摘要:

AbstractTwo cases are described in which enormous bloodless peritoneal sacs occupy the abdominal cavity and enclose the small intestines. Back of the sac the colic arteries and veins are in normal anatomical position. The inferior mesenteric vein has been converted into a fibrous cord with resulting reversal of venous return from the hindgut into the hypogastric vein. These cases conform to Papez's concept of the so‐called paraduodenal hernia: the peritoneal sac is derived from the embryonic umbilical peritoneal cavity. The authors suggest that most, if not all large intraperitoneal sacs, the so‐called paraduodenal hernias, are derived from the embryonic umbilical peritoneal diverticu

ISSN:0003-276X    

DOI:10.1002/ar.1091550202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractDistribution of cholinesterase within the sinus node, AV node and His bundle of the human heart was studied utilizing acetylthiocholine as the substrate. Cholinesterase is present in large amounts in the conduction system tissue, much smaller amounts in right atrial myocardium and was not observed in ventricular myocardium. The sinus node artery was devoid of cholinesterase, as was the sarcolemma and nucleus of cells in the conduction system. Cholinergic nerve endings stained the most heavily of all tissue studied and were more numerous in the sinus node than the AV node. Stellate‐shaped cells previously suggested to be the pace‐making site in the sinus node were found to contain abundant cholinesterase. Fibers in the AV nodal bypass tract, which lies between the AV node and right atrial endocardium, also contain cholinesterase. Within individual cells of the sinus node cholinesterase could be identified within myofibrils, with periodic absence in the linear staining most likely corresponding to the Z bands. Other organelles within the cells also contained cholinesterase, but their precise definition was impossible with the present technics. Possible functional significance of these histochemical observations were discus

ISSN:0003-276X    

DOI:10.1002/ar.1091550203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractThe objective was to determine on what day of development the vagal complex i.e., dorsal motor nucleus in the floor of the fourth ventricle, vagus nerve and post synaptic neuron assumes functional control of the heart rate in the chick embryo. Adapting a technique used by Armstrong ('35) for the Fundulus embryo, 0.003 ml of Tyrode solution containing 0.03 μg of acetylcholine was injected into the fourth ventricles of 16 chick embryos at four days of age, 25 at five and 15 at six days of age. Heart rates were taken before and after injection.Analyzed statistically no significant changes in heart rate occurred following injection of acetylcholine into four day embryos but at five days a significant average drop from 106 to 95 beats per minute occurred. The same was true in six‐day‐old embryos where the average drop in rate was from 108 before to 84 after injection. As proof that the acetylcholine injected into the brain ventricle acted by stimulating the vagal mechanism and not by diffusing into cerebral blood vessels and being carried to the heart we found that corresponding amounts of acetylcholine injected into omphalomesenteric veins had no significant effect on heart rate. Also 0.003 ml of plain Tyrode solution injected into the fourth ventricle elicited no significant response. These observations justify the conclusion that the vagal pathway to the heart becomes functional between five and six days of development in the chick em

ISSN:0003-276X    

DOI:10.1002/ar.1091550204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractNeuromelanin pigment of the substantia nigra and locus coeruleus from nine human autopsy cases and from four rhesus monkeys was studied. Melanin and lipofuscin pigments from other anatomical sites were also observed for the purpose of comparison with the substantia nigra‐locus coeruleus pigment. Ultrastructurally, the neuromelanin pigment granule was composed of three distinct components. The first was a finely granular, medium dense matrix which occasionally had linear configurations very similar to those of neuronal lipofuscin granules from human cerebral cortex. The second component was a very dense, coarsely granular material which appeared to to be deposited on the finely granular matrix. This very dense component was apparently the reducing part of the neuromelanin granule, as it was the site of localization of silver deposits in formalin‐fixed tissue which had been stained with diamine silver prior to post‐osmication and examination in the electron microscope. No evidence of silver reduction was noted in lipofuscin pigment. The third component of the neuromelanin granule was a lipid globule which was not preserved in glutaraldehyde or formol‐permanganate fixed tissue. A lipid globule was not observed in melanin granules from the skin, eye, or pi

ISSN:0003-276X    

DOI:10.1002/ar.1091550205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractThree specimens from Balaenopteran whales have been available for study: a 20 mm embryo, a fetus 57 inches long and the ampulla duodeni of a 47‐foot adult. By reconstruction, dissections and histological preparations, it has been possible to show that the extrahepatic portion of the bile duct is really an elongated hepato‐pancreatic duct receiving ductules draining both rostral and caudal pancreatic lobes. After coursing through the pancreas, this duct pierces the intestinal muscle at the beginning of the pars descendens duodeni, then runs through the whole length of the longitudinal fold before emptying at the bottom of the pars descendens. In the adult, maceration methods have demonstrated that there is no vestige at all of a sphincter of Oddi. Presumably, this is a consequence of the absence of the gall bladder. Contrary to statements in the literature, a complete foramen epiploicum, vestibule and lesser peritoneal sac could be demonstrated as well as a long infracardiac bursa. Most interesting is the presence of a sizable valve in the portal vein at the point where it enters the li

ISSN:0003-276X    

DOI:10.1002/ar.1091550206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractThe iridial constrictor pupillae muscle ofAlligator mississippiensisis found to consist of admixed smooth, myoblast‐like, and striated muscle cells. Melanophores, bundles of collagen fibrils, nerve cell processes, and smooth muscle cells, which contain melanin granules, are found scattered in the constrictor pupillae muscle. Protoplasmic bridges are present between myoblast‐like cells and between myoblast‐like and striated muscle cells. Myoblast‐like cells contain agranular reticulum, free ribosomes and randomly scattered, or longitudinally oriented filaments of two sizes (50–100 A and 200–250 A). Free ribosomes are found individually and in clusters of 5 to 10. The agranular reticulum is found as anastomosing tubule‐shaped and cisternal elements. The striated muscle fibers consist of myofibrillae and a poorly organized sarcoplasmic reticulum and T system, such that triads and diads are not precisely ordered, but randomly scattered throughout the muscle fiber.This data is discussed in terms of the differentiation and function of striated muscle. On the basis of the disposition of triads and dyads it is concluded that the striated muscle of the constrictor pupillae muscle ofAlligator mississippiensisis a slow‐acting rather than fas

ISSN:0003-276X    

DOI:10.1002/ar.1091550207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractStructural changes occurring in the submandibular glands of mice during pregnancy were studied. The submandibular glands of 12 mice were examined immediately post‐partum, and those of a further 12 six weeks post‐partum. They were compared with glands of virgin female and young adult male mice. The mean weight of the glands immediately after pregnancy was 75% greater than that of the glands of virgin female mice of the same age.In both hematoxylin and eosin, and Mallory‐Heidenhain stained sections there was evidence of masculinization of the submandibular glands during pregnancy. The percentage of convoluted granular tubules in the glands increased; as did also the diameter of the tubules. The characteristic appearance of the constituent cells of the tubules in the gland of the virgin female, with basal striations and centrally located nuclei was converted to that seen typically in the young adult male, where the cells have basally located nuclei, and an abundance of apical granules but no basal striations.Regression in both the weight and microscopical appearance of the glands to the non‐pregnant condition occurred within the six weeks following pregnancy.The apparent masculinization of the submandibular glands during pregnancy is thought to be an expression of the complementary endocrine factors acting at th

ISSN:0003-276X    

DOI:10.1002/ar.1091550208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractPairs of fine wire electrodes were inserted by means of hypodermic needles 1 cm apart into the semispinalis capitis, semispinalis cervicis, spinalis, longissimus, iliocostalis lumborum, main mass of the erector spinae between the ilium and the twelfth rib, the multifidus and glutenus maximus of 20 young men and women.Each pair of electrodes was connected to an EMG integrator coupler in an 8‐channel recorder. Because the integrated electromyogram is displayed as a deviation from the baseline proportional to the strength of the muscle contraction, it was possible to appraise the relative contributions made by different muscles to any given movement or exercise. By this method simultaneous recordings were made from the muscles while the subjects flexed, extended, hyperextended, abducted and adducted the trunk from the orthograde position; walked on a treadmill, lifted weights; and performed certain exercises recommended by the President's Council on Adult Physical Fitness. Many exercises were compared, and the best ones were selected on the basis of the strength of the contractions they produced. The best exercises for strengthening the deep muscles of the back were those that involved hyperextension of the back from the prone position.Contrary to current opinion, the erector spinae is not active during abduction or adduction of the trunk from the orthograde position if the body is maintained in the frontal plane.The integrated electromyogram is an excellent tool for the evaluation of exercise

ISSN:0003-276X    

DOI:10.1002/ar.1091550209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractElectron micrographs from this study demonstrate several stages in the formation of the nuclear cap and acrosome by the Golgi system. Formation of small vesicles from Golgi membranes, coalescence of these vesicles into the nuclear cap with concomitant fusion of contained granules to form the acrosome, is confirmed. Mitchondria, which at low magnifications appear to be “empty,” are shown by high magnification to contain dilated intracristal spaces. In many cases cristae are arranged parallel to the mitochondrial surface.In later spermiogenesis, appearance of the caudal sheath or manchette, proximal centriole, and terminal annulus (“ring centriole”) precede formation of the middlepiece and flagellum. The presence of a series of parallel “annulated” membranes has been described. The exact nature of these membranes, which appear to connect with the cisternae of the endoplasmic reticulum, remains to be i

ISSN:0003-276X    

DOI:10.1002/ar.1091550210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractThe histological structure of the squamo‐columnar junction of the cervix uteri of mice was studied during the estrous cycle, pregnancy, lactation, and in ovariectomized and estrogen‐stimulated animals. In the absence of endogenous or exogenous estrogen, there was no clear demarcation between the squamous and the columnar epithelium; the epithelium in the zone of transition resembled types previously described in the human cervix that have been regarded as evidence of a metaplasia of columnar to stratified epithelium. However, in the mouse, estrogen stimulation caused the disappearance of the transitional zone so that an abrupt junction resulted. It was concluded that the type of junction is controlled by estrogen, and that the stratified epithelium of the transitional zone may differentiate to produce either keratinized cells or cells of uterine type at its surf

ISSN:0003-276X    

DOI:10.1002/ar.1091550211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY