家兔跖肌肌内神经、运动终板及肌梭的分布

目的 :探究家兔跖肌肌内神经、运动终板及肌梭的分布。方法 :改良Sihler’s染色法、乙酰胆碱酯酶染色法及HE染色法。结果 :肌的起端 ,神经主干上发出若干细小分支 ,尤以内侧部为多 ;肌的中上部 ,可见 2～ 4条“L”形初级支 ,分布到内侧部肌纤维 ;3～ 5条初级支 ,穿越肌内腱膜板后司外侧部肌纤维。运动终板呈线状排列于跖肌两缘 ,矢状和冠状切面上可见“V”形终板带 ,横断面上呈“S”型。肌梭密度为 (16 .94± 1.72 )个 / g。 结论 :家兔跖肌的肌内神经、运动终板和肌梭分布与肌纤维排列有关 ;肌内神经分支密集的部位 ,运动终板聚集呈带状 ,肌梭密度高 ;跖肌具有划分亚部的特征。     

家兔半膜肌肌构筑、肌内神经和运动终板分布

目的探究家兔半膜肌的肌构筑与肌内神经和运动终板分布的关系。方法用肌构筑法、改良SihlerWs染色法、乙酰胆碱酯酶染色法对家兔半膜肌肌构筑、肌内神经和运动终板可分布进行观察。结果家兔半膜肌为长肌。肌重(3.31±0.03)g,肌长(5.45±0.09)cm,肌纤维长(3.00±0.01)cm,肌生理横切面积(1.04±0.01)cm2,FL/CSA为2.88,CSA/MW为0.31。支配家兔半膜肌的神经分3条干入肌,即上、中、下干。上干主要支配上1/3的肌束;中干分布到肌的中上部;下干沿途发出的分支最多,司中下部的肌束。中干和下干的分支之间有吻合。肌表面上、中、下部都有线状排列的运动终板短带,尤以肌下部较密。结论家兔半膜肌是长肌,倾向于速度型构筑设计;肌内神经分支密集区,运动终板分布密集;肌内神经和运动终板的分布与肌纤维排列有关。     

人冈上肌肌形态、肌内神经和肌梭分布的研究

目的为进一步探讨冈上肌的生理功能和临床应用提供形态学依据。方法大体解剖法、改良的Sihler＇s肌内神经染色法、HE染色法。结果（1）肌中部有一白色腱板,肌束呈辐凑状排列于腱板周围,似环羽肌。（2）肌内有三支初级神经支,其中肌中支最粗大,支配范围最广。在肌中部多形成交通支。（3）冈上肌的平均肌梭密度为63．94±4．73个／cm^3。结论（1）冈上肌是环羽肌,倾向力量型设计。（2）神经分支主要分布在肌内腱板的深面,在肌中部多形成神经交通支。（3）冈上肌与三角肌可构成“平行肌组”。     

家兔不同形态骨骼肌的肌内神经分布

目的探讨家兔不同形态骨骼肌的肌内神经分支分布。方法肌构筑法和改良的Sihler肌内神经染色法。结果清楚显示扁形的胸大肌接受胸前神经和胸后神经支配。胸前神经主要支配横行纤维,并在其中部形成—“U”形的神经襻。胸后神经主要支配斜行纤维,与前者的神经细分支间有吻合;羽状的跖肌由胫神经肌支支配,入肌后逐渐向肌的内、外两侧发出许多初级神经支,这些神经支又分出若干树枝状的次级支与细分支;梭形的趾长伸肌,有2条肌外神经干,上千及其分支支配止于第二趾的肌纤维,下干支配其余3趾的肌纤维。结论不同形态肌的肌内神经分支、分布与肌纤维排列有关;肌内神经分支走行有与肌束平行和,或垂直两种形式。     

家兔趾长伸肌肌内神经、运动终板和肌梭的分布

目的：探究家兔趾长伸肌肌内神经、运动终板与肌梭的分布。方法：改良Sihler’s染色法、乙酰胆碱酯酶染色法及HE染色法。结果：趾长伸肌是短肌束构成的长肌,肌束起点高的,止点相应亦较高。连于第2趾的肌纤维占据了肌腹上1／3,止于其余3趾的肌纤维位于下2／3。趾长伸肌的神经来自2条肌外神经干,上支及其分支支配第2趾的肌纤维,下支司其余3趾。运动终板分布除冠状切面上为弥漫的黑色颗粒外,其余各切面均为一条连续的运动终板带。各部的肌梭密度分别是：起端33.95个／g、肌腹中部44.76个／g、止端为零。结论：家兔趾长伸肌内,肌梭分布不均匀。肌内神经分支密集的部位,运动终板集聚、肌梭密度亦高。家兔趾长伸肌具有划分亚部的特征。     

腘肌肌构筑和肌内神经的研究

目的　探讨腘肌肌构筑学特征和肌内神经分支分布特点。 方法 大体解剖法、肌构筑法、改良Sihler’s 染色法。 结果　腘肌为三角形扁肌,肌中间有两块并排的冠状位腱板。肌重(15.13±0.41) g,肌长(9.09±0.31) cm,肌纤维长(1.93±0.09) cm,羽状角（11.5±0.82）°,肌生理横切面积(7.17±0.13) cm2。支配腘肌的神经于该肌外侧缘入肌,入肌后分成上、下支2支,上支较细,支配该肌前上部,下支较粗,支配该肌前下部和后部。 结论　 腘肌是羽肌,倾向力量型设计,肌内神经主要分布于肌的中下部。     

腹直肌形态与肌内神经分布研究及其临床意义

目的:通过对腹直肌形态学、神经入肌点和肌内神经分支分布的研究,为腹直肌的临床肌移植提供形态学资料.方法:大体解剖法和改良Sihler's肌内神经染色法.结果:(1)腹直肌肌重(47.80±12.89)g,肌长(33.18±3.38)cm,肌宽(4.55±1.87)cm,肌厚(0.55±0.24)cm,腱划长(1.06±0.32)cm.(2)腹白:肌神经入肌点在肌深面肌宽的中、外1/3交界处,自上而下呈线形排列.(3)腹直肌受第7～12胸神终前支和第1腰神经前支支配,呈节段性、重替性分布.神经主干和分支在肌内走行不受腱划分隔的影响.结论:腹直肌由多神经节段性重叠性支配,神经在肌内的行程不受腱划影响.腹直肌的神经入肌点在肌深面肌宽的中、外1/3交界处.     

人股直肌肌构筑、肌梭分布与亚部化

目的:研究人股直肌肌构筑特征,肌梭的分布部位、范围及密度,进一步探讨股直肌的亚部划分,为临床外科提供肌形态学资料.方法:用大体解剖法观察20具尸体股直肌的肌构筑学特征;用组织学H-E染色法研究5具尸体股直肌肌梭分布.结果:股直肌是由短肌纤维和肌内腱板构成的羽肌,肌质量（158.7±10.5）g,肌长（30.2±2.0）cm,肌纤维长(6.7±1.8)cm,羽状角17.1°±2.3°,肌节长（2.03±0.07）cm,生理横切面积（22.38±3.10）cm2;股直肌肌梭平均密度为19.38个/克.结论:股直肌的上部比其中、下部肌梭密度高;根据股直肌的肌构筑特征结合肌内神经分支分布,进一步证实股直肌可分为外上和内下两个亚部,可考虑进行亚部化取材用于肌移植.     

趾长屈肌的亚部化研究及其临床意义

目的　探讨趾长屈肌的亚部划分，为临床外科“半肌”移位手术提供解剖学基础。 方法　大体解剖法、肌构筑法、改良Sihler’s 染色法。 结果　①可依劈开趾长屈肌肌内腱板，把该肌分为胫侧和腓侧两个亚部；②胫侧亚部各构筑学值大于腓侧亚部；③两亚部存在单独神经支配。 结论　①趾长屈肌可分为胫侧亚部和腓侧亚部，两亚部有独立的神经支配；②趾长屈肌的两个亚部均为半羽肌，胫侧亚部产生的肌力大于腓侧亚部。     

前锯肌的应用解剖学研究

目的研究前锯肌的构筑学特征和肌内神经分布特点,为临床应用前锯肌提供解剖学基础。方法大体解剖法、肌构筑法、改良Sihler’s肌内神经染色法。结果 1)前锯肌上部肌纤维长(6.40±0.61)cm,生理横切面积(6.30±0.50)cm~2,中部肌纤维长(9.68±1.57)cm,生理横切面积(5.08±0.39)cm~2,下部肌纤维长(12.97±1.39)cm,生理横切面积(5.79±0.79)cm~2;(2)前锯肌由胸长神经支配,该神经在前锯肌上部和中部分别发出4~6和7~9支分支,在下部发出分支较少,仅2~3支。结论 (1)前锯肌的上、中部肌纤维是拉拢肩胛骨靠向胸壁的主要力量;(2)前锯肌下部肌内神经分布较少,肌齿多,可用于临床肌移植。     

胸锁乳突肌亚部肌构筑、肌梭和神经入肌点定位

目的:为胸锁乳突肌亚部的临床应用提供形态学依据。方法:肌构筑法,组织学HE染色和体视学法。结果:(1)胸骨头亚部的肌重与生理横切面积分别是锁骨头两亚部之和的1.39倍与1.33倍;锁骨头深亚部的肌纤维长仅为胸骨头亚部肌纤维长的82%。(2)胸骨头亚部和锁骨头浅亚部的肌梭密度显著小于锁骨头深亚部。(3)副神经胸锁乳突肌支绕锁骨头深亚部后缘(占65%)入肌时距乳突尖(4.39±0.42)cm,而穿锁骨头深亚部(占35%)入肌时距乳突尖(3.96±0.34)cm。结论:胸骨头亚部是胸锁乳突肌肌力的主要提供者。锁骨头深亚部更多参与维持头部姿势。     

Muscle fibre types and their distribution in the biceps and triceps brachii of the rat and rabbit

Muscle fibre type composition and distribution in the biceps brachii (long head) and triceps brachii (long head) of the rat and rabbit were investigated using the following histochemical techniques: myosin ATPase, with preincubation at pH 10.4 and 4.35; succinate dehydrogenase (SDH) and glycogen phosphorylase. The muscle fibres were classified into slow-twitch (SO), fast-twitch glycolytic (FG), fast-twitch oxidative glycolytic (FOG and FOg) and fast-twitch oxidative fibres (FO). Significant differences in the regional distribution of muscle fibre types have been observed between the rat and the rabbit. In the rat, SO fibres were restricted to the deep regions of both biceps and triceps brachii, whereas FG fibres were located in the intermediate and superficial regions (the superficial regions contained the highest percentages of FG fibres). In the rabbit, SO and FG fibres were spread over the entire muscle, although SO and FG fibres were most abundant in the deep and superficial regions respectively. These findings indicate that the biceps and triceps brachii are more regionalised in the rat than in the rabbit.     

妊娠及分娩对盆底肌力的影响

目的比较妊娠及分娩后妇女和正常妇女的盆底肌力,了解妊娠及分娩对盆底肌力的短期影响。方法将183例在本院就诊的孕产妇分为顺产组和剖宫产组,使用盆底肌电生理仪分别检测其产前及产后盆底肌肌力,并与166例正常妇女进行评估及比较。结果妊娠组盆底肌力与正常组比较明显降低,差异有统计学意义（P〈0.05）;妊娠组和正常组中的Ⅰ类与Ⅱ类肌纤维肌力均降低,但差异无统计学意义（P〉0.05）;产后6～8周顺产组盆底肌力较剖宫产组肌力明显降低,差异有统计学意义（P〈0.05）;产后12～14周顺产组盆底肌力与剖宫产组盆底肌力均降低,差异无统计学意义（P〉0.05）。结论顺产及选择性剖宫产对盆底肌肌力的影响在产后3个月无明显差异。     

Structure, distribution and innervation of muscle spindles in avian fast and slow skeletal muscle

Muscle spindles in 2 synergistic avian skeletal muscles, the anterior (ALD) and posterior (PLD) latissimus dorsi, were studied by light and electron microscopy to determine whether morphological or quantitative differences existed between these sensory receptors. Differences were found in the density, distribution and location of muscle spindles in the 2 muscles. They also differed with respect to the morphology of their capsules and intracapsular components. The slow ALD possessed muscle spindles which were evenly distributed throughout the muscle, whereas in the fast PLD they were mainly concentrated around the single nerve entry point into the muscle. The muscle spindle index (number of spindles per gram wet muscle weight) in the ALD was more than double that of its fast-twitch PLD counterpart (130.5±2.0 vs 55.4±2.0 respectively, n=6). The number of intrafusal fibres per spindle ranged from 1 to 8 in the ALD and 2 to 9 in the PLD, and their diameters varied from 5.0 to 16.0 μm and 4.5 to 18.5 μm, respectively. Large diameter intrafusal fibres were more frequently encountered in spindles of the PLD. Unique to the ALD was the presence of monofibre muscle spindles (12.7% of total spindles observed in ALD) which contained a solitary intrafusal fibre. In muscle spindles of both the ALD and PLD, sensory nerve endings terminated in a spiral fashion on the intrafusal fibres in their equatorial regions. Motor innervation was restricted to either juxtaequatorial or polar regions of the intrafusal fibres. Outer capsule components were extensive in polar and juxtaequatorial regions of ALD spindles, whereas inner capsule cells of PLD spindles were more numerous in juxtaequatorial and equatorial regions. Overall, muscle spindles of the PLD exhibited greater complexity with respect to the number of intrafusal fibres per spindle, range of intrafusal fibre diameters and development of their inner capsules. It is postulated that the differences in muscle spindle density and structure observed in this study reflect the function of the muscles in which they reside.     

Effect of single and periodic contusion on the rat soleus muscle at different stages of regeneration

This work analyzed the rat soleus muscle after single and recurrent contusions at different stages of regeneration. A noninvasive contusion was produced by a type of drop‐mass equipment. The posterior region of the right hind limb received a trauma and both right and left soleus muscles were analyzed 1, 4, and 6 days after a single contusion (1×), and 6 and 30 days after periodic contusions (10×, one trauma per week for 10 weeks). Single contusion: there was no significant difference between right and left soleus muscle weight. All animals showed abundant signs of acute damage in the right soleus. AChE activity was identified in regeneration segments of the right soleus. Periodic contusions: there was an increase in the right soleus muscle weight (α = 5%) only in the animals evaluated 6 days after periodic contusions. The right soleus muscle showed a high incidence of chronic signs of damage, such as split fibers and a centralized nucleus, which predominated when compared with the acute signs. Right soleus muscles showed split fibers with AChE activity in both the proximal and middle regions. There was no difference in the incidence of muscle fiber types (I, II, and IIC) between right and left soleus muscles after periodic contusions. Skeletal muscle contusion is common in humans, especially in sport activities, where repetitive traumas are also frequent. The results of this work indicate that despite the regeneration process there is an important change in the morphological aspect of regenerated muscle fibers, which possibly affect muscle performance. Anat Rec 254:281–287, 1999. © 1999 Wiley‐Liss, Inc.     

The human temporalis muscle: Superficial,deep, and zygomatic parts comprise one structural unit

The structure of the temporalis muscle was examined in detail from cadaveric specimens (32 specimens from 16 subjects: 5 males, average age 80.6 years; 11 females, average age 88.6 years) and Computerized Tomography (CT) and T1‐weighted Magnetic Resonance (MR) images from normal clinical patients (10 females: average age 45.0 years). Three parts of the muscle were clearly delineated in all cadaveric specimens: (1) the classically recognized superficial part, (2) a zygomatic part, and (3) a complex deep part. In one female specimen, the superficial temporalis demonstrated extensive insertions into the zygomatic process and temporomandibular joint. The zygomatic temporalis originates from the zygomatic arch to insert into the superficial part of the temporalis as it inserts into the lateral surface of the coronoid process. In all specimens, the deep temporalis contained muscle bundles that originated from various crests along the anterior surface of the temporal fossa and inserted into the internal aspect of the coronoid process and retromolar triangle, interdigitating with the buccinator, mylohyoid, and superior constrictor muscles. The confluence of muscle fibers into the buccinator muscle was confirmed in all CT/MRI images. The deep and zygomatic parts described were regarded as accessory muscle bellies previously, but are demonstrably part of the temporalis muscle as a whole. Clin. Anat. 22:655–664, 2009. © 2009 Wiley‐Liss, Inc.     

The importance of frequency and amount of electrical stimulation for contractile properties of denervated rat muscles

Soleus (SOL) and extensor digitorum longus (EDL) muscles were denervated and directly stimulated for 23–69 days through implanted electrodes employing three different patterns. The stimulation was delivered in impulse trains where the pulse frequency differed (20, 75, and 150 Hz), while the train duration (0.3 s) and train repetition rate (1 min^-1) were identical. Consequently, the number of pulses varied such that higher frequency was combined with a higher amount of stimulation. In both SOL and EDL the high-frequency pattern resulted in shorter twitch time-to-peak, greater post-tetanic potentiation, and greater tetanic force than the low frequency. Isotonic shortening velocity was increased to the same extent by all the patterns in SOL whereas in EDL fast intrinsic shortening velocity was maintained by the low-frequency pattern while it was decreased by the high-frequency pattern. We attribute this unexpected effect on the EDL to the larger number of pulses in the high-frequency pattern. By combining the present findings with previous data on directly stimulated rat muscles we conclude: in SOL the twitch duration is influenced by both the frequency and the amount of impulse activity, higher frequencies and smaller amounts leading to faster twitches. The EDL twitch duration is similarly dependent on the amount of activity, but the role of frequency is more unclear. In both SOL and EDL the isotonic shortening velocity is reduced by increasing amounts of activity and there is no evidence that impulse frequency plays a role. In EDL force output is strongly influenced by the impulse frequency, low frequencies resulting in low force outputs irrespective of the amount of activity.     

Feasibility,accuracy and safety of a percutaneous fine‐needle biopsy technique to obtain qualitative muscle samples of the lumbar multifidus and erector spinae muscle in persons with low back pain

The lumbar muscular system, in particular the lumbar multifidus muscle (LM) and the erector spinae muscle (ES), plays an important role in stabilizing and mobilizing the lumbar spine. Based on the topography, the lumbar paraspinal muscles can be classified into local and global muscles. LM is part of the local system, whereas ES is part of the global system. Therefore, it is interesting to investigate the muscle fibre type composition in both muscles. There is accumulating evidence that nonspecific chronic low back pain is associated with lumbar muscle dysfunction. To further elucidate this lumbar paraspinal muscle dysfunction, it is important to understand the structural characteristics of individual muscle fibres of LM and ES. Muscle fibre type composition can be investigated in muscle tissue samples. So far, muscle samples are taken by using invasive procedures that are not well tolerated. The aim of this article was to evaluate the feasibility, accuracy and safety of a percutaneous fine‐needle biopsy technique to obtain muscle samples from LM and ES in persons with nonspecific chronic low back pain and to evaluate the feasibility of performing immunofluorescence analysis of myosin heavy chain isoform expression to investigate muscle fibre type composition. Preliminary investigations in cadavers were performed to determine the optimal vertebral level and puncture site to obtain muscle samples of LM and ES through a single skin puncture. In 15 persons with nonspecific chronic low back pain, muscle samples of LM and ES were taken under local anaesthesia with the percutaneous fine‐needle biopsy technique, preceded by determination of the puncture site with ultrasonography. Muscle fibre type composition was investigated using immunofluorescence analysis of myosin heavy chain expression. The subjects reported little or no pain and were willing to repeat the procedure. The obtained muscle tissue contained transverse‐sectioned muscle fibres in which muscle fibre contractile characteristics of the paraspinal muscles could be evaluated with immunofluorescence analysis of the myosin heavy chains. We can conclude that percutaneous microbiopsy appears to be feasible and accurate, and safe to use to obtain muscle tissue from the paraspinal muscles. The use of ultrasonography to determine the puncture site is necessary to ensure biopsy of the correct muscles and to ensure the safety of the procedure.     

Mechanisms of muscle growth and atrophy in mammals and Drosophila

Background: The loss of skeletal muscle mass (atrophy) that accompanies disuse and systemic diseases is highly debilitating. Although the pathogenesis of this condition has been primarily studied in mammals, Drosophila is emerging as an attractive system to investigate some of the mechanisms involved in muscle growth and atrophy. Results: In this review, we highlight the outstanding unsolved questions that may benefit from a combination of studies in both flies and mammals. In particular, we discuss how different environmental stimuli and signaling pathways influence muscle mass and strength and how a variety of disease states can cause muscle wasting. Conclusions: Studies in Drosophila and mammals should help identify molecular targets for the treatment of muscle wasting in humans. Developmental Dynamics 243:201–215, 2014. © 2013 Wiley Periodicals, Inc.