with the arteries.onicfiber synapses with many postganglionic neurons2) Pulmonary plexus The pulmonary plexusthan the parasympathetic nerve, its effect is morecan be divided into the anterior and posterior pulmo-widespread than that of the parasympathetic nerve.nary plexus, and the two situated in front and rear4) Different distributions The peripheral dis-of the pulmonary trunk respectively. It is continuestribution of the sympathetic nerve is much wider thanwith the cardiac plexus, and the small ganglion in itthat of the parasympathetic nerve. It is generally be-扫描全能王创建
Chapter 5 Peripheral Nervous System · 419 .tum and vagina in the female. They are formed on ei-is madeup with thepostganglionic neurons of thether side by a continuation of the superior hypogastricvagus nerve.The pulmonary plexus is formed by thebronchial braches of vagus nerve, the branches of theplexus, the preganglionic parasympathetic fibersfromT2s sympathetic ganglia and the cardiac plexus. Thethe S2-4 sacral nerves, and the filaments from the firstbranches of it distribute to the lung with the bronchitwo sacral ganglia. From these plexuses numerousand pulmonary vessels.branches accompany the branches of the internal iliac3)Celiac PlexusThe celiac plexus is the largestarterytofomrectal,spermatic,vesical,prostatic,andof the sympathetic plexuses and situated at the leveluterovaginal plexus and distributed to the viscera ofof the upper part of the first lumbar vertebra, sur-the pelvis.rounds the celiac artery and the root of the superiormesenteric artery. It composed of the celiac ganglion,II . Visceral Afferent(Senso-the uperior mesenteric ganglion and the aorticorenalry) Nervesganglion etc. The plexus and the ganglia receive thegreater and lesser splanchnic nerves of both sidesThe action of viscera are controlled by the sym-and somefilaments from the right vagus, and give offpathetic and parasympathetic nerves and sensorynumerous secondary plexuses along the neighboringnerve.The visceral sensory nerve conducts the im-arteries.The celiac ganglion is joined by the pregan-pulses from enteroceptors of theviscera to the centralglionic fibers of the greater splanchnic nerve. Thenervous system.Then the nervous center adjusts theaorticorenal ganglionreceives the lesser splanchnicvisceralactionbythevisceralmotornervedirectlyornerve andgives off thegreaterpart of the renal plex-bodyfluid indirectly.us. And the superior mesenteric plexus is a continua-The bodies of the visceral sensory neurons locat-tion of thelowerpartofthe celiacplexus,receivingaed in the cephalic and spinal ganglia, their peripheralbranch fromthe junctionoftheright vagusnerve withprocesses are the various diameter myelinated orthe plexus.The branches of the celiac plexus accom-unmyelinatedfibers.Sensoryfibers comefrom thepany the branches of the aorta to form the secondarythoracic, abdominal and pelvic viscera through theplexus: hepatic,splenic,pancreatic, superior and infe-sympathetic and pelvic splanchnic nerves to reachrior mesenteric plexus and then distribute the organsthe sympathetic trunk and end in the dorsal horn ofwiththehomonymousvessels.the spinal cord. Others are the peripheral processes4)Abdominal aortic plexusIt is situated uponof the inferior ganglia of glossopharyngeal and vagusthe two sides and in front ofthe aorta, between the or-nerveswhosecentral processesaccompany thesetwoigins of the superior and inferior mesenteric arteries.nerves to terminate in the solitary nucleus of the brainThe abdominal aortic plexus is the continuous partstem. In the low sensory center, the afferent visceralof the celiac plexus and formedby branches derivedfibers have three conductive pathway: synapse withfrom the celiac plexus and ganglia, and receives fila-the visceral efferent neurons toform theviscera-visceralmentsfrom someofthelumbarganglia(T,-).Fromreflex②synapsewiththesomatomotorneuronstofomthis plexus arise part of the spermatic, the inferiorthe viscera-somatic reflex; ③ conduct the impulse to themesenteric, and the hypogastric plexuses; it also dis-cortex through a complex pathwayto give birthto thetributes filaments to the inferior vena cava (Fig. VI-5-visceral sensory.42,43)The visceral afferent fibers have their own fea5) Hypogastric Plexus The hypogastric plexustures in morphology and physiology,which are differ-is consist of the superior hypogastric plexus and theent from those of the somatosensory ones.pelvic plexus. And the superior hypogastric plexusis the continuous part of the abdominal aortic plexHigher pain thresholdus and situated in front of the last lumbar vertebraand the promontory of the sacrum,between the twocommon iliac arteries. It is formed by the union ofContrast to the somatosensory fibers, the num-thefilaments descend on either side from the lumbarber of the visceral sensory fibers is less, and mostsplanchnic nerve.The pelvic plexuses supply the vis-of these fibers is the thinner fiber and have a highercera ofthe pelvic cavity,and are situated at the sidespain threshold,so common intensive stimuli can notof the rectum in the male, and at the sides of the rec-扫描全能王创建