面、前庭蜗神经脑池段的显微外科解剖学研究

目的：探讨面、前庭蜗神经脑池段的显微外科解剖，为临床手术提供解剖学参考。方法：应用10％福尔马林固定的成人尸头标本10例（20侧），显微镜下经乙状窦后入路对面、前庭蜗神经脑池段及其毗邻结构进行解剖、观测。结果：面、前庭蜗神经脑池段分为进出脑干段（rootentry／exitzone，REZ），桥小脑角段，内耳道段。REZ有重要的解剖三角；桥小脑角段面神经运动支与前庭蜗神经走行关系恒定，走行在前庭蜗神经前上方，中间神经和面神经运动根在内耳道中部融合成一支；桥小脑池蛛网膜象袖套一样延续至内耳道底部。结论：（1）听神经瘤起源于蛛网膜下腔内，面、前庭蜗神经池与桥小脑池相连续；（2）听神经瘤可利用REZ解剖三角来寻找面、前庭蜗神经的起始段，并根据肿瘤生长方向不同与REZ的解剖关系分3种类型，有利于术中面、前庭蜗神经功能的保留；（3）磨除内耳道后唇不能超过1cm，以免进入骨迷路。     

The topographical relationships and anastomosis of the nerves in the human internal auditory canal

Introduction The anatomy of the nerves in the human internal auditory canal (IAC) has been reported by a number of authors, and there are some differences among the viewpoints of the literatures. With the development of the microsurgery and endoscopic surgery in the IAC, the study of the topographical relationship of the nerves in the human IAC becomes more and more important. The purpose of this study was to investigate the anastomosis and topographical relationship of the nerves in the human IAC. Methods In this study, we dissected 30 human temporal bones from 15 heads, and examined the topographical relationship and the anastomosis of the nerves in human IAC. Results (1) In 11 out of 30 cases (37%), the facial nerve is anterosuperior to the vestibulocochlear nerve through the whole IAC; and for the remaining 19 cases (63%), the facial nerve rotates anteroinferiorly at an angle ranging from 30° to 90°, which is in the same direction as that of the cochlear. (2) Vestibulofacial nerve anastomosis occurs in 25 cases (83%), of which 67% appears near the porus acusticus, and of which 33% appears between the lateral and intermedial portion of IAC. The diameter was about 0.5–1 mm. (3) Vestibulocochlear anastomosis occurs in 24 cases (80%) among which, some brush-like nerve fiber bundles of the cochlear nerve were seen to enter the acculus proprius directly in 13 cases. Transverse vestibulocochlear anastomosis in the fundus of internal acoustic meatus occurred in 15 cases, including two cases with more anastomosis. No vestibulocochlear nerve anastomosis was found in six cases in this study. Conclusions Our study shows that the Vestibulofacial nerve anastomosis and the vestibulocochlear nerve anastomosis do exist, and some variations appear due to individual differences. The appearance of the facial and vestibulocochlearnerves is variable but follows certain consistent patterns.     

The sinuvertebral nerves at the craniovertebral junction: A microdissection study

Bogduk et al. ( 1988 , Spine 13:2–8) noted that the joints and ligaments at the cervico‐occipital region are susceptible to whiplash injury. The upper three cervical sinuvertebral nerves (SVNs) at the craniovertebral junction (CVJ) are thought to be responsible for mediating pain from the ligaments, dura mater, and soft tissues of the posterior cranial fossa and upper cervical column. The purpose of this study was to describe in detail the origin and course of the SVNs at C0–C1, C1–C2, and C2–C3 intervertebral levels and their anterior intraspinal distribution. A sample comprising 10 adult, 12 fetal (crown rump length = 155–250 mm), and three stillborn neonatal (n = 50 sides) embalmed cadaveric cervical spines was microdissected (Carl Zeiss, Jena, Germany, 8–40× magnification). A laminectomy of the cervical spine with an occipital craniectomy (seven adult and all fetal specimens) or a horizontal section of the intervertebral levels was performed (three adult specimens) to expose the craniocervical canal. In both adult and fetal specimens, all three cervical SVNs arose from two roots, a somatic root (from the spinal nerve or ventral ramus or both) and a sympathetic root (from the vertebral artery plexus or superior cervical ganglion). The C1 and C2 SVNs were variable in number. The C2 and C3 SVN innervated most of the structures at the CVJ as well as the basiocciput region. The C1 SVN supplied a very small part of the atlanto‐occipital joint area. The intraspinal courses of all three SVNs consisted of ascending and descending branches closely adherent to the arteries of the CVJ. They supplied the dura mater, the ligaments, adjacent joints, and soft tissues by tiny branches from the main branches. The detailed origins and course are described. Clin. Anat. 2013. © 2012 Wiley Periodicals, Inc.     

Three‐dimensional imaging of the human internal acoustic canal and arachnoid cistern: a synchrotron study with clinical implications

A thorough knowledge of the gross and micro‐anatomy of the human internal acoustic canal (IAC) is essential in vestibular schwannoma removal, cochlear implantation (CI) surgery, vestibular nerve section, and decompression procedures. Here, we analyzed the acoustic‐facial cistern of the human IAC, including nerves and anastomoses using synchrotron phase contrast imaging (SR‐PCI). A total of 26 fresh human temporal bones underwent SR‐PCI. Data were processed using volume‐rendering software to create three‐dimensional (3D) reconstructions allowing soft tissue analyses, orthogonal sectioning, and cropping. A scalar opacity mapping tool was used to enhance tissue surface borders, and anatomical structures were color‐labeled for improved 3D comprehension of the soft tissues. SR‐PCI reproduced, for the first time, the variable 3D anatomy of the human IAC, including cranial nerve complexes, anastomoses, and arachnoid membrane invagination (acoustic‐facial cistern; an extension of the cerebellopontine cistern) in unprocessed, un‐decalcified specimens. An unrecognized system of arachnoid pillars and trabeculae was found to extend between the arachnoid and cranial nerves. We confirmed earlier findings that intra‐meatal vestibular schwannoma may grow unseparated from adjacent nerves without duplication of the arachnoid layers. The arachnoid pillars may support and stabilize cranial nerves in the IAC and could also play a role in local fluid hydrodynamics.     

Osteoma of the internal auditory canal

Osteomas of the internal auditory canal, inaccesible to clinical examination, are rare lesions. There are only 14 cases of osteomas and exostoses of the internal auditory canal reported in the international medical literature. A patient with an osteoma of the internal auditory canal is presented, along with differential diagnosis and possible etiologic factors for the lesion. The auditory brainsteam evoked response testing showed increased absolute latencies of 1 wave and discrepancy of the wave morphology due to bony compression of the eight nerve in the internal auditory canal. Computed tomography showed a bony growth in the internal auditory canal. Magnetic response showed no abnormalities. No surgery was performed since the symptoms improved by conservative therapy.     

Neural lateralization of vocalizations by Japanese macaques: communicative significance is more important than acoustic structure

The study was designed to determine whether the neural lateralization of vocal perception in Japanese macaques depends on the acoustic properties of the calls used or their communicative significance. Four monkeys--two Japanese macaques and two comparison macaques--were trained to discriminate among monaurally presented exemplars of two classes of vocalizations from the Japanese macaque's repertoire. Once the subjects mastered the discrimination, they performed at equivalent accuracy levels for 150 sessions. However, during this time the Japanese monkeys showed a right ear performance advantage, whereas the comparison monkeys showed no ear advantage. In order to assess whether the comparison and Japanese monkeys were attending to the same acoustic cue when performing the discrimination, a generalization test was conducted with 27 novel vocalizations. The individual monkeys' generalization gradients were highly similar and revealed that all subjects were in fact listening to the same feature of the calls. These findings, coupled with the fact that the calls were of biological significance to the Japanese monkeys alone, suggest that the laterality effect is related, in some fashion, to the communicative valence of the signals rather than their purely physical characteristics.     

The structure of the Graafian follicle as revealed by microdissection

Summary A study of the developing spleen in thirty-three embryos of the Gecko, Gymnodactylus kotschyi, revealed the fact that four phases occurred. In thefirst phase the spleen anlage appears as a plate of cells on the peritoneal surface of the dorsal mesentery, just above the primordial stomach. Thesecond phase shows the spleen as a brick-shaped protuberance in which the first capillaries (believed to be arterial) appear. The blood drains through the dorsal pancreas to enter the ductus venosus. Thethird phase shows the spleen as an oval with a more extensive system of capillaries which still seem to be arterial in nature. The blood still drains into the dorsal pancreas, thence to the ductus venosus. Thefourth phase persists to the time of hatching and reveals a change in the circulatory system of the spleen. The capillaries within the spleen are of two sizes. Those closest to the splenic artery are smaller in diameter than those which lead to the splenic vein. The former seem to be arterial and the latter venous in type. The splenic vein enters the ductus venosus direct. The intermediate pathway through the pancreas has now been dicontinued. The cells of the spleen are very small and almost entirely nuclear in the later embryonic stages.

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Zusammenfassung Eine Untersuchung über die Entwicklung der Milz von 33 Embryonen des Gecko (Gymnodactylus kotschyi) zeigt, daß der Vorgang in vier Zeitabschnitten stattfindet.In demersten Abschnitt erscheint die Anlage der Milz als eine Platte von Zellen an der peritonealen Oberfläche des dorsalen Mesenteriums, nahe über dem primordialen Magen.Während deszweiten Abschnittes erscheint die Milz in der Form einer ziegelsteinartigen Hervorragung in welcher die ersten Capillaren (wahrscheinlich arterielle Capillaren) zum Vorschein kommen. Das Blut geht durch die dorsale Pankreas und tritt in den Ductus venosus ein.Derdritte Abschnitt zeigt die Milz als ein Oval mit einem weitverzweitgten Capillarsystem, welches noch immer arteriell zu sein schcint. Das Blut nimmt denselben Weg im zweiten Abschnitt.Dervierte Abschnitt dauert bis zum Zeitpunkt des Ausschlüpfens und gibt einen Einblick in die Veränderung des Blutkreislaufs der Milz. Die Capillaren in der Milz sind von zweierlei Größe. Die Capillaren in der Nähe der Milzarterie sind kleiner als die, welche in die Vene führen. Die ersteren scheinen arteriell zu sein, während die letzteren veneus sind. Die Vene der Milz tritt direkt in den Ductus venosus ein. Der Umweg durch die Pankreas ist nun vermieden. Die Zellen der Milz sind sehr klein und bestehen in späteren embryonischen Stufen beinahe nur aus dem Zellkern.

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Membrane potential of squid axons: effect of internal and external ion concentration

Transmembrane resting potentials of squid axons were measured with variation of intracellular salt concentrations. It was found that the dependence of resting potential on the extracellular K-ion concentration was practically unaffected by the change of ionic strength in the intracellular phase, and the relationship of membrane potential and the logarithm of extracellular K-ion concentration was a straight line with a slope of about 50 mV/10-fold extracellular K-ion concentration. Also, the degree of change in resting potential due to the change of intracellular K-ion concentration was not affected appreciably by the extracellular solution with various K-ion concentrations, and the membrane potentials were insensitive over a wide range of intracellular K-ion concentrations. It was also indicated that the observed transmembrane potentials are not explained by a conventional membrane potential theory.     

下颌神经管的解剖结构

背景:在下颌后牙种植术中,由于下颌神经管走行于下颌骨体内,有时可损伤下齿槽神经,因而制约了牙种植术的应用。 因此,牙种植术的应用需详细了解下颌神经管的解剖结构。 目的：观察下颌神经管在下颌骨内的走行及管内的解剖结构。 方法：共纳入15具成人牙下颌骨标本与4具新鲜下颌骨动脉灌注标本。纳入对象均牙列完整,后牙无缺失,牙槽骨无吸收。测量15具成人牙下颌骨标本下颌管走行及其管腔各径长度,包括下颌管横径与纵径,下颌管至上下内外缘距离。观察4具新鲜下颌骨动脉灌注标本管内下颌神经管内神经、血管位置关系。 结果与结论：下颌管内缘至舌侧骨板的距离比下颌管外缘至颊侧骨板距离短(P < 0.01);下颌管上缘至牙槽嵴顶的距离较下颌管下缘至下颌骨下缘的距离大(P < 0.01)。表明下颌管在下颌骨体部走行中偏舌侧、偏下颌骨下缘。下颌神经管在下颌骨体部的部分横径小于纵径(P < 0.05),亦即下颌管截面形态为上下径略长的椭圆形。神经管横纵径于前后牙位区差异无显著性意义。实验还发现在暴露的下颌管腔中下牙槽神经及伴随血管有一层被膜包绕成神经血管束,血管位于神经上方,而且位置恒定,并发出小分支包绕神经。结果提示,下牙槽血管神经束在下颌管内走行中血管位于神经之上。