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A S Maiorova - One of the best experts on this subject based on the ideXlab platform.
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the Microscopic Anatomy and ultrastructure of the contractile vessel in the sipunculan themiste hexadactyla sato 1930 sipuncula sipunculidea
Russian Journal of Marine Biology, 2014Co-Authors: A V Adrianov, A S MaiorovaAbstract:The Microscopic Anatomy and ultrastructure of the contractile vessel of the sipunculan Themiste hexadactyla (Sato, 1930) from Vostok Bay (the Sea of Japan) were studied by histological and electron microscope methods. The ultrastructural features of the internal (endothelium) and external (coelothelium) lining of the contractile vessel are described and illustrated. Numerous macromolecular filters, the so-called “double diaphragms,” were found in the external coelothelium facing the cavity of the trunk coelom. This suggests a possible filtration from the tentacular coelom into the trunk coelom though the contractile vessel wall. The Microscopic peculiarities of the main tube of the contractile vessel and its numerous lateral branches twining around several internal organs are described in detail. The contractile vessel is polyfunctional: it can act as the main reservoir for the cavity fluid during the withdrawal of the tentacular crown and performs the functions of the distribution system in sipunculans.
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the Microscopic Anatomy and ultrastructure of the nephridium of the sipunculan themiste hexadactyla sato 1930 sipuncula sipunculidea
Russian Journal of Marine Biology, 2014Co-Authors: A V Adrianov, A S MaiorovaAbstract:The Microscopic Anatomy and ultrastructure of the nephridia of the sipunculan Themiste hexadactyla (Sato, 1930) from the Sea of Japan were studied by the histological and electron Microscopic methods. The fine structures of the ciliary funnel, muscular “tongue,” excretory sac, and excretory tube of the nephridium were described. The ultrastructural features of the excretory epithelium, cupola-shaped epithelial infoldings, excretory canals, and muscular layer in the extracellular matrix of the nephridial wall were examined and described in detail. The ultrastructure of the nephridial coelomic epithelium composed of podocytes with long processes and multiciliary cells was also examined and illustrated. Characteristic cell contacts between the processes of podocytes, viz., paired “double diaphragms,” were described and illustrated for the first time.
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Microscopic Anatomy and ultrastructure of a Polian vessel in the sipunculan Thysanocardia nigra Ikeda, 1904 from the Sea of Japan
Russian Journal of Marine Biology, 2002Co-Authors: Andrey V. Adrianov, A S MaiorovaAbstract:The Microscopic Anatomy and ultrastructure of a Polian vessel have been studied in the sipunculan Thysanocardia nigra Ikeda, 1904 from the Sea of Japan using the methods of histology and electron microscopy. We describe ultrastructural features of the inner and outer coelothelium, which is constructed of podocytes and multiciliary cells. Between the processes of the podocyte cells, we found double diaphragms that are considered characteristic macromolecular filters. We conclude from an analysis of the ultrastructural features of the vessel wall that coelomic fluid may be filtered from the tentacular coelom to the trunk coelom via the wall of the Polian vessel.
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Microscopic Anatomy and ultrastructure of nephridium in the sipunculan thysanocardia nigra ikeda 1904 from the sea of japan
2002Co-Authors: A V Adrianov, A S Maiorova, V V MalakhovAbstract:The Microscopic Anatomy and ultrastructure of nephridium have been studied in the sipunculan Thysanocardia nigra Ikeda, 1904 (Sipuncula, Sipunculidea) from the Sea of Japan using histological and electron Microscopic techniques (SEM and TEM). This paper describes ultrastructural features of nephridial epithelium, muscle grid, and coelomic epithelium on the surface of the nephridium, the area of the ciliary funnel, and the “tongue.” Several types of cells were distinguished in the excretory tube of the nephridium: (1) a columnar epithelium of the excretory bunches; (2) a cubical or flattened epithelium of flask-shaped infoldings; and (3) granulocytes that migrate from the coelom to the extracellular matrix of the nephridial wall. The system of podocytes and multiciliary cells were described in the nephridial coelothelium. Two types of secretion of nephridial epithelium have been discovered: a merocrine secretion of columnar cells and an apocrine secretion of cells of the flask-shaped infoldings. Using ultrastructural data, two zones of filtration through the wall of excretory tube have been found, namely (1) the tips of flask-shaped infoldings (via the extracellular matrix and microvillary canals between the epithelial cells) and (2) areas between the flask-shaped infoldings (via the contacts of podocytes, extracellular matrix, and the basal labyrinth of the columnar cells). Unlike previously studied representatives of the genus Phascolosoma, no coelomic epithelium is present on the tips of the flask-shaped infoldings in Th. nigra. This data on the Anatomy and histology allow us to conclude that the funnel only works like a gonoduct.
A V Adrianov - One of the best experts on this subject based on the ideXlab platform.
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the Microscopic Anatomy and ultrastructure of the contractile vessel in the sipunculan themiste hexadactyla sato 1930 sipuncula sipunculidea
Russian Journal of Marine Biology, 2014Co-Authors: A V Adrianov, A S MaiorovaAbstract:The Microscopic Anatomy and ultrastructure of the contractile vessel of the sipunculan Themiste hexadactyla (Sato, 1930) from Vostok Bay (the Sea of Japan) were studied by histological and electron microscope methods. The ultrastructural features of the internal (endothelium) and external (coelothelium) lining of the contractile vessel are described and illustrated. Numerous macromolecular filters, the so-called “double diaphragms,” were found in the external coelothelium facing the cavity of the trunk coelom. This suggests a possible filtration from the tentacular coelom into the trunk coelom though the contractile vessel wall. The Microscopic peculiarities of the main tube of the contractile vessel and its numerous lateral branches twining around several internal organs are described in detail. The contractile vessel is polyfunctional: it can act as the main reservoir for the cavity fluid during the withdrawal of the tentacular crown and performs the functions of the distribution system in sipunculans.
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the Microscopic Anatomy and ultrastructure of the nephridium of the sipunculan themiste hexadactyla sato 1930 sipuncula sipunculidea
Russian Journal of Marine Biology, 2014Co-Authors: A V Adrianov, A S MaiorovaAbstract:The Microscopic Anatomy and ultrastructure of the nephridia of the sipunculan Themiste hexadactyla (Sato, 1930) from the Sea of Japan were studied by the histological and electron Microscopic methods. The fine structures of the ciliary funnel, muscular “tongue,” excretory sac, and excretory tube of the nephridium were described. The ultrastructural features of the excretory epithelium, cupola-shaped epithelial infoldings, excretory canals, and muscular layer in the extracellular matrix of the nephridial wall were examined and described in detail. The ultrastructure of the nephridial coelomic epithelium composed of podocytes with long processes and multiciliary cells was also examined and illustrated. Characteristic cell contacts between the processes of podocytes, viz., paired “double diaphragms,” were described and illustrated for the first time.
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Microscopic Anatomy and ultrastructure of nephridium in the sipunculan thysanocardia nigra ikeda 1904 from the sea of japan
2002Co-Authors: A V Adrianov, A S Maiorova, V V MalakhovAbstract:The Microscopic Anatomy and ultrastructure of nephridium have been studied in the sipunculan Thysanocardia nigra Ikeda, 1904 (Sipuncula, Sipunculidea) from the Sea of Japan using histological and electron Microscopic techniques (SEM and TEM). This paper describes ultrastructural features of nephridial epithelium, muscle grid, and coelomic epithelium on the surface of the nephridium, the area of the ciliary funnel, and the “tongue.” Several types of cells were distinguished in the excretory tube of the nephridium: (1) a columnar epithelium of the excretory bunches; (2) a cubical or flattened epithelium of flask-shaped infoldings; and (3) granulocytes that migrate from the coelom to the extracellular matrix of the nephridial wall. The system of podocytes and multiciliary cells were described in the nephridial coelothelium. Two types of secretion of nephridial epithelium have been discovered: a merocrine secretion of columnar cells and an apocrine secretion of cells of the flask-shaped infoldings. Using ultrastructural data, two zones of filtration through the wall of excretory tube have been found, namely (1) the tips of flask-shaped infoldings (via the extracellular matrix and microvillary canals between the epithelial cells) and (2) areas between the flask-shaped infoldings (via the contacts of podocytes, extracellular matrix, and the basal labyrinth of the columnar cells). Unlike previously studied representatives of the genus Phascolosoma, no coelomic epithelium is present on the tips of the flask-shaped infoldings in Th. nigra. This data on the Anatomy and histology allow us to conclude that the funnel only works like a gonoduct.
V V Malakhov - One of the best experts on this subject based on the ideXlab platform.
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Microscopic Anatomy of the axial complex in the starfish Asterias rubens (Echinodermata, Asteroidea)
Biology Bulletin, 2013Co-Authors: O. V. Ezhova, E. A. Lavrova, V V MalakhovAbstract:The axial complex is one of the most characteristic features of echinoderms. Descriptions of it in classic papers are contradictory. The present paper provides data on the Microscopic Anatomy of the axial complex in the starfish Asterias rubens restudied using histological techniques. The axial complex is located in the wall of the interradius CD; it is elongated in the oral-aboral direction. The stone canal in its aboral end communicates with the axial coelom; in its oral end, it communicates with the water-vascular ring canal. The axial coelom opens to the madreporic ampulla of the stone canal on its aboral end and to the axocoel perihemal coelom on the oral end. The axial organ is formed by the blood vessel network between the basal laminae of the pericardial, axial, and perihemal coelothelia. In Asterias rubens , the heart is a part of the axial organ, which divides the latter into the true axial and pericardial parts. The extensive axial (oral) part of the axial organ opens to the oral blood ring, which is situated in the mesentery between the perihemal coeloms. The smaller, pericardial (aboral), part of the axial organ opens to the hemocoel of the body wall. The genital coelom represents an integral part of the axial complex since one of the five gonad blood lacunae located in the interradius CD communicates with the heart and axial organ vessels. The mistakes and inaccuracies extant in the scientific literature about the Anatomy of the asteroid axial complex are discussed. The blood circulation into the axial organ occurs predominantly from the aboral side to the oral side of starfish.
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Microscopic Anatomy and ultrastructure of the nervous system of phoronopsis harmeri pixell 1912 lophophorata phoronida
Russian Journal of Marine Biology, 2009Co-Authors: E N Temereva, V V MalakhovAbstract:The Microscopic Anatomy and ultrastructure of the nervous system of Phoronopsis harmeri was investigated using histological techniques and electron microscopy. The collar nerve ring is basically formed by circular nerve fibers originating from sensitive cells of tentacles. The dorsal nerve plexus principally consists of large motor neurons. It is shown for the first time that the sensitive collar nerve ring immediately passes into the motor dorsal nerve plexus. The basic components of the nervous system have similar cytoarchitectonics and a layered structure. The first layer is formed by numerous nerve fibers surrounded by the processes of glia-like cells. The bodies of glia-like cells constitute the second layer. The third layer consists of neuron bodies overarched by the bodies of epidermal cells. The giant nervous fiber is accompanied by more than one hundred nerve fibers of a common structure and, thus, marks the true longitudinal nerve. The phoronids possess one or two longitudinal nerves. It is supposed that the plexus nature of the nervous system in phoronids may be related to their phylogenesis. A comparison of the nervous system organization and body plans among the Lophophorata suggests that the nervous system of phoronids cannot be considered as a reductive variant of the brachiopod nervous system. At the same time, the structure of the nervous system of bryozoans can be derived from that of phoronids.
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Microscopic Anatomy and ultrastructure of nephridium in the sipunculan thysanocardia nigra ikeda 1904 from the sea of japan
2002Co-Authors: A V Adrianov, A S Maiorova, V V MalakhovAbstract:The Microscopic Anatomy and ultrastructure of nephridium have been studied in the sipunculan Thysanocardia nigra Ikeda, 1904 (Sipuncula, Sipunculidea) from the Sea of Japan using histological and electron Microscopic techniques (SEM and TEM). This paper describes ultrastructural features of nephridial epithelium, muscle grid, and coelomic epithelium on the surface of the nephridium, the area of the ciliary funnel, and the “tongue.” Several types of cells were distinguished in the excretory tube of the nephridium: (1) a columnar epithelium of the excretory bunches; (2) a cubical or flattened epithelium of flask-shaped infoldings; and (3) granulocytes that migrate from the coelom to the extracellular matrix of the nephridial wall. The system of podocytes and multiciliary cells were described in the nephridial coelothelium. Two types of secretion of nephridial epithelium have been discovered: a merocrine secretion of columnar cells and an apocrine secretion of cells of the flask-shaped infoldings. Using ultrastructural data, two zones of filtration through the wall of excretory tube have been found, namely (1) the tips of flask-shaped infoldings (via the extracellular matrix and microvillary canals between the epithelial cells) and (2) areas between the flask-shaped infoldings (via the contacts of podocytes, extracellular matrix, and the basal labyrinth of the columnar cells). Unlike previously studied representatives of the genus Phascolosoma, no coelomic epithelium is present on the tips of the flask-shaped infoldings in Th. nigra. This data on the Anatomy and histology allow us to conclude that the funnel only works like a gonoduct.
Andrey V. Adrianov - One of the best experts on this subject based on the ideXlab platform.
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Microscopic Anatomy of the Tentacles of Thysanocardia nigra Ikeda, 1904 (Sipuncula) from the Sea of Japan
Publications of the Seto Marine Biological Laboratory, 2005Co-Authors: Andrey V. Adrianov, Vladimir V. Malakhov, Anastassya MayorovaAbstract:Fine morphology of the tentacular apparatus of the sipunculan Thysanocardia nigra Ikeda, 1904 was conducted as a part of a larger study of Microscopic Anatomy in the species. The tentacular apparatus is composed of two rings of tentacles, the dorsal and oral crowns. The dorsal, or nuchal, crown consists of an arc of nuchal tentacles dorsally enclosing the heart -shaped nuchal organ. The oral disk carries numerous peripheral tentacles arranged in oral crown surrounding the mouth. Peripheral tentacles are arranged in paired rows, additional tentacles being developed posteriorly so as to form a radial series of U -shaped festoons. The parallel festoons extend down the oral disk and run alongside the spherical head. New pairs of festoons appear at the base of the nuchal crown. The tentacles are heart-shaped in cross section, the oral surface being widest. The nuchal tentacles face the oral disk by the oral surface while the peripheral, or oral, tentacles are twisted at the base at nearly right angles, so to face a ciliary groove of the corresponding festoon. The central groove of festoon is composed of a median ridge bordered by longitudinal lateral ridges with long cilia. The oral surface of tentacles is constructed of a multiciliated, pseudostratified, columna! epithelium with some intraepidermal mucous cells. There are three longitudinal tentacular canals lined by peritoneum. Hemerythrocytes flow through the lumen of the canals. Tentacles and grooves of festoons form a filtering system upon which food particles can be trapped. The filtering apparatus of Thysanocardia shows remarkable similarities with a filtering system of sabellid polychaetes.
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Microscopic Anatomy and ultrastructure of a Polian vessel in the sipunculan Thysanocardia nigra Ikeda, 1904 from the Sea of Japan
Russian Journal of Marine Biology, 2002Co-Authors: Andrey V. Adrianov, A S MaiorovaAbstract:The Microscopic Anatomy and ultrastructure of a Polian vessel have been studied in the sipunculan Thysanocardia nigra Ikeda, 1904 from the Sea of Japan using the methods of histology and electron microscopy. We describe ultrastructural features of the inner and outer coelothelium, which is constructed of podocytes and multiciliary cells. Between the processes of the podocyte cells, we found double diaphragms that are considered characteristic macromolecular filters. We conclude from an analysis of the ultrastructural features of the vessel wall that coelomic fluid may be filtered from the tentacular coelom to the trunk coelom via the wall of the Polian vessel.
Robert H Riddell - One of the best experts on this subject based on the ideXlab platform.
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the Microscopic Anatomy of the esophagus including the individual layers specialized tissues and unique components and their responses to injury
Annals of the New York Academy of Sciences, 2018Co-Authors: Xuchen Zhang, Deepa T Patil, Robert D Odze, Lei Zhao, Mikhail Lisovsky, Maha Guindi, Robert H RiddellAbstract:: The esophagus, a straight tube that connects the pharynx to the stomach, has the complex architecture common to the rest of the gastrointestinal tract with special differences that relate to its function as a conduit of ingested substances. For instance, it has submucosal glands that are unique and have a specific protective function. It has a squamous lining that exists nowhere else in the gut except the anus and it has a different submucosal nerve plexus when compared to the stomach and intestines. All of the layers of the esophageal wall and the specialized structures including blood and lymphatic vessels and nerves have specific responses to injury. The esophagus also has unique features such as patches of gastric mucosa called inlet patches at the very proximal part and it has a special sphincter mechanism at the most distal aspect. This review covers the normal Microscopic Anatomy of the esophagus and the patterns of reaction to stress and injury of each layer and each special structure.