An experimental approach to the problem of the derivation of the vaginal epithelium

Development ◽  
1965 ◽  
Vol 14 (3) ◽  
pp. 213-222
Author(s):  
John-Gunnar Forsberg
Keyword(s):  
Present Author ◽  
Experimental Approach ◽  
Squamous Epithelium ◽  
Anterior Part ◽  
Posterior Part ◽  
Vaginal Epithelium ◽  
Estradiol Treatment ◽  
Detailed Review ◽  
Stratified Squamous Epithelium ◽  
Dual Origin

In earlier papers the present author (Forsberg, 1963, 1965a, b; Forsberg & Olivecrona, 1964) has presented studies of the derivation and differentiation of the vaginal epithelium by morphological, histochemical and autoradiographic methods and by counts of mitotic rates. These investigations favour the view that the vaginal epithelium in mouse and rat has a dual origin: the anterior part being derived from the Müllerian epithelium and the posterior part from the sinus epithelium. This means that in these species the pseudostratified columnar Müllerian epithelium in the vaginal region undergoes a transformation into a stratified squamous epithelium. The possible mechanism behind this transformation has been discussed (Forsberg & Olivecrona, 1965). Results from estradiol treatment of neonatal mice during the differentiation of the vaginal epithelium support the above-mentioned investigations. (For a detailed review on the problem of the derivation of the vaginal epithelium, see Forsberg, 1963.)

Stomatogenesis and morphological re-description of the marine ciliate,Philasterides armatalis(Protozoa: Ciliophora: Scuticociliatida)

2008 ◽  
Vol 88 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Xiaozhong Hu ◽  
Alan Warren ◽  
Weibo Song
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Differential Interference Contrast ◽  
Marine Ciliate ◽  
Contrast Microscope ◽  
Protozoa Ciliophora ◽  
Differential Interference Contrast Microscope ◽  
Planktonic Ciliate ◽  
Dual Origin

The stomatogenesis and morphology of the marine planktonic ciliatePhilasterides armataliscollected from mollusc-culturing waters off the coast of Qingdao, China, were studied using a differential interference contrast microscope for observationsin vivoand protargol impregnation. In terms of its infraciliature, this species possesses typical characteristics of the genusPhilasterides: bipartite paroral membrane, the anterior part double-rowed and the posterior part in a zig-zag-formation, and three well-defined membranelles arranged inParanophrys-pattern. This investigation confirms the dual origin of the buccal apparatus in the opisthe, one derived from the scutica and the other from the paroral membrane. Its stomatogenesis belongs to the ‘Philasterides’ sub-type, although it differs from its only congenerP. armata, in that paroral membrane 1 gives rise to the paroral membrane and the scutica in the proter, and paroral membrane 2 forms the paroral membrane, membranelles 1 and 2 and the scutica in the opisthe. Based on stomatogenetic data, the phylogenetic positions of several genera in the suborder Philasterina are reconsidered.

Junction of the Epithelium and Lamina Propria of the Bovine Rumen Mucosa

1967 ◽  
Vol 25 ◽  
pp. 68-69
Author(s):  
Al W. Stinson
Keyword(s):  
Osmium Tetroxide ◽  
Squamous Epithelium ◽  
Short Chain Fatty Acids ◽  
Chloride Ions ◽  
Fermentation Products ◽  
Ruminant Species ◽  
Protective Shield ◽  
Stratified Squamous Epithelium ◽  
Lead Hydroxide ◽  
Acetic Acids

The stratified squamous epithelium which lines the ruminal compartment of the bovine stomach performs at least three important functions. (1) The upper keratinized layer forms a protective shield against the rough, fibrous, constantly moving ingesta. (2) It is an organ of absorption since a number of substances are absorbed directly through the epithelium. These include short chain fatty acids, potassium, sodium and chloride ions, water, and many others. (3) The cells of the deeper layers metabolize butyric acid and to a lesser extent propionic and acetic acids which are the fermentation products of rumen digestion. Because of the functional characteristics, this epithelium is important in the digestive process of ruminant species which convert large quantities of rough, fibrous feed into energy.Tissue used in this study was obtained by biopsy through a rumen fistula from clinically healthy, yearling holstein steers. The animals had been fed a typical diet of hay and grain and the ruminal papillae were fully developed. The tissue was immediately immersed in 1% osmium tetroxide buffered to a pH of 7.4 and fixed for 2 hrs. The tissue blocks were embedded in Vestapol-W, sectioned with a Porter-Blum microtome with glass knives and stained with lead hydroxide. The sections were studied with an RCA EMU 3F electron microscope.

Fine structure of the rectal papillae of the oriental fruuit fly, Dacus dorsalis Hendel (Tephritidae, Diptera Insecta)

1990 ◽  
Vol 48 (3) ◽  
pp. 498-499
Author(s):  
Len Wen-Yung ◽  
Mei-Jung Lin
Keyword(s):  
Fine Structure ◽  
Cell Membrane ◽  
Intercellular Space ◽  
Anterior Part ◽  
Apical Cell ◽  
Posterior Part ◽  
Apical Cell Membrane ◽  
Dacus Dorsalis ◽  
Radial Cell ◽  
Circular Base

Four cone-shaped rectal papillae locate at the anterior part of the rectum in Dacus dorsalis fly. The circular base of the papilla protrudes into the haemolymph (Fig. 1,2) and the rest cone-shaped tip (Fig. 2) inserts in the rectal lumen. The base is surrounded with the cuticle (Fig. 5). The internal structure of the rectal papilla (Fig. 3) comprises of the cortex with the columnar epithelial cells and a rod-shaped medulla. Between them, there is the infundibular space and many trabeculae connect each other. Several tracheae insert into the papilla through the top of the medulla, then run into the cortical epithelium and locate in the intercellular space. The intercellular sinuses distribute in the posterior part of the rectal papilla.The cortex of the base divides into about thirty segments. Between segments there is a radial cell (Fig. 4). Under the cuticle, the apical cell membrane of the cortical epithelium is folded into a regular border of leaflets (Fig. 5).

scholarly journals The genus Gennadas (Benthesicymidae: Decapoda): morphology of copulatory characters, phylogeny and coevolution of genital structures

2017 ◽  
Vol 4 (12) ◽  
pp. 171288 ◽  
Author(s):  
Alexander L. Vereshchaka ◽  
Anastasia A. Lunina ◽  
Jørgen Olesen
Keyword(s):  
New Species ◽  
Anterior Part ◽  
Phylogenetic Analyses ◽  
Posterior Part ◽  
Key To Species ◽  
Internal Part ◽  
Species Groups ◽  
Aristaeomorpha Foliacea ◽  
External Part ◽  
Scanning Electron

Species within Gennadas differ from each other largely only in male (petasma) and female (thelycum) copulatory characters, which were restudied in scanning electron microscopy and used as a basis for phylogenetic analyses. Twenty-six petasma characters and 49 thelycum characters were identified. All 16 recognized species of Gennadas and Aristaeomorpha foliacea (outgroup) were included as terminals. Four robust monophyletic clades were retrieved, described and diagnosed as new species groups. The thelycum characters had greater impact on tree topology and supported deeper nodes than did the petasma characters. We hypothesize that features of the thelycum evolved first followed by aspects of the petasma. Relatively more conservative characters include parts of the sternites of the thelycum and of the petasma, while the scuti and protuberances on the thelycum and the shape and subdivisions of the petasma lobes are evolutionarily plastic. We identified two groups of copulatory characters, which are likely coupled functionally and interlinked evolutionarily: (i) the external part of the petasma and the posterior part of the thelycum and (ii) the internal part of the petasma and anterior part of the thelycum. We reconstruct possible mating position during copulation for each of the new species groups presented here. We also present an updated key to genera of Benthesicymidae and key to species of Gennadas .

Interacting functions of snail, twist and huckebein during the early development of germ layers in Drosophila

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1137-1150 ◽  
Author(s):  
R. Reuter ◽  
M. Leptin
Keyword(s):  
Transcription Factors ◽  
Digestive Tract ◽  
Early Development ◽  
Target Genes ◽  
Anterior Part ◽  
Posterior Part ◽  
Germ Layers ◽  
Mesoderm Development ◽  
Ventral Furrow

Two zygotic genes, snail (sna) and twist (twi), are required for mesoderm development, which begins with the formation of the ventral furrow. Both twi and sna are expressed ventrally in the blastoderm, encode transcription factors and promote the invagination of the ventral furrow by activating or repressing appropriate target genes. However, sna and twi alone do not define the position of the ventral furrow, since they are also expressed in ventral cells that do not invaginate. We show that huckebein (hkb) sets the anterior and the posterior borders of the ventral furrow, but acts by different modes of regulation. In the posterior part of the blastoderm, hkb represses the expression of sna in the endodermal primordium (which we suggest to be adjacent to the mesodermal primordium). In the anterior part, hkb antagonizes the activation of target genes by twi and sna. Here, bicoid permits the co-expression of hkb, sna and twi, which are all required for the development of the anterior digestive tract. We suggest that mesodermal fate is determined where sna and twi but not hkb are expressed. Anteriorly hkb together with sna determines endodermal fate, and hkb together with sna and twi are required for foregut development.

Note on the Transformation of Ciliated into Stratified Squamous Epithelium as a result of the Application of Friction

1890 ◽  
Vol 16 ◽  
pp. 119-120 ◽  
Author(s):  
John Berry Haycraft ◽  
E. W. Carlier
Keyword(s):  
Mucous Membrane ◽  
Squamous Epithelium ◽  
The Other ◽  
Ciliated Epithelium ◽  
Deep Groove ◽  
Stratified Squamous Epithelium ◽  
Trachealis Muscle

(Abstract.)In man, in the rabbit, and some other animals the trachea is built up of a series of cartilaginous rings incomplete behind; the rings being completed in this position by the trachealis muscle.The mucous membrane forms a smooth cylindrical lining for the whole tube, and is covered by a ciliated epithelium.In the cat and dog the cartilage rings completely encircle the trachea, and overlap posteriorly, and the trachealis muscle, which is well developed, is placed outside the cartilage, and has a powerful action in varying the diameter of the tube.When this muscle contracts the overlapping ends of the cartilage ride one upon another, and the projecting ends form a vertical ridge down the inside of the trachea, which can be readily seen on slitting the organ open. This ridge is separated by a deep groove from the other end of the plate.

Zimmermann-Laband Syndrome in an Infant with an Atypical Histologic Finding

2005 ◽  
Vol 8 (6) ◽  
pp. 654-657 ◽  
Author(s):  
Mehmet Emre Atabek ◽  
Ozgur Pirgon ◽  
Ahmet Sert ◽  
Hatice Toy
Keyword(s):  
Squamous Epithelium ◽  
Male Infant ◽  
Histologic Finding ◽  
Histopathologic Finding ◽  
Stratified Squamous Epithelium ◽  
Hands And Feet ◽  
Excised Tissue

Zimmermann-Laband syndrome is an inherited disorder that is characterized by abnormalities of the head, face, hands, and feet. Most children with this disorder have generalized hypertrichosis, large gingivae, and hypoplasia of the fingernails and toenails. We report a male infant who exhibited typical features of Zimmermann-Laband syndrome with an unusual histopathologic finding. Excised tissue from the infant's gingivae showed papillary projections that were composed of hyperplastic stratified squamous epithelium with different amounts of keratinization.

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