The membranous part of the human interventricular cardiac septum.

The arrangement of collagen and elastic fibers of the membranous part of the interventricular septum (PMS) was studied in hearts from adult humans. Connective bundles formed a network of fairly independent tendons arranged in two layers. The tendinous bundles consisted essentially of type I collagen fibers while type III fibers were visible as a thin network with transversely and longitudinally oriented meshes around the muscle bundles. Cranial and caudal to the PMS were narrow and irregular bands of collagen fibers that apparently represented zones of low resistance to the high blood pressures acting from the left to the right heart chambers. The predominance of fiber bundles arranged in an approximately transverse direction with regard to the arterial cone axis suggests a resistance to enlargement resulting from high aortic blood pressure. Elastic fibers were observed in the transitional zone between the cardiac muscle and the PMS. They were continuous with elaunin fibers and these with oxytalan fibers closely intermingled with the narrow network of type I collagen fibers of the PMS. The successive transformation of elastic fibers, which were very numerous in the muscle-tendon transition, into elaunin and these into oxytalan fibers toward the central portions of the PMS suggests a functional sequence characterized by a high elasticity and consequent mobility of the transition region itself and by a progressive increase of resistance in this portion.

Dietary sodium intake and cardiac nerve cell hypertrophy in Wistar rats.

We determined the effect of dietary sodium intake (0.15 and 8% NaCl) on the cardiac neuron size of normotensive 3-week old Wistar rats. An increase in dietary sodium for 48 weeks induced an increase in neuronal size. The number of large neurons (larger than 500 microns 2) increased significantly (chi-square test) in rats ingesting 8% NaCl in their food. The rats presented hypertension (128 +/- 9 vs 134 +/- 16 mmHg; difference not significant, Student t-test) and a statistically significant increase in cardiac muscle mass (1.6 +/- 0.1 vs 2.0 +/- 0.2 mg/g of rat). We conclude that food sodium can significantly increase cardiac nerve cell size and this trophic response occurs concomitantly with an increase of cardiac muscle mass.

Dietary sodium intake and cardiac nerve cell hypertrophy in Wistar rats

We determined the effect of dietary sodium intake (0.15 and 8 per cent NACl) on the cardiac neuron size of normotensive 3-week old Wistar rats. An increase in dietary sodium for 48 weeks induced an increase in neuronal size. The number of large neurons (larger than 500 muM2) increased significantly (chi-square test) in rats ingesting 8 per cent NaCl in their food. The rats presented hypertension (128 ñ 9 vs 134 ñ 16 mmHg; difference not significant, Student t-test) and a statistically significant increase in cardiac muscle mass (1.6 ñ 0.1 vs 2.0 ñ 0.2 mg/g of rat). We conclude that food sodium can significantly increase cardiac nerve cell size and this trophic response occurs concomitantly with an increase of cardiac muscle mass.

"Sphincter" of the minor papilla of the human duodenum.

The arrangement of the smooth muscle and elastic and collagen fibers of the minor papilla of the human duodenum was studied on 53 duodenopancreatic specimens obtained from adults of both sexes. Methods included stereological analyses of gross anatomical specimens and thick and thin microscopic sections. The muscular and elastic fibers of the minor papilla have a unidirectional arrangement by which the contraction of its smooth muscular fibers causes opening of its orifice allowing the flow of the pancreatic juice into the duodenum. It is not a typical anatomical sphincter.

Light and electron microscopy of the human hepato-duodenal ligament: a morpho-functional study.

The morpho-functional relationships between the hepato-duodenal ligament and the superior part of the duodenum are analysed. Twenty-four specimens were removed during necropsies of adults and prepared according to various mesoscopic, microscopic, and ultramicroscopical methods, i.e., whole-mounts, membrane preparations, thick and thin histological sections, and polarized light, scanning, and transmission electron microscopy were employed. The hepato-duodenal ligament is formed by longitudinally elongated, type I collagen fiber bundles which are interlinked by more delicate bundles of type III collagen fibers. Longitudinally disposed elastic fibers are the principal component of the elastic fiber system of the ligament. These are in continuity with the elaunin and oxytalan fibers which are intermingled with the muscle cells of the vessels and duodenal wall, and fat cells of the ligament. Part of the muscle bundles of the external, longitudinal, muscle layer of the duodenum is anchored in the adventitial and subserosal collagen and elastic fiber framework of the organ while part inserts directly into the fibrous framework of the ligament. The fibrous system of the ligament is continuous with that of the subserosa and adventitia of the duodenum.

Scanning electron microscope study of the veins at the human esophago-gastric junction.

Cast of the mucosal and submucosal veins of the esophago-gastric junction were studied in five necropsy specimens by scanning electron microscopy to analyse some of the characteristics of their shape and surface. Two types of veins were described: 1) veins with circumscript, fusiform and/or ampullar bulges and relatively smooth surfaces; 2) veins with numerous, small bulges and blister-shaped micro-dilatations. The role of these features is considered in the formation of esophageal varices.

Myenteric neurons of the mouse small intestine. Morphometry and acetylcholinesterase activity.

1. The myenteric plexus of the small intestine of five C57BL/6J male 5-month-old mice was investigated in whole-mount preparations of the muscularis externa by Giemsa staining and by the acetylcholinesterase (AChE) histochemical technique. 2. The neuronal density was 20212 +/- 3038/cm2 (mean +/- SEM) in the duodenum, 21948 +/- 1488/cm2 in the jejunum, and 25048 +/- 2356/cm2 in the ileum. The difference in neuronal density between duodenum and ileum was statistically significant (P < 0.05). The total serosal surface area of the small intestine was about 30.80 +/- 2.90 cm2, and the total number of neurons was estimated at about 690,000. 3. The neuronal cell and nucleus profile areas ranged, respectively, from 23 to 325 microns 2 and from 6 to 95 microns 2 in the small intestine of the mice studied. There were no significant differences in any of the 3 regions in terms of average neuronal cell or nucleus profile areas. 4. For the histochemical demonstration of AChE, the "direct coloring" copper ferrocyanide method was used. AChE-positive nerve fibers were distributed in the myenteric plexus which was formed by a primary meshwork of relatively large nerve bundles and a secondary meshwork of finer nerve bundles. Most of the neurons of the plexus displayed AChE activity in the cytoplasm though the neurons presented different reaction intensities.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional anatomy of the retro- and suprahepatic portions of the human inferior vena cava and their main affluents.

The arrangement of muscle, collagen and elastic fibers was studied in the retro- and suprahepatic (subdiaphragmatic) portions of the inferior vena cava, the hepatic veins and their main affluents. Distinctive features of the longitudinal and transverse muscle bundles are described. In these portions of the vena cava, both bundle systems are clearly separate and any continuity was observed only at the entrances of the hepatic veins. A musculo-venulolymphatic complex was noted in spurs formed by the vascular junctions. The hepatic veins and their main affluents exhibit an elliptical contour in transverse section, which apparently results from cranial and caudal thickenings of the longitudinal muscle layer. Many of these bundles are in continuity with those of the transverse muscle layer. Terminal elastic tendons were rarely observed in connection with muscle fibers of the inferior vena cava and are not present in the hepatic veins and their main affluents. In terms of form and function, the relatively thin muscular layer has a dilating action on the hepatic venous system because of the external fixed insertion point of the muscle bundles. Such an arrangement and a "polar" disposition of the muscle bundles in the hepatic venous system may assists in "suction" of the blood toward the heart. A sphincteric control of the ostia by means of crossed muscular loops supported by venulo-lymphatic micropads is a possibility.

Ultrastructural aspects of and observations on the permeability of the rat mesentery to colloidal iron.

In works already published, it was made clear that many researches were interested in the absorption phenomena, permeability and structure of the visceral mesothelial tissue. Attention was concentrated on the mesentery and observations were made using the application of lanthanum nitrate and osmium-amine. The penetration of lanthanum nitrate is impeded by the basement membrane situated between the connective and mesothelial tissues. The heavy salt moves through and not between the mesothelial cells by passive diffusion. No reaction was observed in general with osmium-amine, with the exception of a few cases. In those instances, the osmium-amine reacted not only in the outer surface of the mesentery, but also penetrated with no visible reaction all the way to the connective tissue where it was detected in the elastic layer. In this paper, the colloidal iron was employed using different techniques, and depositions were detected in the surface of the mesentery, in the mesothelial cells and also in the connective tissue. A final conclusion that the permeability of different layers of tissues is of great variety and has a definite capacity for selectivity is suggested.

Identification of collagen, elastic, elaunin and oxytalan fibres in ganglia of the myenteric plexus of the human oesophagus.

The connective tissue associated with the myenteric plexus of the human oesophagus was studied by light and electron microscopy. Collagen fibres were identified by picrosirius staining with polarization microscopy and from their fine structural morphology. A capsule of connective tissue invests the ganglia while septa of connective tissue separate groups of ganglion neurons, surrounding each individual ganglion neuron and each nerve bundle. Collagen fibrils surround the ganglia, each ganglion neuron and each nerve bundle. The fibrils are disposed in various orientations forming networks. Elastic, elaunin and oxytalan fibres were identified by their staining characteristics and fine structural morphology. The bulk of the ganglion sheath consists of coarse elastic fibres and elaunin fibres. Elaunin and oxytalan fibres form the intraganglionic network. Oxytalan, elaunin and elastic fibres appear to be located in areas related to different stresses and deformation to which the ganglia of the myenteric plexus are exposed during the contraction of the esophageal wall. The ganglia of the myenteric plexus of the human oesophagus show structural organisation of the connective tissue component similar to that seen in sympathetic and parasympathetic ganglia.

An ultrastructural and morphometric study of pre- and post-hatching satellite cells in lumbar sensory ganglia of Gallus gallus domesticus L.

An electron microscopic study of satellite cells in the sensory lumbar ganglia from 12 pre- and post-hatching stages of Gallus gallus domesticus L., between the 5th and 120th d, was undertaken. A combined light and electron microscopic morphometric analysis was made in 10 and 18 d embryos and in 8, 35, 61, and 120 d post-hatching specimens. RER, SER, Golgi complex, mitochondria, free ribosomes, cell expansions, pinocytotic vesicles, subsurface cisternae and adhering, gap, and tight junctions are described from the different stages considered. Although a continuous increase in nuclear and cytoplasmic volumes is observed, there is a tendency towards a decrease in the cytoplasm/nucleus and nerve cell/satellite cell volume ratios.

Functional architecture of the splenic vein in the adult human.

The spatial arrangement of the muscular, elastic and collagenous fibers was examined in 20 splenic veins of adult humans. Histologic and panorganographic sections were stained by the following methods: azan, resorcinfuchsin (Weigert), Verhoeff-van Gieson's stain and Masson's trichrome. Unstained sections were examined under polarized light. The results show that the muscular and collagenous fibers of the splenic vein exhibit an elongated spiral arrangement with no polarization. The elastic fibers form a threedimensional network disposed predominantly in a longitudinal direction. Hemodynamics are discussed based on the spatial structure of the muscular, elastic and collagenous elements of the vein wall and its relationship with the circulatory functions of the spleen.

Functional anatomy of the tela submucosa of the valva ileocecalis in the adult man.

The collagen and elastic fibres of the tela submucosa and their relationships with the tunica muscularis in the human ileocecal valve were studied in 61 anatomic specimens of adult individuals, using meso- and microscopical technics. 2 fibrous components were described: one intrafascicular, which arises from the muscular bundles, and another, interfascicular, which coming from the connective intermuscular layer of the tunica muscularis, pass between the annular bundles toward the tela submucosa. In the tela of the terminal ileum these fibrous components form, like the muscular bundles of the annular layer, a "polar" system, which vanishes at the level of the "marginal sphincter" and in the cecocolic aspect of the ileal papilla. A system of muscular-elastic-collagen bundles is described in these 2 last portions, extending from the tunica muscularis toward the tela submucosa. 2 patterns of arrangements were observed in the tela submucosa: one lamellar, in the terminal ileum and part of the ileal papilla, and another areolar, in the apex and part of the cecocolic aspect of the papilla. A morphometric study was performed in order to estimate the distribution of fat cells in the tela submucosa of the ileocecal valve. It revealed a gradual increase of fat cells amount toward the apex and cecocolic aspect of the papilla ilealis. Some morphofunctional considerations are made, concerning the ileocecocolic junction control.

The elastic fibre system in the veins of the human lower oesophagus.

The elastic, elaunin and oxytalan fibres in the tunica mucosa and tela submucosa of veins of the human lower oesophagus were studied in 30 necropsy and biopsy specimens using appropriate histological and ultrastructural methodologies. Elaunin fibres predominate in the veins endowed with muscle cells. Scattered oxytalan and elastic fibres were also observed, the latter being more numerous at the vein periphery. No noteworthy fibre arrangement was encountered in veins lacking muscle cells. Those fibres disposed around the veins were considered to belong to the connective tissue of the tunica mucosa and tela submucosa in which they are embedded. The veins of the lower oesophagus seem to be of low elasticity, which may be related to a blockage mechanism described for the gastro-oesophageal blood stream in cases of portal hypertension.

Morphological aspects and observations about the permeability of the rat mesentery to the osmium-amine.

In a previous work we felt that many authors were interested in observing the permeability and structure of the mesentery employing many techniques and analysing the material from different points of view. Our collaboration, at that time, was limited to the study of the permeability of the mesentery to the lanthanum nitrate and we came to a final conclusion that the penetration of the heavy salt is impeded by the presence of a basement membrane, localized between the mesothelial and connective tissue layers and that it was continuous to the basal lamina, located between neighbouring mesothelial cells; we could then observe that the lanthanum traveled through the cytoplasm and not in between mesothelial cells. In this paper we analyze the behavior of the mesentery in relation to the osmium-amine and we compare it to the observations made in our previous work. Generally speaking, we were unable to observe any reaction in any of the structures of the mesentery, except for some special cases. In those not very common cases, employing special techniques, we came to the conclusion that the osmium-amine reacts in the periphery (outer surface) of the mesentery and also penetrates, sometimes with no visible reaction, all the way to the elastic layer, where a reaction can be detected.

Correlative scanning and transmission electron microscopic study on the ependymal surface of Cebus apella.

Topographical variations of the ependymal surface of the whole brain ventricular system of Cebus apella, a wild Brazilian species, were studied at the scanning electron microscope after CO2 critical point drying and carbon-gold coating. Certain selected areas were also studied at the transmission electron microscope, following standard technical procedures. We observed distinct patterns in the distribution of cilia, microvilli, other cell projections, and the so called supraependymal structures. Based on the morphological findings, functional considerations are made.

The architecture of the splenic artery in the adult man.

The spacial arrangement of the muscular, elastic and collagen fibers was examined in 27 splenic arteries (SA) of adults, 15 of these being males. There were realized, histologic and panorganographic sections, that received adequate staining according to their thickness, by one or most of the following methods: Azan, resorcin-fuchsin (Weigert), Verhoeff-Van Gieson, Sudan III or Masson trichome. Pellicle or total preparations were treated by alum carmine, Van Gieson, resorcin-fuchsin or nitric acid. Any sections and total preparations without staining were examined by polarized light. The finding shows a spiral disposition, without polarization, of the muscular and collagen bundles of the SA. The elastic fibers have different arrangements in the tunics of the SA. Support bundles are present in the proximal and distal extremities of the artery. The vessel dynamic is discussed in function of the spacial arrangement of the muscular, elastic and collagen elements, in relation to the support bundles and also the mechanic function of the spleen.

A nervous connection between the hepatic plexus and right atrium in man.

The authors studied 43 necropsy specimens from adult individuals by dissection under a stereomicroscope and by staining methods (Cajal-De Castro and Palmgren silver impregnations, Kl uver Barrera and Pal-Weigert for the myelinated fibers, and Van Gieson and Azan trichromic methods). They suggest the presence of a direct nervous connection between the hepatic plexus (celiac plexus) and the right atrium via the left branches of the hepatic artery and portal vein, venous ligament, left hepatic vein, and V. cava inferior, passing through the foramen for the V. cava. This connection is made by very fine nerves from the upper part of the venous ligament until the left atrium, which generally are only visible on the microscopic level.

Functional anatomy of the perivascular tissue in the adductor canal.

Lower limbs of human adults, males and females, were used for micro- and mesoscopic studies of the collagen-elastic arrangement of the tissue surrounding the femoral vessels on their course along the adductor canal. The vessels' sheaths and lamellae which join them to the canal walls, are formed by strong networks of collagen and elastic fibers, and the perivascular area is filled by thin lamellae of connective tissue, delimiting lobules of adipose tissue. The functional importance of this arrangement to the mechanic protection of the vessels during contraction of the muscles related to the vessels in the adductor canal is discussed.