Microsurgical anatomy of the ocular motor nerves

This study was designed to provide anatomic data to help surgeons avoid damage to the ocular motor nerves during intraorbital operations. The microsurgical anatomy of the ocular motor nerves was studied in 50 adult cadaveric heads (100 orbits). Dissections were performed with a microscope. The nerves were exposed and the neural and muscular relationships of each portion of the nerve were examined and measured. The superior division of the oculomotor nerve coursed between the optic nerve and the superior rectus muscle after it left the annular tendon, and its branches entered into the superior rectus muscle and levator muscle. A mean of five fibers (range 3–7) innervated the superior rectus muscle, and a mean of one fiber (range 1–2) followed a medial direction (84%) or went straight through the superior rectus muscle (16%). The inferior division of the oculomotor nerve branched into the medial rectus, inferior rectus and inferior oblique muscles. The trochlear nerve ended on the orbital side of the posterior one-third of the superior oblique muscle in 76 specimens. The abducens nerve ended on the posterior one-third of the lateral rectus muscle in 86 specimens. If the belly of the lateral rectus muscle was divided into three superior–inferior parts, the nerve commonly entered into the middle one-third in 74 specimens. Based on the observed data, microanatomical relationships of the orbital contents were revised.     

Discussion of clinical anatomy of the lingual nerves

The tongue has various functions, such as gustation, pronunciation, mastication, and deglutition. The nerve fibers are complexly intermingled, and communications between the lingual nerve and the hypoglossal nerve have been reported. Fifteen Japanese heads (30 sides) donated to the 2nd-year students dissection course at the Nippon Dental University School of Life Dentistry, Niigata, were studied with regard to the following aspects: 1. relation of the bifurcation between the lingual and the inferior alveolar nerves close to the oval foramen; 2. distance between the oral foramen and the bifurcation of the lingual and inferior alveolar nerves; and 3. communication between the lingual and hypoglossal nerves. Three types of bifurcation were observed. The standard bifurcation was observed in 21 cases (70.1%). A high bifurcation was observed in 5 cases (16.6%), and a communicating bifurcation was observed in 4 cases (13.3%). The average distance between the oval foramen and the bifurcation of the lingual and inferior alveolar nerves was 8.7 +/- 4.2 mm (minimum: 0 mm/maximum: 14 mm). An anterior-type communication between the lingual and hypoglossal nerves was observed in 8 cases (26.6%), a posterior-type was observed in 17 cases (56.7%), and no communication was observed in 5 cases (17.7%).     

颈胸段脊柱周围重要神经结构及其毗邻关系

目的:为颈胸段脊柱选择合理的手术入路提供解剖学依据。方法:在30具尸体标本上,观察颈胸段脊柱周围重要神经结构及毗邻关系。结果:(1)喉返神经(RLN)进入气管食管沟的位置对应椎体水平及构成比,左:90%位于T3/4～T4水平,右:70%位于C6/7～C7上水平;67.7%的右RLN与颈总动脉的交叉点对应椎体水平在T1下～T1/2水平。(2)颈胸段交感干(CTST)与椎体前正中线(PVM)距离在T1椎体中点水平较C6～C7和T2～T5水平大,且男女之间差异有统计学意义(P<0.05)。(3)膈神经(PN)入胸腔后,左PN于主动脉弓前方、右PN于上腔静脉前外侧经心包与纵隔胸膜之间在肺根前方下行。结论:熟悉喉返神经、交感干和膈神经的相关解剖有助于在颈胸段脊柱手术中选择合理的手术入路。     

MRI anatomy of the nerves of the upper limb

In view of the good anatomic definition of the images obtained by magnetic resonance imaging (MRI), we have defined MRI sections allowing study of the nerves of the upper limb.     

腹股沟神经卡压征的应用解剖

目的：为腹股沟神经卡压征的防治提供解剖基础。方法：在50侧(25具)成年男性尸体标本上对腹股沟区皮神经行解剖学观测。结果：髂腹下神经皮支6％(3侧)，髂腹股沟神经皮支90％(45侧)，生殖股神经生殖支的皮支42％(21侧)，髂腹股沟神经与生殖股神经生殖支形成的吻合支12％(6侧)，生殖股神经股支的皮支8％(4侧)。结论：腹股沟区皮神经行程变异很大，解剖变异是导致神经卡压的主要原因。     

Segmental demyelination in peripheral nerves of old cats

This study of the fine structure of sciatic nerve branches in normal old cats provides evidence indicating that segmental demyelination may account, in part, for the significant decrease with age in the mean axonal conduction velocity in these hindlimb nerves. Fibers of different diameters exhibited focal abnormalities of their myelin sheath. Lipid-like droplets and granulo-vacuolar debris were present in distended portions of the inner adaxonal rim and in the outer cytoplasmic compartment of the Schwann cell. These inclusions extended into the cytoplasm of the paranodal myelin loops and clefts of Schmidt-Lantermann. There also occurred disruption of the axoglial junctions and separation of the myelin loops from the paranodal axolemma which widens the nodes of Ranvier. Complete disruption of one or more contiguous segments of the myelin sheath was produced by interlamellar splitting and ballooning along the major dense and intraperiod lines. Axonal degeneration occurred less frequently and was not present in all hindlimb nerves.     

胸神经后根的显微外科解剖

目的：为胸部选择性脊神经后根切断术(SPR术)提供可靠的后根分束的解剖学基础。方法：对成人尸体胸神经后根的自然分束和后根问神经纤维联系(CR)进行显微外科解剖学观测。结果：1条胸神经后根有4～6条根丝组成,然后形成2～4根神经亚束,最后形成上、下2股神经束。后根问神经纤维联系出现率为55．4％,根据形状可分为5型,根据位置可分为3类。结论：胸神经后根各级神经分束较易分离,神经纤维联系较为简单,有利于临床医生进行SPR术。     

脑神经海绵窦段的应用解剖

目的 :为海绵窦手术避免脑神经损伤提供解剖学依据。方法 :对 17例成年头部标本的海绵窦内脑神经的位置、走行、毗邻进行解剖学观察。结果 :动眼神经入窦点在后床突的前外侧 7.8± 2 .1mm ,在颈内动脉床突上段后方 5 .0± 2 .0mm处。滑车神经窦内段长度为 10 .1± 3 .9mm ,其走行可分为窦内直行、中份凸向眼神经、“S”型双弯曲、前 1/2段凸向眼神经 4种类型。眼神经在窦内的长度为 15 .8±6.2mm。展神经在窦内为单干者占 5 2 .9% ( 18侧 ) ;2干者占 2 9.4% ( 10侧 ) ;3干者占 17.7% ( 6侧 )。结论 :滑车神经的走行变化较大 ,经Pakinson三角行海绵窦手术时 ,应注意保护滑车神经。切开海绵窦上壁分离窦腔时 ,应注意保护经上壁入窦的动眼神经。     

喉返神经在颈部的应用解剖研究

目的　为在甲状腺手术中避免误伤喉返神经提供解剖学基础。方法　对 5 0具 (男 3 0具 ,女 2 0具 )成人尸体解剖喉返神经和甲状腺下动脉之间的关系进行解剖观测。结果　喉返神经平均横径为 ( 1.93± 0 .3 5 )mm。喉返神经入喉支以 2～ 5干型为多见 ,占 70 .0 0 %。甲状腺下动脉的直径为 ( 2 .61± 0 .2 3 )mm。喉返神经和甲状腺下动脉之间的关系 ,左右均有明显差异。结论　喉返神经横径平均在 ( 1.93± 0 .3 5 )mm之间 ;喉返神经在甲状腺峡平面分支的最为常见 ;神经位于动脉主干之后的为多见 ,占 5 4.0 0 % ;神经位于动脉前及动脉分支之间的例数相近 ,左侧神经位于动脉之后的多见 ,而右侧神经位于动脉之前的多见 ,左右有明显差异 ,为临床颈部外科手术时参考。     

The gross anatomy of the renal sympathetic nerves revisited

Catheter‐based renal denervation techniques focus on reducing blood pressure in resistant hypertension. This procedure requires exact knowledge of the anatomical interrelation between the renal arteries and the targeted renal nervous plexus. The aim of this work was to build on classical anatomical studies and describe the gross anatomy and anatomical relationships of the renal arteries and nerve supply to the kidneys in a sample of human cadavers. Twelve human cadavers (six males and six females), age range 73 to 94 years, were dissected. The nervous fibers and renal arteries were dissected using a surgical microscope. The renal plexus along the hilar renal artery comprised a fiber‐ganglionic ring surrounding the proximal third of the renal artery, a neural network along the middle and distal thirds, and smaller accessory ganglia along the course of the nerve fibers. The fibers of the neural network were mainly located on the superior (95.83%) and inferior (91.66%) surfaces of the renal artery and they were sparsely interconnected by diagonal fibers. Polar arteries were present in 33.33% of cases and the renal nerve pattern for these was similar to that of the hilar arteries. Effective renal denervation needs to target the superior and inferior surfaces of the hilar and polar arteries, where the fibers of the neural network are present. Clin. Anat. 29:660–664, 2016. © 2016 Wiley Periodicals, Inc.     

Functional anatomy of the temporomandibular joint

Summary A study of 72 temporomandibular joints of adults without any gross signs of degenerative changes was made, in order to analyse the stress on individual regions of the joint, and to determine the path of the split line pattern in the articular cartilage. The cancellous architecture and the material distribution in the juxta-articular bone were also investigated. Zones of high-density compact substance in the lateral region of the joint, and the presence of attractive singular points in the split line orientation in this localization, suggest great stress on the lateral part of the temporomandibular joint. This increased stress in the lateral region is confirmed by the fact that arthrotic changes in the temporomandibular joint first almost always appear laterally. Degenerative changes usually originate at the articular disc, affect the articular tubercle after a delay, and finally spread to the condyle. Besides the greater physiological, mechanical stress on the lateral region of the joint, the force acting on every individual temporomandibular joint is influenced by the dental condition. The molars and bicuspids serving as a support zone play a decisive role in this context.Dedicated to Professor Dr. H. Haug on the occasion of his 70th birthday     

Surgical anatomy of the pectoral nerves and the pectoral musculature

The pectoral nerves (PNs) may be selectively injured through various traumatic mechanisms such as direct trauma, hypertrophic muscle compression, and iatrogenic injuries (breast surgery and axillary node dissection, pectoralis major muscle transfers). The PN may be surgically recovered through nerve transfers. They may also be used as donors to the musculocutaneous, axillary, long thoracic, and spinal accessory nerves and for reinnervation of myocutaneous free flaps. Thus, in this article, we reviewed the surgical anatomy of PN. A meta-analysis of the available literature showed that the lateral pectoral nerve (LPN) arises most frequently with two branches from the anterior divisions of the upper and middle trunks (33.8%) or as a single root from the lateral cord (23.4%). The medial pectoral nerve (MPN) usually arises from the medial cord (49.3%), anterior division of the lower trunk (43.8%), or lower trunk (4.7%). The two PN are usually connected immediately distal to the thoracoacromial artery by the so-called ansa pectoralis. The MPN may also show communications with the intercostobrachial nerve. In 50%-100% of cases, it may pass, at least with some branches, through the pectoralis minor muscle. The LPN supplies the upper portions of the pectoralis major muscle; the MPN innervates the lower parts of the pectoralis major and the pectoralis minor muscle. Among the accessory muscles of the pectoral girdle, the LPN may also innervate the tensor semivaginae articulationis humero-scapularis, pectoralis minimus, sternoclavicularis, axillary arch, sternalis, and infraclavicularis muscles; the MPN may innervate the pectoralis quartus, chondrofascialis, axillary arch, chondroepitrochlearis, and sternalis muscles.