Functional and developmental morphology最新文献

We have studied the development of sternum in man. Complete microscopic series of sections through thorax of human embryos and fetuses from the second and third months of gestation served as the research material. Preparations were stained by Alcian blue and Mayer's haematoxyline, counterstained by eosine. We also had a set of macroscopic preparations of sterna and adjacent parts of ribs from fetuses of the fifth and sixth months of gestation. These specimens were stained by Alcian blue and by Alizarine and subsequently cleared by glycerine method. We have found that sternum develops by a fusion of sternal bars. Sternal bars develop from anterior bent parts of ribs, lying one over another like tiles. The newly formed sternum has different proportions in comparison to its definitive state. In all the cases its manubrium is wider and bigger, its xiphoid process is longer, in almost all the cases doubled or at least bifurcated. The sternocostal junctions are provided with interzones with the exception of the first rib. Its primordium continues into sternum without any border. Clavicle is connected with sternal anlage without any visible border and this interzone quickly develops as the primordia of the sternoclavicular articulation and the disc. In the medial part, there is a cartilaginous model which ossifies very early--as the first bone of the body. In young embryos from the end of the second month of gestation the clavicle and sternum show very different structures. Ossification of the sternum begins in the fifth month by developing a large number of very small centers of ossification which are not yet detectable by X-ray or CT.(ABSTRACT TRUNCATED AT 250 WORDS)

We studied the development of the epipharynx in normal human ontogeny comparing findings in fetuses with severe CNS malformations with those of normal fetuses of a comparable stage of development. Normally, the epipharynx forms a tube and bends at a right angle, whereas, in the fetuses with CNS malformations, the epipharynx develops as a balloon-like form of slightly triangular shape. In hydrocephaly, it formed a narrow tube that was nearly vertical. We concluded that the early formation of the epipharynx is influenced by the separation of the notochord and the formation of the basicranium, by ascendant processes during vertebrogenesis, and by the neotenic development of the maxillomandibular complex.

The internal male reproductive organs of Tramea virginia consist of a pair of testes, a pair of vasa deferentia (which in adult modify distally into seminal vesicles), a median sperm sac and a short ejaculatory duct. The development of the genital tract occurs in the ultimate nymph. Each testicular lobule contains the gametes showing collectively only a single stage of spermatogenesis. The process of spermatogenesis is vigorous in the ultimate nymph and, therefore, the newly emerged imago contains active spermatozoa in its testicular lobules. Spermatophores are not observed in the genital tract of the adults.

Cell structure of the hypothalamic preoptic region in goose has been studied and topographical relations of the following nuclei (n.) are shown: n. preopticus rostralis, n. preopticus periventricularis, n. preopticus medialis, n. supraopticus, n. suprachiasmaticus, n. preopticus lateralis, n. magnocellularis preopticus, n. rostralis hypothalami, n. supraopticus caudalis, n. decussationis supraopticae dorsalis and n. decussationis supraopticae ventralis. The nomenclature given in Nomina anatomica avium (Breazile 1979) has been used, as for as possible.

Samples from 16 endomyocardial biopsies obtained from three patients, provided cyclosporine immunosuppression, at 3-6 years since heart transplantation were examined in light and electron microscopy. In light microscopy, the endomyocardial biopsies of the patients examined within that period were free of signs of acute rejection, practically within the normal range. In electron microscopy, intercalated discs, glycogen, mitochondria, myofibrils, lipid droplets, lipofuscin granules, sarcoplasmic reticulum in myocytes and interstitial space were examined. Results of ultrastructural studies indicate that alteration of myocytes increases with time, the longer the interval since heart transplantation, the more myocytes show changes in the above structures. Irreversible changes and myelin bodies were found sporadically in myocytes that were in normal state.

The structural differentiation of the Müllerian ducts of both sexes was studied in rat fetuses from 15 to 21 days of gestation. Differences between the male and female Müllerian ducts were observed from the 17th day onward. The epithelium of male Müllerian duct lost its regular arrangement, the increased lysosomal activity and disintegration of some cells was found. The involution of the male duct was accompanied by the condensation of the surrounding mesenchyme with the participation of macrophages. The female Müllerian duct was lined with simple columnar epithelium; its pattern remained indifferent until birth. The apical migration of centrioles and solitary cilia formation belonged to the typical findings from the 18th day. Neither ciliated cells nor multiple centriole replication were observed in oviductal segment of Müllerian duct.

Three-dimensional organization of diaphragmatic lymphatics in five fetuses was studied by the lymphatic casts of scanning electron microscope. A new resin consisting of piperylene, acrylic ester and styrene was used instead of Mercox. The diaphragmatic lymphatics formed rich networks in the muscular portion. There were two layers of lymphatic networks, i.e. the submesothelial network and the deeper network and only one layer in the tendinous portion of the diaphragm. The lymphatic networks were more dense in the tendinous portion than these in the muscular portion. The lymphatics were mainly composed of main lymphatic vessels and anastomosing side branches. The side branches often communicated the submesothelial network with the deeper network in the muscular portion. The main lymphatics were connected at regular intervals by way of transverse side branches in the tendinous portion. Numerous constrictions and notches showing the presence of lymphatic valves were often found on the cast surface of the main lymphatic vessels and the side branches. The lymphatics extended as far as the terminal branches, i.e. the lymphatic lacunae recognized as broad, flattened and blind-ended. In the present study, three-dimensional organization of human diaphragmatic lymphatics was for the first time described. It was suggested that the passageway of the lymph flow out of the peritoneal cavity may be explained. From the peritoneal stomata, the lymph of the peritoneal cavity flowed into the channels under the peritoneum, then into the lymphatic lacunae and finally into the lymphatic networks under the diaphragmatic pleura.

In Garra gotyla and Pseudecheneis sulcatus, the interrenal and chromaffin tissues represent homologues of the adrenal cortex and medulla, respectively, and are confined to the largely lymphoid head kidneys in a bilaterally symmetrical topographical pattern. Together they form a collar round the postcardinal vein, with a thickness of 300 microns in Garra gotyla and 150 microns in Pseudecheneis sulcatus. Distributionally, the interrenal tissue conforms to Nandi's type III and type I and the chromaffin tissue to type V and type III in Garra gotyla and Pseudecheneis sulcatus, respectively. The interrenal cells in these species are polygonal, cuboidal or columnar, and are filled with coarse basophilic cytoplasm. The chromaffin cells form syncytial patches and have sparsely granular cytoplasm.