Nerve Plexuses

NERVE PLEXUSES, s. plexus nervorum, complex connections between nerve fibers. Plexuses are divided into internal and external. Internal plexuses exist in both the central nervous system and in peripheral nerves. In the central nervous system, plexuses are found, first, in the protoplasm of the nerve cell itself, where they are known under the name of Golgi networks; they lie either around the nucleus, or at the periphery of the cell, or even around it (see Nerve cells); second, in the gray matter at the place of fiber endings; these plexuses are especially clear in the cerebral cortex. Horizontal fibers of the cortex, running parallel to the surface, in places gather into denser plexuses, known under the name of tangential strips—outer and inner strips of Baillarger, association strip of Meynert. Between these strips lie looser plexuses; Edinger distinguishes plexus interradialis, lying between the bundles of radial fibers, and plexus supraradialis, lying above these fibers; in the latter, a strip is formed from thicker fibers, known under the name of Kaes's strip; the layer of cortex where plexus supraradialis is located is called stratum plexiforme. In the bulbus olfactorius there are two stratum plexiforme—str. molecular, s. str. plexiforme externum and str. plexiforme internum or the layer of collaterals. In the bulbus olfactorius there is a very dense plexus in the glomeruli olfactorii. Cells with short axons form in the cortical layers plexuses around the pyramidal cells, known under the name of "baskets"; such plexuses, "baskets", also exist in the cerebellum around Purkinje cells. And finally, third, plexuses exist between individual bundles. Nerve fibers, leaving the nerve cells, connect into bundles both in the central nervous system and in peripheral nerves, but in the bundles the nerves do not maintain either a direct direction or their original arrangement—they divide, connect with other nerve fibers, leave one bundle to pass into another. External plexuses form in the area of the peripheral nervous system between the trunks and branches of both the cerebrospinal and autonomic systems. External plexuses can be of three kinds—plexuses of roots, trunks, and terminal plexuses. Root plexuses are formed due to numerous connections of roots, most often anterior (plexuses brachial, cervical, lumbosacral), but sometimes posterior. Plexuses between trunks are encountered along the course of nerves up to their terminal branches. An example can be the plexuses of the n. facialis and n. vagi. The most widespread are the terminal plexuses, which occur in various tissues and organs; these external plexuses are especially widespread in the autonomic nervous system. The physiological significance of nerve plexuses—the substitutive function of some nerves in case of their disease by others and the diversity of peripheral innervation. Phylogenesis. The formation of nerve plexuses is observed in the animal kingdom at very low levels of development in individuals in which the nervous system is not yet differentiated and the entire nervous apparatus consists exclusively of plexuses. Pathology of nerve plexuses—see separate plexuses: Brachial plexus, Lumbosacral, Cervical, Autonomic nervous system, Vagus nerve, Autonomic neuroses and various internal organs. In the table below (pp. 359-370) only external nerve plexuses are given. \p 369

NERVE PLEXUSES

360 Table of nerve plexuses. Name of the plexus and character From what it originates or what it forms Location With what it anastomoses and where it ends Aorticus abdominalis Vasomotor Originates from plexus coeliacus, is supplemented by branches from lumbar nodes of the sympathetic trunk. Nodes are located in the plexus Lies on the aorta in the form of two bundles connected by transverse fibers Ends in the wall of the aorta, sends fibers to gangl. and plexus mesentericus inf., to colon descendens, to colon sigmoideum and to rectum Aorticus thoracalis Vasomotor Arises from the peripheral part of plexus cardiaci, is supplemented by branches from thoracic nodes of the sympathetic trunk and from n. splanchnicus major See Plexus aorticus abdominalis Ends in the wall of the aorta. Through hiatus aorticus fibers from it pass into the abdominal cavity and connect with plexus coeliacus Arteriae cerebri ant. Vasomotor Formed by fibers from plexus cavernosus Lies in the wall of a. cerebri ant., continues on its branches Ends in the walls of the vessels Arteriae cerebri mediae Vasomotor By fibers from plexus cavernosus Lies in the wall of a. cerebri mediae and continues on its branches Ends in the walls of the vessels Arteriae cerebri post. Vasomotor By fibers from plexus basilaris Lies in the wall of a. cerebri post., continues on its branches Ends in the walls of the vessels Arteriae ovaricae Vasomotor and secretory By branches from plexus coeliacus Surrounds a. ovarica Ends together with the artery in ovariumu in fundus uteri 7 8 Arteriae choroideae Vasomotor and secretory By fibers branching from plexus cavernosus Lies in the wall of a. chorioideae, continues on its branches Ends in the wall of a. chorioideae Auerbach's, s. myenteric Motor By fibers going from plexus mesentericus sup. (in detail, see Vegetative nervous system, nerves of the stomach, nerves of the intestine) Consists of longitudinal and transverse bundles, in the nodal points of which lie cells, from which fibers depart to form new plexuses. Placed between the longitudinal and circular muscles of the gastrointestinal tract Innervates the smooth muscles of the gastrointestinal tract Auricularis post. Vasomotor By anterior ascending branches from gangl. sympatheticum cervicale sup. through n. auriculi externi Lies in the wall of a. auricularis post. Ends in the wall of the artery Brachialis - see Brachial plexus Bronchialis Motor and vasomotor By branches of plexus cardiaci Surrounds the bronchial arteries Continues into plexus pulmonalis Cardiacus profundus Motor By cardiac branches from n. vagus, laryngeus super., laryngeus inf. and from three cervical nodes of the sympathetic trunk Covers the convex edge of arcus aortae and the place of division of a. pulmonalis; gangl. cardiacum (Wrisbergi) is located in this plexus End in the muscle of the heart. Give branches to plexus trachealis and bronchialis, for the aorta and a. pulmonalis, to the wall of the atrium and plexus coronarius / Cardiacus superficialis Motor Placed to the right and above the deep one, behind the aortic arch Caroticus communis Vasomotor Formed by n. carotici, going from gangl. cervicale medium et inferius Surrounds a. carotis communis Ends in the wall of a. carotis communis Caroticus externus Vasomotor Formed by n. carotici externi from gangl. cervicale superius; contains gangl. temporale Scarpa Accompanies a. carotis externa upward to its division Passes to the branches of a. carotis ext., forming plexuses around them Caroticus internus Motor and vasomotor Formed by n. caroticus internus from gangl. cervicale superius Accompanies a. carotis interna in canalis caroticus and in sinus cavernosus Besides the wall of the artery it goes into nn. oculomotorius, abducens жм Name of the plexus or plexus*.) and character From what it originates or what it forms Location With what it anastomoses and where it ends Cavernosus Vasomotor By medial and lateral branches from gangl. cervicale superius Lies in sinus cavernosus, surrounds the third bend of a. carotis interna In the wall of a. carotis interna Cavernosus clitoridis Vasomotor Nn. cavernosi clitoridis major et minores, originating from plexus vesico-vaginalis Accompanies a. clitoridis Ends in corpus cavernosus clitoridis Cavernosus penis Vasomotor From plexus hypogastricus inf., constitutes a continuation of plexus prostatici Accompanies pars membranacea urethrae, pierces m. transversus perinei profundus and lies on the dorsal surface of penis, where it connects with n. penis and n. pudend. Gives nn. cavernosi major et minores Ends in corpus cavernosus penis, sends branches to pars membranacea urethrae Cervicalis, syn. cervical plexus - see Cervical plexus Cervicalis post. - see Cervical plexus Cervico-brachialis - see Brachial and cervical plexuses Coccygeus, syn. coccygeal plexus - see Lumbosacral plexus Coccygeal - see Lumbosacral plexus Coeliacus, s. plexus Solaris, s. cerebrum abdominale, syn. solar plexus Motor, secretory, vasomotor The basis of p. coeliacus is a paired semilunar node - gangl. coeliacum, s. gangl. solare: the most important roots - nn. splanchnici, abdominal branches of n. vagi, branches from the last thoracic and two upper lumbar nodes Placed on the initial part of aortae abdominalis, surrounds the beginning of a. coeliaca and a. mesentericae sup., extends laterally to the adrenal glands, upward to hiatus aorticus, downward to a. renalis; behind it are the medial crus of the diaphragm. Upward it connects with plex. aorticus thoracalis, downward it continues into plex. aort. abdominalis Ends in internal organs through the means of secondary plexuses originating from it: plexus phrenicus, suprarenalis, renalis, spermaticus, gastricus sup., hepaticus, lienalis, mesentericus sup. Coronarius cordis ant. Motor Formed by branches originating from plexus cardiacus profundus et superfic. In the plexuses a mass of microscopic nodes is embedded Surrounds the root of the aorta and a. coronaria dext Numerous branches to the right ventricle and to the right atrium 2? Coronarius cordis post. Vasomotor Surrounds the root of a. coronaria sinistra Ascending branches to the left atrium and descending to the left ventricle Deferentialis Vasomotor Formed by branches from plexus hypogastricus; ganglion cells are located in the plexus Surrounds the ampulla of ductus deferens and its upper part In the walls of the vessels of ductus deferentis Dentalis inf. Sensory and vasomotor Formed by nn. alveolares of n. mandibularis In canalis mandibulae From it depart rami dentales inf. to the teeth of the lower jaw and rami gingivales inf. to the gums of the lower jaw Dentalis sup. Sensory and vasomotor Formed by rami dentales et rami alveolares sup. post. et medius Located partly in the bony substance of the upper jaw, partly under the mucous membrane of the upper jaw cavity From it depart rami dentales sup. to the teeth of the upper jaw and rami gingivales sup. to the gums of the upper jaw Epicardiacus Sensory and vasomotor Formed by branches from plexus cardiacus profundus et superfic. Located under the epithelium of the epicardium Ends freely under the epithelial cells of the epicardium Femoralis Vasomotor Is a continuation of plexus iliaci Surrounds a. femoralis Ends in its wall Frankenhauser's Motor and vasomotor From plexus hypogastricus, contains many small nodes In the form of a dense plexus lies on the lateral surface of the uterus Ends in the muscles of the uterus and vagina, as well as surrounds the vessels *з Name of the plexus or plexus'a and character From what it originates or what it forms Location With what it anastomoses and where it ends Gastricus ant. Motor, vasomotor and secretory Gastricus inf. Motor, vasomotor and secretory Gastricus post. Motor, vasomotor and secretory Gastricus sup. Motor, vasomotor and secretory Haemorrhoidalis medius Motor and vasomotor Haemorrhoidalis sup. Motor and vasomotor Hepaticus Vasomotor and secretory Hypogastrici inferiores Vasomotor and motor Hypogastricus sup Vasomotor and motor Iliacus Vasomotor Infraorbitalis (Rau-ber) Sensory, motor Formed by rami gastrici of n. vagus sinistri and n. sympathici Formed by branches of plex. hepatici Formed by rami gastrici of n. vagus dextri and n. sympathici Formed by branches from plexus coeliacus; contains separate microscopic nodes Formed by branches of plexus hypogastricus inf. Formed by branches from plexus mesentericus inf. Located on the anterior surface of the stomach Located along a. gastro-duodenalis and reaches the greater and lesser curvature of the stomach Located on the posterior side of the lesser curvature Unpaired, is composed of branches of n. vagus dextri and branches from plexus coeliacus.

The plexus contains nodes and individual cells of Parinae; they arise from the continuation of the plexus hypogastricus superior and receive branches from the sympathetic trunk and from the roots S5 and S1. It accompanies the a. gastrica sinistra, reaches the lesser curvature of the stomach. It surrounds the rectum. It surrounds the upper part of the rectum. Bundles of fibers in the form of a narrow-meshed network surround the a. hepatica and ductus choledochus, hepaticus and cysticus, reach the portal vein and participate in the formation of the plexus gastricus inferior. It ends in the wall of the stomach. It ends in the wall of the stomach. It ends in the wall of the stomach. It anastomoses with the plexus gastricus from the n. vagus and with the plexus hepaticus, ending in the wall of the stomach. It ends in the wall of the rectum. It ends in the wall of the rectum. It penetrates into the liver together with the a. hepatica. Unpaired, continuation of the plexus aortici abdominalis, it is strengthened by fibers from the lower lumbar node. By branches of the plexus aortici. By anastomoses of the facial branches of the n. facialis with the n. infraorbitalis and n. buccinatorius. In the form of two bundles, they are located on the vasa hypogastrica of the small pelvis and on the lateral surface of the rectum; on the floor of the small pelvis, the bundles spread in the form of an extensive plexus. It is located on the lower part of the aortae abdominalis and divides at the level of the promontorium into 2 branches - hypogastricae inferior. It surrounds the a. iliaca communis and a. iliaca externa. It continues on the a. femoralis and a. poplitea, forming the plexus femoralis and plexus popliteus. It is located on the face below the foramen infraorbitale. From the plexus arise branches for the pelvic viscera through secondary plexuses - haemorrhoidalis medius, vesicalis, deferentialis, seminalis, prostaticus, cavernosus penis or plexus utero-vaginalis and cavernosus clitoridis. It continues into the plexus hypogastricus inferior. It innervates the walls of the a. iliacae. It innervates the skin of the lower eyelid, nose and upper lip, the mucous membrane of the upper lip and the muscles of the face. Intestinalis - see Plexus mesentericus inferior and Plexus mesentericus superior. Lienalis. Vasomotor, motor, secretory. Lingualis. Vasomotor and secretory. By branches of the ganglion coeliacium sin. and n. vagus dext. Nn. carotici externi. It surrounds the a. lienalis and its branches. It surrounds the a. lingualis. It innervates the a. lienalis, spleen, greater curvature of the stomach and pancreas. It innervates the walls of the a. lingualis and glandula sublingualis. It anastomoses with the ramus lingualis n. glossopharyngei. Lumbosacralis - see Plexus lumbosacralis.

NERVE PLEXUSES

88v j Name of the plexus and character From where it originates or what it is formed from. Location With what it anastomoses and where it ends Mammarius interims Vasomotor By branches of gangl. cervicalis inf. On a. mammaria int. Innervates a. mammari int. Maxillaris externus Vasomotor and secretory Nn. carotici externi (from gangl. cervicalis sup.) Wraps around a. maxillaris ext. and its branches Innervates a. maxil. ext. and gland. submaxillaris. Sends anastomosis to gangl. submaxillare Maxillaris internus Vasomotor By ascending branches of plexus carotici ext. Wraps around a. maxillaris interna and its branches Innervates a. maxillaris int. and its branches and anastomoses with gangl. sphenopalatinum 1_____ Meningeus (ant. and post.) Sensory and vasomotor Rr. meningei of spinal nerves and branches of sympathetic nerve On the anterior and posterior walls of the vertebral canal Ends in the bones, ligaments and vessels of the spine and in the membranes of the spinal cord Meningeus n. sympathicus Vasomotor By branches of plexus carotici ext. Wraps around a. meningea media and accompanies it into the cranial cavity Innervates a. meningea media. Anastomoses with the II branch of n. trigemini via n. meningeus med. and with the III branch of n. trig. via n. spinosus and with gangl. oticum Mesentericus inf. Motor, vasomotor and secretory Formed from plexus aorticus abdominalis and gangl. mesentericum inf. Accompanies a. colica sinistra and a. haemorrhoidalis Innervates colon descenders, sigmoideum and the upper part of recti, forming plexus haemorrh. sup. (see above) Mesentericus sup. Motor By branches of plexus coeliacus Accompanies a. mesenterica sup. and its branches Gives rami pancreaticoduodenales to the head of pancreas and the lower part of duodenum, rami intestinales for jejunum and ileum, rami colici for caecum, colon ascendens and transversum. Ends in the musculature of the intestine and anastomoses with plexus myentericus and submucosus (see below) Meissneri - see Plexus submucosus D7 Myentericus - see Auerbach's plexus ^: Nervous piae matris (spinalis) Vasomotor By branches of n. sympathici and spinal nerves Located on the outer layer of the pia mater of the spinal cord Innervates the pia mater of the spinal cord Occipitalis Vasomotor By branches of plexus carotici Wraps around a. occipitalis Innervates a. occipitalis 60 61 62 Oesophagei ant. Motor Rami oesophagei n. vagi sinistri Located on the anterior surface of the esophagus 1 Innervate the musculature and mucous membrane of the lower half of the esophagus Oesophagei post. Motor Rami oesophagei n. vagi dextri Located on the posterior surface of the esophagus Ophthalmicus Vasomotor By branches of plexus cavernosi Accompanies a. ophthalmica Innervates a. ophthalmica, vessels of the orbit, and sends a branch to a. centralis retinae 63 64 Parotideus (n. facialis) Secretory and motor By branches of n. facialis, which, entering the parotid gland, divides into several branches, each of which again divides into two Located in the parotid gland Innervates the parotid gland and ends in the muscles of the face Pharyngeus Motor Formed by pharyngeal branches of the cervical part of the vagus nerve, pharyngeal branches of the glossopharyngeal nerve and branches of the sympathetic nerve Located on the outer surface of m. constrictor pharyngis med. Innervates the muscles and mucous membrane of the pharynx, forming two plexuses - in the circular musculature and in the submucous tissue - similar to plexus myentericus and plexus submucosus. Sends branches to m. levator veli palatini and to m. uvulae 3SS «ж Name of the plexus and character From where it originates or what it is formed from Location With what it anastomoses and where it ends Pharyngeus ascensens Vasomotor By ascending branches of gangl. cervicalis sup. Located on a. pharyngea ascendens Innervates a. pharyngea ascendens. Anastomoses with the previous plexus Phrenicus Vasomotor and motor By branches of n. splanchnici, plexus coeliacus and r. phrenico-abdominalis n. phrenici). The plexus is paired, the left one is more powerful, contains gangl. phrenicum Accompanies aa. phrenicae inf. Innervates aa. phrenicae inf. and the middle part of the diaphragm Popliteus - is a continuation of plexus iliaci (see above) Prostaticus Motor and secretory Is a continuation of plexus seminalis Located between the prostate gland and m. levator ani, in which several ganglia prostatica are located Innervates the prostate gland. Anastomoses with branches S2 and S3, among which are nn. erigentes penis; enters plexus cavernosus Pudendus - see Human nerves (pudendus plexus) Pulmonalis ant. and post. (syn. bronchialis ant. and post.) Vasomotor and motor Rami tracheales and rami bronchiales n. vagi and branches of the 4 upper thoracic nodes of the sympathetic nerve Located on the anterior and posterior surfaces of large bronchi, together with which they penetrate into the lungs. They contain a large number of microscopic ganglia Innervate bronchi, lungs and vessels of the lungs. Anastomose with plexus trachealis Renalis, see Vegetative nervous system By branches of plexus coeliacus, n. splanchnici minor (n. renalis post.) and branches of the lumbar part of the sympathetic trunk. The plexus contains ganglia renalia Accompanies a. renalis and together with it enters the kidney Innervates the capsule of the kidney, a. renalis and kidney, gives a branch to the ureter Sacralis - see Lumbosacral plexus Sacralis post. Motor and sensory By posterior branches of sacral nerves and the first coccygeal nerve Located on the posterior surface of a. sacroiliacae and the proximal part of lig. sacrotuberosi Medial branches innervate m. multifidus and skin on the posterior surface of the sacrum and coccyx; lateral branches penetrate through m. glut. maximus and innervate skin of the posterior superior gluteal area (nn. clunium medii). Articular branches penetrate into articulatio sacroiliaca Seminalis Motor and secretory Is a secondary plexus of plexus hypogastrici and receives fibers from S2 - S4 Wraps around the seminal vesicles Innervates the seminal vesicles and anastomoses with plexus deferentialis and plexus prostaticus Solaris - see Plexus coeliacus Spermaticus Vasomotor and secretory By branches of plexus renalis, mesenterici sup. and aortici abdominalis Accompanies vasa spermatica interna Innervates the testicle, in women the ovary and the fundus of the uterus and reaches fimbria ovarica and the outer end of the Fallopian tube. Anastomoses with plexus uterinus Subclavius Vasomotor By branches of the middle and lower cervical sympathetic nodes Wraps around a. subclavia and accompanies its branches Innervates the walls of a. subclaviae and a. carotis communis Submucosus (Meissneri) Vasomotor and secretory (see Vegetative nervous system) By branches of sympathetic and vagus nerves (for details see Vegetative nervous system, intestine) Located in the submucous tissue of the intestine Innervates the vessels of the submucous membrane of the intestine, Brunner's glands, muscularis mucosae, mucous membrane of the intestine and Lieberkühn's glands. Ends in the villi №№ Name of the plexus and character From where it originates or what it is formed from Location With what it anastomoses and where it ends Suprarenalis Secretory By branches of n. splanchnici major, upper lumbar node, n. vagi and plexus phrenici Located on the posterior and medial surfaces of the adrenal gland and, penetrating through the cortical layer, forms a plexus at the border of the medullary layer, in which ganglia are located Innervates the adrenal gland Temporalis superfic. Vasomotor By branches of nn. carotici externi Located on a. temporalis superfic. Innervates a. temporalis superfic. Thyreoideus inf. Vasomotor, secretory and trophic By branches of plexus carotici and vagus nerve (via n. recurrens) Located on a. thyreoidea inf. Innervates the walls of a. thyreoideae inf. and the thyroid gland 82 83 Thyreoideus sup. Vasomotor, secretory and trophic By anterior branches of gangl. cervicalis sup. and branches of n. vagi (via n. laryngeus sup.) Located on a. thyreoidea sup. Innervates a. thyreoidea sup. and the thyroid gland Trachealis Motor By branches of nn. laryng. sup. and inf. n. vagi and branches of gangl. cervicale sup. and gangl. stellatum, as well as branches of intercostal nerves Located on the trachea Innervates the trachea, ends in the circular ligaments and paries membranaceus of the trachea 84 85 Tympanicus (Jacobsoni) Vasomotor Formed by connecting the Jacobson's anastomosis, connecting gangl. petrosum n. vagi with gangl. oticum, with r. communicans cum plexu tympanico n. facialis and with nn. carotico-tympanici sup. and inf. (plexus caroticus) Located on the inner wall of the tympanic cavity Innervates the mucous membrane of the tympanic cavity via ramuli tympanici and gives off r. tubae, which can be traced to the pharyngeal opening of the Eustachian tube Utero-vaginalis Motor and sensory Is part of plexus hypogastrici, receives spinal fibers from S2 and S4 Located on the upper part of the vagina and cervix uteri. Numerous nodes are described in it (for details see "

(Autonomic nervous system) Innervates the uterus and vagina. Anastomoses at the base of the uterus with the plexus spermaticus and gives branches to the ovary and to the tubes. Vertebral Vasomotor. By branches of the lower cervical sympathetic ganglion. It is directed together with the a. vertebralis to its cerebral branches. Ends in the walls of the a. vertebralis. Anastomoses with the spinal cervical nerves, which join it during its passage through the canalis vertebralis. Vesical Motor. Formed by branches of the plexus hypogastrici and plexus deferentio-prostatici (utero-vaginalis). Together with the vessels it is directed to the base and upper part of the bladder. Innervates the bladder with the nerves of the uterus, receives medullated nerves from S2 and S3. Above the entrance to the bladder it receives a branch from the pelvic plexus (plexus hypogastricus), directed to the ureter, and a branch from the first sacral ganglion of the sympathetic trunk