树鼩(Tupaia belangeri chinensis)的脑底动脉环

用25只树鼩,从升主动脉灌注带色的橡胶乳液,在解剖显微镜下进行解剖观察,用目测微尺进行测量。大多数树鼩(22只)有完整的脑底动脉环。由左、右大脑前动脉向内侧各发一前交通动脉组成大脑前总动脉。前交通动脉口径为大脑前动脉的75～85％。后交通动脉口径与大脑后动脉相近,连于颈内动脉与大脑后动脉(基底动脉的分支)之间。测量了组成脑底动脉环有关动脉的口径。由于后交通动脉足够粗大,只有中断左、右颈总动脉和左、右椎动脉,才能造成全脑缺血。     

Anatomy of the sinoatrial node and the supply of its vascularization in man

Seventy heart preparations of persons belonging to different sex and age have been investigated, using a complex of anatomical and histological techniques. The dimensions of the sinoatrial node (SAN) vary with age and depend on various size and form of the heart. The large atrial branch of the right and left coronary arteries supplies mainly the SAN with blood. More seldom the atrial branches of both cardiac arteries, having anastomoses, realize the SAN blood supply. The character of the SAN vascularization depends on branching variations of the atrial vessels. At the right coronary variant the sources of the SAN blood supply are the SAN branch, the right intermediate or right posterior atrial branches, and at the left coronary variant--the anterior left, the posterior left and the intermediate left atrial branches. At the even variant the SAN blood supply sources are the right intermediate and the anterior left atrial or the right posterior and the left posterior atrial branches. The data obtained can be used for comparison with the results of coronography to make a skilled analysis of clinical-roentgenological observations.     

The upper esophageal sphincter in the cat: the role of central innervation assessed by transient vagal blockade

Studies were performed on four cats to assess the role of extrinsic innervation via the cervical nerve trunks in the control of upper esophageal sphincter function. Transient vagal nerve blockade was accomplished by cooling the cervical vagosympathetic nerve trunks previously isolated in skin loops on each side of the neck. Upper esophageal sphincter pressure was measured using a multilumen oval manometry tube and a rapid pull-through technique. The upper esophageal sphincter response to cervical intraesophageal balloon distention and acid perfusion was assessed. The feline upper esophageal sphincter has a distinct asymmetric pressure profile, whereby anterior pressure greater than posterior pressure greater than left pressure greater than right pressure. Bilateral vagal nerve blockade lowered the mean upper esophageal sphincter pressure from 18.5 +/- 1.5 to 12.0 +/- 2.8 mmHg (1 mmHg = 133.3 Pa) (p less than 0.001), with a significant reduction in pressure in all four quadrants. Intraesophageal balloon distention and acid perfusion both produced a significant increase in upper esophageal sphincter pressure. Bilateral vagal nerve blockade completely abolished the response of the upper esophageal sphincter to balloon distention and acid perfusion. We conclude that normal upper esophageal sphincter tone in the cat is partially mediated by excitatory neural input via the cervical nerve trunks, presumably via the recurrent laryngeal nerves; and cervical intraesophageal balloon distention and acid perfusion produce reflex contraction of the upper esophageal sphincter, which is dependent on neural pathways via the cervical vagal nerve trunks, but the relative contribution of afferent and efferent pathways remains unknown.     

Distributing and delivering vessels of the human heart

The branching characteristics of the right coronary artery, acute marginal, posterior descending, left anterior descending, circumflex, and obtuse marginal arteries are compared with those of diagonal branches, left and right ventricular branches, septal, and higher-order branches, to test a newly proposed functional classification of the coronary arteries in which the first group rank as distributing vessels and the second as delivering vessels. According to this classification, the function of the first type is merely to convey blood to the borders of myocardial zones, while the function of the second is to implement the actual delivery of blood into these zones. This functional difference is important in the hemodynamic analysis of coronary heart disease, as it provides an assessment of the role of a vessel within the coronary network and hence an assessment of the functional importance of that vessel in a particular heart. Measurements from casts of human coronary arteries are used to examine the relevant characteristics of these vessels and hence to test the basis of this classification.     

Elevation of plasma gastrin and pancreatic polypeptide by electrical vagal stimulation in sheep: effects of sequential stimulation

Gastrin and pancreatic polypeptide (PP) are released into the circulation by vagal stimulation. The individual effects of the anterior and posterior vagal trunks on the release of these peptides are unknown. Four sheep were anaesthetized and studied acutely: both vagi were dissected at the hiatus and the trunks divided. In two sheep, the distal ends of the anterior trunks were stimulated for 5 min with an 8 V, 1 ms impulse at 10 Hz. After 1 h the posterior trunks were stimulated similarly. In the other two sheep, the posterior trunk was stimulated and after 1 h the anterior vagal trunk was stimulated. The anterior and posterior trunk equally stimulated the release of both gastrin and PP in four animals. The second stimulation in these four animals resulted in an 18-fold greater integrated response of gastrin and 20-fold greater response of PP. This potentiation to the second stimulus was observed in further experiments even when the same trunk, posterior or anterior, was stimulated twice. The similarity of influence of the anterior and posterior trunks for the release of PP suggests the existence of mechanisms for vagally stimulated PP release other than branches direct from the vagal trunks.     

金钱豹和猪獾冠状动脉的解剖

为了阐明金钱豹(Panthera pardus)和猪獾(Arctonyx collaris)心冠状动脉的分支分布特征及血供情况,为心脏生物学及动物学研究提供结构基础资料,利用血管铸型和组织透明方法观察研究了金钱豹与猪獾心左、右冠状动脉的分支分布.结果表明,金钱豹和猪獾的心均由左右冠状动脉营养.金钱豹左冠状动脉分为室间隔支、前降支和旋支.前降支又分出左室上支、左室中支和左室下支.右冠状动脉沿途分出右室前支、右室后下支和右室后上支.猪獾左冠状动脉分为前降支和旋支.前降支又分出室间隔支和左室前支,旋支又分出左缘支和左室后支.其右冠状动脉沿途分出右室前支、右缘支和右室后支.金钱豹和猪獾心的室间隔均由发自左冠状动脉的独立的室间隔支营养,二者左右冠状动脉在膈壁的分布属于均衡型.     

Changes in Oral Apparatus Structure Accompanying Vacuolar Formation in the Macrostomal Form of Tetrahymena vorax. A Model for the Formation of Food Vacuoles in Tetrahymena1

The large cytopharyngeal pouch of the macrostomal form of Tetrahymena vorax, following the addition of calcium, can form a sealed, empty vacuole. The open cytostomal region of this cell, which averages about 16 μ in diameter, is closed by an upward (ventral) movement of the right and posterior ribbed walls, both of which project into the cytostomal cavity. At the same time, the anterior and left walls of the cytostome-cytopharyngeal complex move to the right, forming a diagonally (right to left) placed furrow in the floor of the buccal cavity as these walls meet. As a result of the movement, the edges of the single membrane-bounded cytopharyngeal pouch are brought together and fuse, producing the closed vacuole. Elements of the cytoskeleton appear to participate in the closure process. Three major groups of ribbed wall microtubules support the open cytostome. The anterior ribbed wall microtubules pass laterally along the anterior (dorsal) portion of the cytopharyngeal pouch to the left where they end in the specialized cytoplasm. Middle oral rib microtubules terminate at the right and posterior margin of the cytopharynx while microtubules from the most posterior region of the ribbed wall pass to the left terminating in the specialized cytoplasm. The fine filamentous reticulum, a striated reticulum that borders the right, posterior, and anterior margins of the cytostome-cytopharyngeal complex, is in an ideal position to participate in these movements. It is anchored anteriorly high up in the buccal cavity to the cross-connective between the third membranelle and the undulating membrane complex. It courses beneath the right and posterior ribbed walls and runs laterally along the anterior margin of the cytopharynx to the left side. Contraction or pulling of this reticulum would act to bring the microtubule-reinforced walls of the cytopharynx together permitting fusion of the cytopharyngeal pouch membranes to form a sealed vacuole.     

Parasympathetic control of the heart. I. An interventriculo-septal ganglion is the major source of the vagal intracardiac innervation of the ventricles.

The locations, projections, and functions of the intracardiac ganglia are incompletely understood. Immunocytochemical labeling with the general neuronal marker protein gene product 9.5 (PGP 9.5) was used to determine the distribution of intracardiac neurons throughout the cat atria and ventricles. Fluorescence microscopy was used to determine the number of neurons within these ganglia. There are eight regions of the cat heart that contain intracardiac ganglia. The numbers of neurons found within these intracardiac ganglia vary dramatically. The total number of neurons found in the heart (6,274 +/- 1,061) is almost evenly divided between the atria and the ventricles. The largest ganglion is found in the interventricular septum (IVS). Retrogradely labeled fluorescent tracer studies indicated that the vagal intracardiac innervation of the anterior surface of the right ventricle originates predominantly in the IVS ganglion. A cranioventricular (CV) ganglion was retrogradely labeled from the anterior surface of the left ventricle but not from the anterior surface of the right ventricle. These new neuroanatomic data support the prior physiological hypothesis that the CV ganglion in the cat exerts a negative inotropic effect on the left ventricle. A total of three separate intracardiac ganglia innervate the left ventricle, i.e., the CV, IVS, and a second left ventricular (LV2) ganglion. However, the IVS ganglion provides the major source of innervation to both the left and right ventricles. This dual innervation pattern may help to coordinate or segregate vagal effects on left and right ventricular performance.     

The neuronal correlates of digits backward are revealed by voxel-based morphometry and resting-state functional connectivity analyses

Digits backward (DB) is a widely used neuropsychological measure that is believed to be a simple and effective index of the capacity of the verbal working memory. However, its neural correlates remain elusive. The aim of this study is to investigate the neural correlates of DB in 299 healthy young adults by combining voxel-based morphometry (VBM) and resting-state functional connectivity (rsFC) analyses. The VBM analysis showed positive correlations between the DB scores and the gray matter volumes in the right anterior superior temporal gyrus (STG), the right posterior STG, the left inferior frontal gyrus and the left Rolandic operculum, which are four critical areas in the auditory phonological loop of the verbal working memory. Voxel-based correlation analysis was then performed between the positive rsFCs of these four clusters and the DB scores. We found that the DB scores were positively correlated with the rsFCs within the salience network (SN), that is, between the right anterior STG, the dorsal anterior cingulate cortex and the right fronto-insular cortex. We also found that the DB scores were negatively correlated with the rsFC within an anti-correlation network of the SN, between the right posterior STG and the left posterior insula. Our findings suggest that DB performance is related to the structural and functional organizations of the brain areas that are involved in the auditory phonological loop and the SN.     

Identifying the Source of a Humoral Factor of Remote (Pre)Conditioning Cardioprotection

Signalling pathways underlying the phenomenon of remote ischaemic preconditioning (RPc) cardioprotection are not completely understood. The existing evidence agrees that intact sensory innervation of the remote tissue/organ is required for the release into the systemic circulation of preconditioning factor(s) capable of protecting a transplanted or isolated heart. However, the source and molecular identities of these factors remain unknown. Since the efficacy of RPc cardioprotection is critically dependent upon vagal activity and muscarinic mechanisms, we hypothesized that the humoral RPc factor is produced by the internal organ(s), which receive rich parasympathetic innervation. In a rat model of myocardial ischaemia/reperfusion injury we determined the efficacy of limb RPc in establishing cardioprotection after denervation of various visceral organs by sectioning celiac, hepatic, anterior and posterior gastric branches of the vagus nerve. Electrical stimulation was applied to individually sectioned branches to determine whether enhanced vagal input to a particular target area is sufficient to establish cardioprotection. It was found that RPc cardioprotection is abolished in conditions of either total subdiaphragmatic vagotomy, gastric vagotomy or sectioning of the posterior gastric branch. The efficacy of RPc cardioprotection was preserved when hepatic, celiac or anterior gastric vagal branches were cut. In the absence of remote ischaemia/reperfusion, electrical stimulation of the posterior gastric branch reduced infarct size, mimicking the effect of RPc. These data suggest that the circulating factor (or factors) of RPc are produced and released into the systemic circulation by the visceral organ(s) innervated by the posterior gastric branch of the vagus nerve.     

Morphology of diaphragm in the crab-eating monkey (Macaca fascicularis)

The diaphragm was studied in 30 adult crab-eating monkeys (Macaca fascicularis). The muscular bundle of the lumber part was derived from the tendinous origin, which attached to the anterior surface of the lumbar vertebra and intervertebral disc. The upper margin of the origin was at the one third of the second lumbar vertebra in both sides. The lower margin of the right and left tendons extend to lower one third and upper one third of the third lumbar vertebra, respectively. In 22 cases (73.3%) out of 30 specimens, some muscular bundles arose from the right crus with the collagenous sheath. They ran across the ventral aspect of the aortic hiatus and bounded the esophageal hiatus at the left side. The muscular fibers, which bound the esophageal hiatus at the right and left, are innervated by ipsilateral phrenic nerve. In four cases, the “Hilfsmuskel” after Treitz was observed. It arose from the connective tissue around the coeliac artery.     

The effect of afterload on the cardiodepressor reflex response to coronary artery occlusion in dogs

The acute hemodynamic responses to anterior and posterior wall ischemia were examined at different afterloads in 30 open-chest anaesthetized dogs. Regional and global left ventricular responses to acute ischemia were also measured before and following bilateral cervical vagotomy in 18 dogs. As the preocclusion afterload (mean aortic pressure) was progressively raised with intravenous methoxamine, a significant decrease in stroke volume occurred following circumflex artery occlusion, whereas no change in stroke volume occurred following occlusion of the left anterior descending artery. Bilateral cervical vagotomy completely inhibited the decrease in stroke volume during circumflex occlusion at high afterload. Vagotomy had no effect on the hemodynamic response to acute anterior wall ischemia. Reversible cold vagal block in paced hearts at high afterload unmasked compensatory inotropy in the nonischemic anterior myocardial segment during circumflex occlusion. Restoring vagal tone by rewarming attenuated the fractional shortening of the nonischemic segment. The results indicate that a relationship exists between myocardial wall tension and reflex cardioinhibition during acute posterior wall but not anterior wall ischemia in dogs.     

Age-related characteristics of the distribution and attachment of chordae tendineae to the valves of the human heart

In 50 cardiac preparations of persons of various age (children, teenagers, adolescents, persons of mature and elderly age) distribution of various branches of the tendinous chordae (basic, marginal, commissural, rough zone) and level of their fixation to the ventricular surface of the right and left cusps of the atrioventricular valves have been studied. The tendinous chordae in direction from the apex of the papillary muscles towards the cusps of the atrioventricular valves are divided into the branches of the 2d--9th orders. Total quantity increase of the tendinous chordae is noted in the mature age, especially those of the 1st order in the left ventricle, and their decrease in the elderly age with an increase of the chordae of the 4th, 5th and 6th orders. Single chordae of the 8th and 9th orders can be found in elderly persons. Certain age specificities are revealed in fixation of various tendinous chordae to the cusps of the atrioventricular valves; they are surely connected with functional peculiarities of their different zones, that ensure air-tightness of the atrioventricular openings. There are quantitative differences of the tendinous chordae, fixed to certain cusps of the left (anterior) and right (anterior, posterior) atrioventricular valves; this is evidently connected with the role of the cusps mentioned in the mechanism of the valves closing.     

A very rare image in cardiology: posterolateral artery myocardial bridge

Muscle overlying of an epicardial coronary artery is termed a myocardial bridge. The frequency of myocardial bridging reported in angiographic studies varies from 0.5 to 16%.1 Myocardial bridging is usually confined to the left anterior descending coronary artery. A myocardial bridge of the branches of the right coronary artery is very rare.     

The coeloms in a late brachiolaria larva of the asterinid sea star Parvulastra exigua: deriving an asteroid coelomic model

Morris, V.B., Selvakumaraswamy, P., Whan, R., and Byrne, M. 2011. The coeloms in a late brachiolaria larva of the asterinid sea star Parvulastra exigua: deriving an asteroid coelomic model. —Acta Zoologica (Stockholm) 92 : 266–275. The coeloms and their interconnexions in a late pre‐metamorphic brachiolaria larva of a sea star are described from the series of images in the frontal, transverse and sagittal planes obtained by confocal laser scanning microscopy. A larval, brachial coelom connects with the coeloms of the adult rudiment that lie posteriorly. The connexion is through the anterior coelom, which lies over the head of the archenteron, to the right anterior coelom and then to the left posterior coelom through the ventral horn of the left posterior coelom. The right posterior coelom is a separate coelom. The hydrocoele is on the larval left side separated from other coeloms except for a connexion to the anterior coelom. On the larval right side, the anterior coelom and right anterior coelom connect with the pore canal that opens to the exterior at the hydropore. From these coeloms, we derived an asteroid coelomic model comprising the larval left and right coeloms linked over the head of the archenteron by a common anterior coelom. The asymmetry of the hydrocoele and the left posterior coelom on the left side linked through the common anterior coelom to the right side, with the external opening, translates into the oral and aboral coeloms of the adult stage. The coelomic model has application in the search for morphological homology between the echinoderm classes and the deuterostome phyla.     

Anatomic features of postmortem experimental ruptures of the human heart

Comparison of postmortem performed experimental cardiac ruptures with post-infarction lesions reveals uniformity of their localization. The ruptures are found to occur at places of a sharp change in the relief of the cardiac internal surface. These areas should be considered as concentrators of strain, promoting cardiac ruptures. In the left ventricle six concentrators of strain are revealed. They are: the place where the anterior part of the interventricular septum passes into the anterior wall of the left ventricle, the right edge of the papillary muscle, the left edge of the anterior papillary muscle, the left edge of the posterior papillary muscle, the right edge of the posterior papillary muscle, the place where the posterior part of the interventricular septum passes into the posterior wall of the left ventricle. Frequency of the experimental ruptures of the interventricular septum, under loading of the left ventricle, is demonstrated to depend on pressure in the right cardiac part.     

The Continuity of Right and Left Ventricular Myocardial Sinusoidal Spaces and its Relation to Right Ventricular Implants

Evidence is presented which indicates that blood leaving side branches of an internal mammary artery implanted into the anterior wall of the right ventricle flows from the tunnel in which it lies through myocardial sinusoidal spaces of the anterior right ventricular wall across the midline to fill corresponding spaces in the anterior wall of the left ventricle and thence is carried to the left coronary sinus. The myocardial sinusoidal spaces of right and left ventricles have been well outlined, using injections of polyvinyl acetate and the technique of digestion casts. We have been able to show that there is no barrier between the myocardial sinusoids of the right circulation and those related to the anterior descending branch of the left coronary artery. In structure, these myocardial sinusoidal spaces are quite different from the intramyocardial coronary arteriolar zones which, in 93% of human hearts, are separated from one another without collateral communication.The continuity of the right and left ventricular myocardial sinusoids explains why implantation of a right internal mammary artery into the anterior wall of the right ventricle combined with a corresponding left implant, epicardiectomy and free omental graft, has been so effective in our hands in the treatment of far-advanced human coronary artery insufficiency.     

Variations in coronary artery anatomy: Normal versus abnormal

We offer a comprehensive classification of coronary artery anomalies, together with angiographic examples of each entity. Minimal requirements for normality include the following criteria: (1) the dual aortic origin is from right and left coronary ostia; (2) the course of the right coronary artery follows the right atrioventricular groove; (3) the course of the left coronary artery follows the left atrioventricular groove and anterior interventricular groove; (4) the posterior descending branch originates from either the right or left coronary artery; (5) the major coronary branches flow epicardially; and (6) the coronary arteries terminate at the myocardial capillary level. This conception of "normal" coronary arteries has determined the classification of abnormalities presented here. Early and correct diagnosis of anomalies that may compromise the myocardial blood supply is stressed, and possible surgical solutions are offered. Selective coronary angiography is the technique of choice for precise visualization of the coronary artery system.     

AV blocking due to asynchronous vagal stimulation in rats

The parasympathetic nervous system innervates the heart through two cervical vagal branches. The right vagal branch mainly influences the heart rate by the modulation of the rhythmogenesis of the sinoatrial node. The left branch predominantly influences the conduction properties of the atrioventricular (AV) node. We investigated the effect of asynchronous stimulation by the vagal nerves on the occurrence of irregularities in heart rate. In rats, the vagal nerves were isolated and cut. Different vagal stimulation patterns (continuous, pulsed) were applied. The heart was beating spontaneously under continuous vagal stimulation. In case of pulsed vagal stimulation, the atria were paced at different rates. Asynchronicity was induced by delaying the right stimulus with respect to the left stimulus (early right) or the left stimulus with respect to the right stimulus (early left). The value of the fraction of deviated R-R or P-Q intervals in the distribution in the histogram was used to characterize irregularities during a stimulation protocol (duration in case of continuous stimulation: 20 s; pulsed stimulation: 120 s). Under both stimulation patterns (continuous or pulsed), we found that early left vagal stimulation introduced a much larger fraction of deviated intervals in the R-R or P-Q histogram (in R-R: 29.1 +/- 4.9%; in P-Q: 12.90 +/- 1.95%) than early right vagal stimulation (in R-R: 7.4 +/- 2.0%; in P-Q: 1. 05 +/- 0.50%) or synchronous stimulation (in R-R: 8.2 +/- 3.6%; in P-Q: 2.15 +/- 0.75%). We conclude that early stimulation by the left vagal nerve can introduce irregularities in heart rate, mainly due to different degrees of AV nodal blockade.     

Asymmetric limb malformations in a new transgene insertional mutant,footless

Six to eight copies of a transgene integrated into mouse chromosome 15 resulting in a new transgene insertional mutant, Footless, presenting with malformations of the limbs, kidney, and soft palate. Homozygotes possess a unique asymmetric pattern of limb truncations. Posterior structures from the autopod and zeugopod of the hindlimbs are missing with left usually more severely affected than right. In contrast, anterior structures are missing from the right forelimbs. The left forelimb is usually normal except for the absence of the distal telephalanges and nails. These structures are absent on all formed digits. In situ hybridization assays examined the expression of Shh, dHand, Msx2, Fgf8, En1, and Lmx1b in mutant limb buds and indicated normal establishment of the anterior/posterior and dorsal/ventral axes of the developing limbs. However, dysmorphology of the apical ectodermal ridge was observed in the mutant limb buds.