Ultrastructure of the Pharynx and Some Parenchyma Cells of Zeuxapta-Seriolae and Paramicrocotyloides-Reticularis (Monogenea, Polyopisthocotylea, Microcotylidae)

1986 ◽  
Vol 34 (4) ◽  
pp. 473 ◽  
Author(s):  
K Rohde
Keyword(s):  
Endoplasmic Reticulum ◽  
Connective Tissue ◽  
Cell Membrane ◽  
Basal Lamina ◽  
Cell Membranes ◽  
Granular Endoplasmic Reticulum ◽  
Loose Connective Tissue ◽  
Parenchyma Cells ◽  
Glandular Cells ◽  
Tissue Cells

The ultrastructure of the pharynx of Zeuxapta seriolae and Paramicrocotyloides reticularis (Monogenea : Microcotylidae) is described. The pharynx of both species is surrounded by a thick sheath resembling a basal lamina. It contains layers of longitudinal, circular and radial muscles, glandular cells, smaller cells interpreted as connective tissue cells, axons, and loose connective tissue. The cell bodies of the glandular cells are subdivided by deep invaginations of cell membranes; the cytoplasm is rich in granular endoplasmic reticulum and golgi complexes. The pharyngeal lumen is branched and lined with a layer of cytoplasm which contains numerous surface lamellae, branched 'supportive' lamellae, and vesicles. A body consisting of stacks of tubules, and associated with axons, is interpreted as a proprioceptor. Bacteria were found in the cytoplasm of some parts of the pharynx of Z. seriolae, particularly near the lumen. In Z. seriolae, three types of parenchyma cells near the pharynx were examined. All have deep invaginations of the cell membrane which, at least in some cells, are anchored near the nucleus by means of desmosomes, and which contain processes of adjacent cells.

The fine structure of Leucocytozoon simondi. V. The oocyst

1972 ◽  
Vol 50 (6) ◽  
pp. 707-711 ◽  
Author(s):  
Sherwin S. Desser
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Basal Lamina ◽  
Central Core ◽  
Granular Endoplasmic Reticulum ◽  
Midgut Epithelium ◽  
Stage Of Development ◽  
Peripheral Cytoplasm

Following penetration through the midgut epithelium of Simulium rugglesi, ookinetes of Leucocytezoon simondi round up beneath the basal lamina and transform into young oocysts. These spherical, walled structures contain a large central core of crystalloid material. Dividing nuclei are seen in the peripheral cytoplasm, which is characterized by several concentric layers of granular endoplasmic reticulum. In a succeeding stage of development the trilaminar plasma membrane appears intermittently doubled, and bud-like outgrowths occur in these thickened areas. At this stage the crystalloid material is dispersed throughout the cytoplasm. A nucleus, an elongate mitochondrion, and some crystalloid material move into each forming sporozoite, which continues to grow at the expense of the residual cytoplasm.

scholarly journals The Influence of High Potassium Depolarization and Acetylcholine on Calcium Exchange in the Rat Uterus

1966 ◽  
Vol 49 (6) ◽  
pp. 1299-1317 ◽  
Author(s):  
CASEY van BREEMEN ◽  
E. E. DANIEL
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Membrane ◽  
Cell Membranes ◽  
Cytoplasmic Calcium ◽  
Calcium Efflux ◽  
Rat Uterus ◽  
Potassium Depolarization ◽  
High Potassium ◽  
Calcium Exchange

Net and radioactive calcium movements were studied in the rat uterus during stimulation with acetylcholine and high potassium solutions. High potassium did not affect the efflux of intracellular Ca45, but was able to release Ca45 from a small parallel Ca fraction which was believed to be located in the cell membranes. High potassium did markedly slow the influx of Ca45 and caused a net calcium efflux. Acetylcholine had no effect on calcium movements in polarized myometrium, but it increased the Ca45 influx in depolarized uteri. Ca45 taken up during contraction exchanged more slowly during subsequent efflux than Ca45 taken up at rest. The results were interpreted as supporting the hypothesis that myometrial contraction is induced by a release of calcium from the inside of the cell membrane and the endoplasmic reticulum, and relaxation follows the removal of ionic cytoplasmic calcium by these same structures.

Fine structure of the apical rim—mesenchyme complex during limb morphogenesis in man

Development ◽  
1973 ◽  
Vol 29 (1) ◽  
pp. 117-131
Author(s):  
Robert O. Kelley
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Basal Lamina ◽  
Granular Endoplasmic Reticulum ◽  
Limb Morphogenesis ◽  
Junctional Complexes

Ultrastructure of the apical rim–basal lamina–mesenchyme complex in man during Horizons 15–18 is correlated with the development of limbs. 1. Apical epithelium is a complicated tissue exhibiting surface microvilli, junctional complexes, free ribosomes, elaborate Golgi centers, glycogen and scanty granular endoplasmic reticulum. 2. The apical rim thickens during stages 15 and 16, remaining multilayered at digital tips and thinning adjacent to zones of necrosis by stages 17 and 18. Epithelial thinning may be a response to lack of ‘maintenance factor’. 3. A continuous basal lamina is present during these stages. Collagen-like fibrils are numerous in interdigital zones of necrosis and sparse at tips of digital blastemata. 4. The presence of oriented microfilaments in interdigital epithelium suggests active invagination during morphogenesis of fingers in man.

scholarly journals The Fine Structure of the Epithelial Cells of the Mouse Prostate

1960 ◽  
Vol 7 (3) ◽  
pp. 511-513 ◽  
Author(s):  
David Brandes ◽  
Adolfo Portela
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Muscle ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Connective Tissue ◽  
Cell Membrane ◽  
Secretory Cells ◽  
Ventral Lobe ◽  
Cytoplasmic Matrix ◽  
Mouse Prostate

The fine structure of the epithelial cells of one component of the prostatic complex of the mouse—the ventral lobe—has been investigated by electron microscopy. This organ is composed of small tubules, lined by tall simple cuboidal epithelium, surrounded by smooth muscle and connective tissue. Electron micrographs of the epithelial cells of the ventral lobe show these to be limited by a cell membrane, which appears as a continuous dense line. The nucleus occupies the basal portion of the cell and the nuclear envelope consists of two membranes. The cytoplasmic matrix is of moderately low density. The endoplasmic reticulum consists of elongated, circular, and oval profiles representing the cavities of this system bounded by rough surfaced membranes. The Golgi apparatus appears localized in a region between the apical border and the nucleus, and is composed of the usual elements found in secretory cells (3, 9). At the base of the cells, a basement membrane is visible in close contact with the outer aspect of the cell membrane. A space of varying width, which seems to be occupied by connective tissue, separates the epithelial cells from the surrounding smooth muscle fibers and the blood vessels. Bodies with the appearance of portions of the cytoplasm, mitochondria, or profiles of the endoplasmic reticulum can be seen in the lumina of the acini and on the bases of these pictures and others of the apical region the mechanism of secretion by these cells is discussed. The fine structural organization of these cells is compared with that of another component of the mouse prostate—the coagulating gland.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Increased matrix gene expression by glucose in rat neural connective tissue cells in culture

Diabetes ◽  
1991 ◽  
Vol 40 (5) ◽  
pp. 605-611 ◽  
Author(s):  
P. Muona ◽  
J. Peltonen ◽  
S. Jaakkola ◽  
J. Uitto
Keyword(s):  
Gene Expression ◽  
Connective Tissue ◽  
Cells In Culture ◽  
Matrix Gene ◽  
Tissue Cells

scholarly journals I. A contribution to the anatomy of the ductless glands and lymphatic system of the angler fish ( Lophius piscatorius )

1927 ◽  
Vol 215 (421-430) ◽  
pp. 1-56 ◽  
Keyword(s):  
Connective Tissue ◽  
Lymphatic System ◽  
Loose Connective Tissue ◽  
Mode Of Life ◽  
Better Than ◽  
Considerable Size

The Angler ( Lophius piscatorius ) is a fish much modified for a bottom habit, and apart from many peculiarities of form and structure associated with this particular mode of life, is remarkable for the looseness of its skin and the abundance of soft connective tissue that separates it from the underlying fascia and muscles. Within this layer of loose connective tissue lie many of the larger trunks of the lymphatic system, mostly of very considerable size and easy to inject. The fish thus furnishes material better than most for the study of this system.

scholarly journals A DISTINCTIVE CELL CONTACT IN THE RAT ADRENAL CORTEX

1972 ◽  
Vol 53 (1) ◽  
pp. 148-163 ◽  
Author(s):  
Daniel S. Friend ◽  
Norton B. Gilula
Keyword(s):  
Cell Membrane ◽  
Adrenal Cortex ◽  
Cell Membranes ◽  
Freeze Fracture ◽  
Typical Feature ◽  
Cell Contact ◽  
Cortical Cells ◽  
Cell Dispersion ◽  
Extensive Cell ◽  
Distinctive Cell

Extensive cell contacts which resemble septate junctions occur between cells in the three major zones of the rat adrenal cortex. Characteristically, they extend between small intercellular canaliculi and the periendothelial space, frequently interrupted by gap junctions and rarely by desmosomes. Zonulae occludentes have not been identified in the adrenal cortex. Along this distinctive cell contact, the cell membranes of apposing cells are separated by 210–300 a bisected by irregularly spaced 100–150-A extracellular particles which are often circular in profile. In lanthanum preparations, these particles appear to form a continuous chain throughout the intercellular space and are visualized as an alveolate structure in sections parallel to the plane of the cell membrane. The cell membrane in the area of septate-like contact does not differ from nonjunctional areas of the cell membrane in freeze-fracture replicas. The cell contact retains its integrity after cell dispersion and after the separation of cell membranes from disrupted cells. The intercellular particles also persist after brief extraction in lipid solvents. Besides adherence, possible functions of this adrenal contact include maintenance of the width of the extracellular space, the provision of channels between intercellular canaliculi and the bloodstream, and utilization as cation depots. Similar structures are also present between adrenal cortical cells of several other species and between interstitial cells of the testis. This type of cell contact may, in fact, be a typical feature of steroid-hormone-secreting tissues in vertebrates.

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