摘要:

AbstractSpecimens of mouse and rat cerebral cortex, fixed by immersion in osmium tetroxide and by perfusion with formalin‐osmium tetroxide were prepared for electron microscopy. The extracellular compartment, consisting of interendothelial cell spaces, capillary basement membranes and extracellular spaces between adjacent elements of neuropil, formed a morphological continuum with capillary lumina. A delicately fibrillar, extracellular matrix characterized the basement membranes and extracellular spaces of the neuropil. Desmosome‐like junctional complexes occurred between endothelial cells and between adjacent neuroglial cells.It is suggested that in the cerebral cortex molecular species from blood which pass through the basement membranes are further distributed in the cytoplasm of astrocytes. Astrocytic cytoplasm appears, then, to have assumed the histophysiological function of the connective tissue ground substance in other parts of the body. The relative constancy of the extracellular compartment as determined physiologically may relate to electro‐osmotic phen

ISSN:0003-276X    

DOI:10.1002/ar.1091520202

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

年代:1965

数据来源: WILEY

摘要:

AbstractIn human ribs the per cents of four kinds of bone surfaces (i.e., periosteal, haversian canal, cortical‐endosteal, and trabecular‐endosteal) that showed histological evidence of remodeling were measured. At each surface, (1) formative, (2) resorptive, and (3) neither form of remodeling activity was measured. The measurements were done at 350 X with the light microscope and a Zeiss integrating eyepiece II, on mineralized cross sections.The study showed that trabecular‐endosteal and cortical‐endosteal surfaces are approximately equivalent with respect to amount and type of remodeling activity per unit area at any given age. The periosteal surface showed little, and the haversian canal surface considerable, age dependent changes in amount of remodeling.Considerable variability existed within the age groups studied. An overall 16.8% of all surfaces showed histological evidence of bone formation, and 16.9% of bone res

ISSN:0003-276X    

DOI:10.1002/ar.1091520203

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe present work provides some quantitative evidence for the view that the inability of the lizard's limb to regenerate is due to an insufficiency of nerve fibers. The number of fibers per unit area of the amputation surface of the lizard's forelimb is approximately one‐half that reported for the limb of the salamander, capable of regeneration. It is known that when the number of fibers in the salamander's limb is reduced to about half its normal value, regeneration does not occur in about 50% of the animals. The possibility is also discussed that the lizard's limb, in addition to being less innervated than that of the salamander, is also more refractory in its growth response to the nerve. Finally, the comparative poverty of innervation of the lizard's limb relative to that of the salamander suggests that the evolutionary trend in the vertebrate series toward elaboration of central nervous mechanisms was accompanied by a decline in richness of peripheral innervatio

ISSN:0003-276X    

DOI:10.1002/ar.1091520204

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

年代:1965

数据来源: WILEY

摘要:

AbstractAn electron microscopic study of serial and/or closely spaced step sections of the murine glomerular mesangium is reported. Photomicrographs were obtained from sections which extended through mesangial cells from one side to the other. These cells are separated from the capillary by matrix as well as overlying endothelial cells and from the epithelium by matrix and basement membrane.The observations clearly demonstrate the presence of a “third” type of cell within the murine mesangium which is separate and distinct from endothelium and epithel

ISSN:0003-276X    

DOI:10.1002/ar.1091520205

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

年代:1965

数据来源: WILEY

摘要:

AbstractA study of the dural blood supply in 20 specimens by dissection, corrosion preparations and cleared specimens indicates that the dural arteries are similar to those of man yet significant differences were noted. The anterior cranial fossa is supplied by small twigs which spread through the dura of the anterior cranial fossa floor. The larger branch, the anterior meningeal artery, perforates the lateral orbital wall and supplies the lateral wall of anterior and middle cranial fossae. The middle meningeal artery, of the maxillary artery, divides into two branches in the floor of the middle fossa. The anterior or frontal branch always anastomoses with the anterior meningeal artery. Sometimes it also continues upward to the lateral wall of the middle fossa to supply it. The posterior middle meningeal branch passes backward to supply the parietal area. The posterior meningeal artery, of the occipital artery, enters the skull near the beginning of the sigmoid sinus and follows the general course of the lambdoidal suture.

ISSN:0003-276X    

DOI:10.1002/ar.1091520206

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

年代:1965

数据来源: WILEY

摘要:

AbstractThree negro cadavers examined during routine dissection showed remnants of the axis artery acting as important adult arterial routes through the lower extremity. In two of the three cases, the anomalous condition involved persistent ischiatic portions of the axis artery continued into the genicular region as the popliteal artery. In these cases, the function of the much reduced femoral artery was assumed by an over‐developed profunda femoris artery which, with its perforating branches, then entered the persistent ischiatic artery to give rise to the popliteal.In one of these cases, the infragenicular circulatory pattern was completely typical.In two of the three cases, one of which is included above, the anomalous condition of the axis artery involved the infragenicular circulatory pattern. In these, two anomalous conditions were obvious: (1) the peroneal artery rather than the anterior tibial, which was incomplete distally, carried the blood supply to the dorsalis pedis artery, and (2) the peroneal artery, by virtue of its position relative to the tibialis posterior muscle, represented the old interosseous part of the axis artery distal to the ramus communicans medius rather than the more recently developed superficial peroneal artery.The sequence of embryonic development of the arterial supply of the lower extremity is presented along with comments as to the cause and time of origin of the anomalous conditions presented herei

ISSN:0003-276X    

DOI:10.1002/ar.1091520207

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe innervation of extra‐ocular muscles of albino mice, aged 1, 10, 20, 30 annd 120 days, was studied in serial sections cut in the three main planes. Some orbits were fixed in Bouin's and others were fixed in a mixture of: 5% potassium dichromate, 5% mercuric chloride and 5% potassium chromate. All sections were stained with Holmes' silver stain. The following nerve endings were described:(a) Preterminal nerve fibers parallel to the muscle fibers end in 1–3 motor endplates in several muscle fibers and others form several en grappe end‐plates on one muscle fiber. (b) The muscles are rich in muscle spindles which have very thin capsules. Two spindles may lie side by side. (c) One or more nerve fibers form spirals around muscle fibers.Multipolar nerve cells were found:(a) Within the sclera, (b) Within the short ciliary nerves, (c) A complete ganglion formed of 20 cells was found along the inferior division of the oculomotor nerve.Unipolar nerve cells were seen along the nasociliary nerve. Harder's gland was innervated by a peri‐acinar plexus which sent nerve fibers between the cells as nerve endings. The significance of the findings was di

ISSN:0003-276X    

DOI:10.1002/ar.1091520208

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

年代:1965

数据来源: WILEY

摘要:

AbstractThis study was undertaken to test the hypothesis that the temporal fascia lends significant aid to the zygomatic arch in resisting the tensions of the m. masseter. It consisted of the unilateral removal of the fascia in two adult Cebus monkeys from its attachment on the superior and lateral surfaces of the arch, which were then covered with a plate of 24K 50 gauge gold to prevent re‐attachment. Frontal and lateral cephalometric x‐rays were taken and the animals were given three i.v. injections of lead acetate (4 mg/kg body weight) at two‐week intervals beginning at time of operation and sacrificed two weeks after the last. The arches were removed close to their attachments and prepared for histological study according to modified technique of Scheiman‐Tagger and Brodie ('64).Frontal sections through the right and left arches revealed striking differences between them. The operated side measured approximately 25% less mediolaterally and 16% greater superoinferiorly than the unoperated side. Oriented frontal and basal head x‐rays at 5 ft target distance revealed the operated side to be 4 mm lower and 2 mm closer to the midline. The lead lines showed the extensive internal as well as external remodeling that had taken place. Deposition and resorption areas indicated the drifting of marrow spaces and of the zygomaticotemporal suture in the direction of the unopposed pull of the m.

ISSN:0003-276X    

DOI:10.1002/ar.1091520209

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe external morphology of the erect glans penis was studied and compared to that of the nonerect organ. Morphological changes that occur with tumescence and detumescence were also reported. Some distinct parts of the erect pars longa glandis which are not distinguished in classical nomenclature are described and labeled. These structures are the urethral process, corona glandis and collum glandis. These distinct morphological areas coincide with areas which seem to be functionally distinct in both the erect and nonerect glans penis. The implications that these observations may have for considerations of comparative anatomy of the external male genitalia are discussed.

ISSN:0003-276X    

DOI:10.1002/ar.1091520210

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

年代:1965

数据来源: WILEY

摘要:

AbstractIn DBA mice, 12–16 months of age, receiving an adequate commercial diet the incidence of ventricular myocardial necrosis and calcification was 48% and that of pericardial calcification was 12%. Atrial thrombosis did not occur. Young adult mice of the same strain were fed a high‐fat (28% lard), low‐protein (8% casein) diet, with and without lipotropic supplement of betaine, for 48 weeks. The incidence of ventricular myocardial necrosis and calcification increased significantly over the spontaneous level with the greatest frequency (95%) occurring in the betaine‐supplemented group. Pericardial calcification also increased with the highest incidence (100%) in the non‐supplemented animals. Dietary induced atrial thrombosis reached lethal dimensions (80%) for most animals in the betaine‐supplemented group within 12 weeks. The non‐supplemented animals had less atrial thrombosis (50%) and greater longevity. Frequency and types of lesions observed were similar to those which occur in other strains of mice fed the same diet. The genetic susceptibility to spontaneous cardiac lesions did not appear to predispose the DBA mice to a greater sensitivity to dietary induced lesions, but may have contributed to the calcification which characterized the lesions. Dietary betaine seemed to influence significantly the production of a higher incidence of c

ISSN:0003-276X    

DOI:10.1002/ar.1091520211

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

年代:1965

数据来源: WILEY