Observation of the petropharyngeal muscle in Japanese.

The petropharyngeal muscles were observed in 7 cadavers, 8 cases (1.4%) [both side: one case (0.3%), one side: 6 cases (1.9%)] in 614 Japanese cadavers. All cases of this supernumerary muscles of the stylopharyngeal muscle took origin from the petrous part of the temporal bone to inserted to the outer surface of the middle constrictor pharyngeal muscles. And also of its muscle bundles were innervated by the glossopharyngeal nerve and supplied from the ascending pharyngeal artery. The appearance of the sex differences male was much higher than female in Japanese.     

Anatomic and topographical characteristics of the correlations between glossopharyngeal nerve and autonomic nervous system in Canidae and Mustelidae

Using macro-microanatomical approach, the study of glossopharyngeal nerve was performed on carcasses of fur animals belonging to Canidae and Mustelidae families (mink, sable, sable polar fox, fox). The species peculiarities of interconnections of tympanic nerve with inner carotid nerve and ear branch of vagus nerve were established. The characteristics of the course and connection of the carotid sinus branch of glossopharyngeal nerve with sympathetic branches of cranial cervical ganglion, were defined. The variants of total absence of vagal pharyngeal branch with significant development of similar branch of glossopharyngeal nerve, were noted.     

An anatomical study of the levator veli palatini and superior constrictor with special reference to their nerve supply

We dissected 50 head halves of 25 Japanese cadavers (10 males, 15 females) to investigate the innervations of the levator veli palatini (LVP) and superior constrictor pharyngis. The branches supplying the LVP were classified into the following three types according to their origins: supplying branches that originated from the pharyngeal branch of the glossopharyngeal nerve (type I, four sides, 8%), branches that originated from a communicating branch between the pharyngeal branches of the glossopharyngeal and vagus nerves (type II, 36 sides, 72%), and those that originated from the pharyngeal branch of the vagus nerve (type III, 10 sides, 20%). In previous studies, supplying branches of type I were seldom described. Regarding the innervation of the superior constrictor, some variations were observed, and we consider it likely that there is a close relationship between these variations and the type of innervation of the LVP.     

Surgical anatomy of the platysma motor branch as a donor for transfer in brachial plexus repair

Object  Nerve transfers have become a major weapon in the battle against brachial plexus lesions. Recently, a case involving the successful use of the platysma motor branch to re-innervate the pectoralis major muscle was reported. The present anatomical study was conducted to clarify the surgical anatomy of the platysma motor nerve, in view of its potential use as a donor for transfer. Methods  Microsurgical dissections of the facial nerve and its terminal branches were performed bilaterally in five formaldehyde-fixed cadavers, thereby yielding ten samples for study. The relationships between the platysma motor branch and adjacent structures were studied and measurements performed. Specimens were removed and histologically studied. Results  The platysma branch of the facial nerve was found to arise from the cervicofacial trunk. In five instances, one main nerve innervated the platysma muscle, and there was a smaller accessory nerve; in four cases, there was just a single branch to the muscle; and in one case, there was a main branch and two accessory branches. The distance between the gonion and the platysma motor branch averaged 0.8 cm (range 0.4–1.1 cm). The platysma branch received thin anastomotic rami from the transverse superficial cervical plexus. The neural surface of the platysma motor branch, on average, was 76% the surface area of the medial pectoral nerve. Conclusion  The anatomy of the platysma motor branch is predictable. Contraction of the platysma muscle is under voluntary control, which is an important quality for a donor nerve selected for transfer. The clinical usefulness of platysma motor branch transfer still must be elucidated.     

On a complex anastomosis of the glossopharyngeal nerve in humans

The glossopharyngeal nerve shows anastomoses with the facial nerve and the sympathetic nervous system. One anastomosis extends from the interconnected stylopharyngeal branches, immediately after having perforated the muscle towards the base of skull. Cranially, varying targets of the ascending nerve can be discriminated: 1) The temporal bone. 2) The facial nerve. 3) The sympathetic nerve plexus of the internal carotid nerve. This complex anastomosis was now studied under the dissecting microscope in more detail. The investigation revealed a more complicated distribution pattern of the anastomotic nerve than previously assumed, i.e. the existence of a solitary ascending branch could only be proved in a minority of cases (seven of twenty individuals). In the majority, a delicate nerve plexus could be visualized (thirteen of twenty individuals). In the cases of an anastomosis with the facial nerve, the stylohyoid branch was observed to be the main target of the ascending nerve. Also, connections with the internal carotid nerve were seen. In addition, delicate endings of the branches were demonstrated ramifying in the styloid process or penetrating the temporal bone at other sites. The histological demonstration of ganglion cells within the ascending nerve or nerve plexus suggests parasympathetic and sensoric functions for this anastomosis.     

Nucleus ambiguus of the rabbit: Cytoarchitectural subdivision and myotopical and neurotopic representations

The cytoarchitectural subdivisions of the nucleus ambiguus of the rabbit and its myotopical and neurotopical representations were investigated with HRP labeling. The nucleus was subdivided into the compact cell group (CoG), the medial and lateral scattered cell groups (SGm and SGl), and the diffuse cell group (DiG). The CoG was formed by esophageal, pharyngeal constrictor, and palatal motoneurons in the rostral half of the nucleus. The SGm and SGl were located medial and lateral to the CoG, respectively, in the rostral one-third of the nucleus. Stylopharyngeal and cricothyroid motoneurons were located in the most rostral one-fifth of the SGm and the remaining four-fifths, respectively, whereas the SGl was not labeled with HRP injections into the palatal, pharyngeal, esophageal, and laryngeal muscles. The DiG was formed by recurrent laryngeal motoneurons in the caudal two-thirds of the nucleus. Neurons of origin for the glossopharngeal nerve occupied the stylopharyngeal region, with a few of them scattered in the CoG and SGl. Neurons giving rise to axons in the superior laryngeal nerve occupied the cricothyroid region, with a few of them scattered in the pharyngeal constrictor region; whereas the pharyngeal vagal branch originated from the pharyngeal constrictor and palatal regions. Neurons of the DiG, SGl, and esophageal region contributed to the infranodosal vagus nerve; esophageal fibers of the recurrent laryngeal nerve originated from the dorsal esophageal region. Laryngeal fibers of the recurrent laryngeal nerve originated from the DiG, the caudal neurons of which had axons traversing the cranial accessory root. © 1993 Wiley-Liss, Inc.     

Innervation of human soft palate muscles

Our objective was to determine the branching and distribution of the motor nerves supplying the human soft palate muscles. Six adult specimens of the soft palate in continuity with the pharynx, larynx, and tongue were processed with Sihler's stain, a technique that can render large specimens transparent while counterstaining their nerves. The cranial nerves were identified and dissection followed their branches as they divided into smaller divisions toward their terminations in individual muscles. The results showed that both the glossopharyngeal (IX) and vagus (X) nerves have three distinct branches, superior, middle, and inferior. Only the middle branches of each nerve contributed to the pharyngeal plexus to which the facial nerve also contributed. The pharyngeal plexus was divided into two parts, a superior innervating the palatal and neighboring muscles and an inferior innervating pharyngeal constrictors. The superior branches of the IX and X nerves contributed innervation to the palatoglossus, whereas their middle branches innervated the palatopharyngeus. The palatoglossus and palatopharyngeus muscles appeared to be composed of at least two neuromuscular compartments. The lesser palatine nerve not only supplied the palatal mucosa and palatine glandular tissue but also innervated the musculus uvulae, palatopharyngeus, and levator veli palatine. The latter muscle also received its innervation from the superior branch of X nerve. The findings would be useful for better understanding the neural control of the soft palate and for developing novel neuromodulation therapies to treat certain upper airway disorders such as obstructive sleep apnea.     

Interrelationships between the innervations from the laryngeal nerves and the pharyngeal plexus to the inferior pharyngeal constrictor

Purpose

The inferior constrictor is innervated by the pharyngeal plexus and the external and recurrent laryngeal nerves. The communication between these nerves may influence the innervations. However, the relations of their anastomoses with the innervations have been unclear. This gross anatomical study re-examined the configuration of the inferior constrictor and investigated the variations of the anastomoses and the innervations of the constrictor to clarify their interrelationships.

Methods

The inferior constrictor and the branches of the superior and recurrent laryngeal nerves and the pharyngeal plexus were examined under a binocular microscope in 30 Japanese cadavers.

Results

The inferior constrictor consisted of the oblique fibers from the thyroid and cricoid cartilages and the horizontal ones from the cricoid. The oblique fibers were innervated by the pharyngeal plexus from the dorsal and ventral surfaces. The external laryngeal nerve gave twigs to the oblique fibers and the cricothyroid from the lateral surface. The recurrent laryngeal nerve supplied the horizontal fibers from the ventral surface. The internal laryngeal nerve sometimes and the main trunk of the superior laryngeal nerve rarely supplied the upper oblique fibers. The communicating branches between the laryngeal nerves and the pharyngeal plexus sometimes gave twigs to the constrictor from the dorsal surface.

Conclusions

The innervations to the inferior constrictor from the laryngeal nerves and the pharyngeal plexus are classified into some types based on their branching patterns and anastomoses, suggesting that the dysfunctions of the laryngopharyngeal region vary according to the positional relationships between the affected part and the innervations types.     

Main trajectories of nerves that traverse and surround the tympanic cavity in the rat

To guide surgery of nerves that traverse and surround the tympanic cavity in the rat, anatomical illustrations are required that are topographically correct. In this study, maps of this area are presented, extending from the superior cervical ganglion to the otic ganglion. They were derived from observations that were made during dissections using a ventral approach. Major blood vessels, bones, transected muscles of the tongue and neck and supra and infrahyoid muscles serve as landmarks in the illustrations. The course of the mandibular, facial, glossopharyngeal, vagus, accessory and hypoglossal nerves with their branches, and components of the sympathetic system, are shown and discussed with reference to data available in the literature. Discrepancies in this literature can be clarified and new data are presented on the trajectories of several nerves. The course of the tympanic nerve was established. This nerve originates from the glossopharyngeal nerve, enters the tympanic cavity, crosses the promontory, passes the tensor tympani muscle dorsally, and continues its route intracranially to the otic ganglion as the lesser petrosal nerve after intersecting with the greater petrosal nerve. Auricular branches of the glossopharyngeal and of the vagus nerve were noted. We also observed a pterygopalatine branch of the internal carotid nerve, that penetrates the tympanic cavity and courses across the promontory.     

A variation of the brachial plexus characterized by the absence of the musculocutaneous nerve a case report

A variation of the brachial plexus characterized by the absence of the musculocutaneous nerve on both sides was observed during the dissection of a 72 year-old female cadaver. The long thoracic nerve included only the fibers from C5 and C6 on the left side. The musculocutaneous nerve was absent and two branches from the lateral cord innervated the coracobrachialis muscle. The median nerve innervated the biceps brachii and brachialis muscles in the arm and also gave off the lateral antebrachial cutaneous nerve. Additionally, a communicating branch was found from the median nerve to the ulnar nerve in the forearm. The knowledge of the anatomical variations of the peripheral nerve system can help give explanation when encountering an incomprehensible clinical sign.     

The Carotid Sinus Nerve—Structure,Function, and Clinical Implications

Interest has been renewed in the anatomy and physiology of the carotid sinus nerve (CSN) and its targets (carotid sinus and carotid body, CB), due to recent proposals of surgical procedures for a series of common pathologies, such as carotid sinus syndrome, hypertension, heart failure, and insulin resistance. The CSN originates from the glossopharyngeal nerve soon after its appearance from the jugular foramen. It shows frequent communications with the sympathetic trunk (usually at the level of the superior cervical ganglion) and the vagal nerve (main trunk, pharyngeal branches, or superior laryngeal nerve). It courses on the anterior aspect of the internal carotid artery to reach the carotid sinus, CB, and/or intercarotid plexus. In the carotid sinus, type I (dynamic) carotid baroreceptors have larger myelinated A-fibers; type II (tonic) baroreceptors show smaller A- and unmyelinated C-fibers. In the CB, afferent fibers are mainly stimulated by acetylcholine and ATP, released by type I cells. The neurons are located in the petrosal ganglion, and centripetal fibers project on to the solitary tract nucleus: chemosensory inputs to the commissural subnucleus, and baroreceptor inputs to the commissural, medial, dorsomedial, and dorsolateral subnuclei. The baroreceptor component of the CSN elicits sympatho-inhibition and the chemoreceptor component stimulates sympatho-activation. Thus, in refractory hypertension and heart failure (characterized by increased sympathetic activity), baroreceptor electrical stimulation, and CB removal have been proposed. Instead, denervation of the carotid sinus has been proposed for the “carotid sinus syndrome.” Anat Rec, 302:575–587, 2019. © 2018 Wiley Periodicals, Inc.     

内镜辅助下经口径路咽旁间隙的解剖

目的 探讨内镜辅助下经口径路咽旁间隙的解剖结构,了解该径路重要的解剖标志及颈内动脉、颈内静脉及后组颅神经等解剖结构的毗邻关系,为内镜辅助下经口径路切除咽旁间隙肿瘤提供解剖学依据。方法 在内镜辅助下对新鲜尸头标本5例(共10侧)行经口径路咽旁间隙解剖。结果 茎突前间隙以咽上缩肌及翼内肌作为解剖标志,茎突咽肌、茎突舌肌是茎突前间隙的后界也是进入茎突后间隙的标志,重要的血管及后组颅神经（舌咽神经、迷走神经、副神经、舌下神经）位于茎突后间隙。以茎突尖端为标志测量距舌咽神经、舌下神经及迷走神经的水平距离分别为（3.05±0.08）mm（2.94～3.14 mm）、(2.94±0.04）mm（2.44～2.56 mm）、（1.50±0.03）mm（1.46～1.56 mm）;以茎突咽肌为标志进行测量,距舌下神经及迷走神经的水平距离分别为;（3.00±0.03）mm（2.96～3.04 mm）、（5.99±0.03）mm（5.94～6.04 mm）,而舌咽神经基本紧贴该肌内侧面。副神经的走行距离茎突及茎突咽肌较远,经口手术径路几乎不会碰到。结论 内镜辅助下经口径路可较好的暴露咽旁间隙结构,咽上缩肌、翼内肌、茎突咽肌、茎突舌肌是重要的解剖标志。     

The communicating branch of the 4th cervical nerve to the brachial plexus: the double constitution, anterior and posterior, of its fibers

Twenty-four adult cadavers (48 sides) were used to investigate the incidence of a branch arising from the ventral ramus of the fourth cervical nerve (C4) with the phrenic nerve and subsequently joining the brachial plexus. Six brachial plexuses with spinal cords and phrenic nerves were dissected under a surgical microscope to investigate localization of fibers contained in the C4 branch to the brachial plexus. The incidence of the C4 branch was 23% (11/48 sides). Branches from C4 to the brachial plexus divided into anterior and posterior divisions on four sides (4/6 sides). On two sides, the branch did not divide but consisted entirely of an anterior division (2/6 sides). In the brachial plexus, anterior division fibers of the C4 branch were intertwined with fibers from the anterior divisions of the ventral rami of the fifth and sixth cervical nerves. They then passed to the suprascapular nerve and the anterior division of the superior trunk (6/6 sides). On the other hand, posterior division fibers of the C4 branch were intertwined with fibers from the posterior divisions of the ventral rami of the fifth and sixth cervical nerves. They then passed to the suprascapular nerve (2/6 sides) and the posterior division of the superior trunk (4/6 sides). The anterior division of the C4 branch received fibers from the ventral rootlets of the entire fourth cervical segment, whereas the posterior division received fibers from the ventral rootlets of the caudal half of the fourth cervical segment only. The fact that the suprascapular nerve received fibers from both the anterior and posterior divisions of the C4 branch was considered to support our claim that the human suprascapular nerve belongs to both the anterior and posterior divisions of the brachial plexus.     

Intracranial distribution of the sympathetic system in mice: DiI tracing and immunocytochemical labeling

The intracranial distribution of the cephalic branches of the superior cervical ganglion (scg) was studied in mice using indocarbocyanine dye (DiI) anterograde tracing. Two main branches were traced from the scg. The first branch joined the nerve of the pterygoid canal (the vidian nerve), npc, from which several intracranial sympathetic branches passed to the branches of the trigeminal nerve (tgn), abducent nerve (abn), trochlear nerve (trn), and oculomotor nerve (ocn). Most of the second branch joined the abn, from which sympathetic fibers dispersed in the distal region of the trigeminal ganglion (tgg) to form a plexus close to the ganglion's branches. Branches from this plexus joined the branches of the tgn, trn, and ocn. Several minor branches arising from the second branch of the scg were also observed. One formed a sympathetic plexus around the internal carotid artery (ica); a second formed a sympathetic plexus in the proximal region of tgg, close to its root; and a third branch coursed laterally to reach the ear by passing along the greater petrosal nerve (gpn). All of the intracranial trajectories traced from scg were found to be catecholaminergic, and likely sympathetic, using tyrosine hydroxylase (TH) immunocytochemistry.     

Development of the spinal nerves in the mouse with special reference to innervation of the axial musculature

Development of the mouse spinal nerves was studied. On E11 (11th day of gestation), the primitive spinal nerve fascicle extended ventrally in the anterior half of the sclerotome. Spinal nerves in the forelimb region united with each other to form the primitive brachial plexus. Their terminal segment was covered by a peculiar cell mass. On E12, five primary branches developed along the primitive spinal nerve trunk. The ramus dorsalis was originally a cutaneous nerve, supplying two series of branches to the skin of the back. The medial series was derived from the dorsal ramus of C2–C8, and the lateral series from C8 and the more caudal dorsal rami. Nerves of the former series took the presegmental course through the intermyotomic space, while those of the latter the postsegmental course. The ramus cutaneus lateralis was a nerve that took the presegmental course to become cutaneous. The ramus intercostalis externus was a muscle branch whose distribution was restricted within the segment. The ramus anterior was a muscle branch from the end of the primitive spinal nerve trunk. The ramus visceralis connected a thoracic nerve with the para-aortic sympathetic cell cord. On E13–16 the ramus anterior secondarily gave off a cutaneous branch (ramus cutaneus anterior). The ramus intercostalis externus extended ventrally deep to the intercostalis externus muscle, crossing just caudal to the ramus cutaneus lateralis that secondarily gave off branches to the obliquus externus abdominis muscle.     

尺神经中第七颈神经成份的行径及临床意义

用神经束追踪分离法解剖观察100侧成人第七颈神经分布至尺神经内的纤维行径。结合临床观察认为,尺神经内部有来自颈七的纤维,主要经4个交通部位加入到尺神经分布区内。证明脊神经相应节段与骨骼肌或肌群的支配关系是恒定的,只是由于在胚胎发生上臂丛组合的不同,使脊神经的分支到所支配的骨骼肌间的行径出现差异。上述研究结果,对臂丛中、下干损伤准确定位诊断有重要意义。     

Branching pattern of the external branch of the superior laryngeal nerve and its clinical importance

The external branch of the superior laryngeal nerve gives off many branches above the upper pole of the thyroid gland. Differentiating the branch innervating the cricothyroid muscle from the others may be important during surgery. Therefore, we aimed to demonstrate the branching pattern of this nerve in detail. In 34 human cadavers (59 sides), branches of the nerve were exposed and measurements related to them and neighboring structures were made. A cricothyroidal branch was present on all sides. This branch pierced the inferior pharyngeal constrictor muscle 3.9-17.6 mm above, 3.1-9.9 mm below, or at the level of the upper pole of the thyroid gland. On all sides, the nerve provided one or two thyroidal branches. The thyroidal branch was generally thinner than the cricothyroidal branch. But they were equal in size on three (5%) sides. The external laryngeal nerve provided two or three pharyngeal branches on all sides. These branches arose from the nerve 3.5-12.7 mm from the upper pole of the thyroid gland. Although the branch was generally thinner than the cricothyroidal branch, both branches were equal on four (6.7%) sides. Two cardiac branches were observed on two (3.3%) left sides. In conclusion, the cricothyroidal branch was generally thicker than the other branches. But on seven (11.8%) sides, thyroidal or pharyngeal branches and the cricothyroidal branch were equal in size. These data may be important during surgery as the surgeon may confuse the cricothyroidal branch with other branches of the external laryngeal nerve.     

The naris muscles in tiger salamander. I. Potential functions and innervation as revealed by biocytin tracing

The naris constrictor muscle, along with naris dilator and naris accessory muscles, controls the opening and closing of the external naris in tiger salamanders. It has been hypothesized that contraction of the naris constrictor muscle also causes the external nasal gland to secrete its contents inside the lateral wall of the external naris opening. This location is just rostral to vomeronasal organ and thus secretion in this region may be important for access of odorous compounds to vomeronasal organ. Little is known about the innervation of the naris muscles. To elucidate the neural control of these muscles, their innervation was examined using retrograde tract tracing with biocytin. Following application of biocytin to the naris constrictor muscle, labeling was observed in a ventral axonal plexus of the palatine nerve and numerous neuronal cell bodies distributed along this peripheral nerve plexus and within the main portion of the palatine ganglion. If the naris accessory and/or dilator muscles were also exposed to the tracer, the lateral-most branch of the palatine nerve and its associated neural cell bodies were labeled. To confirm the functional innervation of the muscles by the palatine nerve, the nerve was cut and the contraction of the muscles was eliminated. These findings demonstrate that the muscles controlling the external naris are under the control of palatine ganglion neurons. We hypothesize that this innervation of the naris constrictor muscle controls both muscle contraction and glandular secretion that may facilitate access of chemosensory substances to the vomeronasal organ.     

颈阔肌及其皮区的应用解剖

在３０具灌注红色乳胶的成人尸体上,借助手术显微镜调查了６０例颈阔肌的肌纤维、血液供应和神经的分布。两侧颈阔肌侧缘的肌纤维多数相互交错,在下形成一倒置的“Ｖ”型。