The Biology of Bothrimonus (=Diplocotyle) (Pseudophyllidea: Cestoda): Detailed Morphology and Fine Structure

1974 ◽  
Vol 31 (2) ◽  
pp. 147-153 ◽  
Author(s):  
M. D. B. Burt ◽  
I. M. Sandeman
Keyword(s):  
Electron Microscopy ◽  
Nervous System ◽  
Fine Structure ◽  
Functional Morphology ◽  
Light And Electron Microscopy ◽  
Nerve Fibers ◽  
Fish Host ◽  
Extensive System ◽  
And Function

Light and electron microscopy were used to describe the functional morphology of Bothrimonus sturionis in detail. In particular, the musculature, nervous system, osmoregulatory system, and tegument are dealt with, and the findings compared with those of other workers. The musculature of the scolex consists of several interrelated systems, the structure of each being discussed in relation to its function. Associated with the regular nervous system, considered typical of cestodes, is an extensive system of giant nerve fibers. The osmoregulatory system is unusual in that there are lateral "excretory" pores in many proglottides which open directly to the exterior of the worm. The microtriches of the tegument are long, like those of other primitive cestodes, and are covered by a noncellular sheath while the worm is in its gammarid host. The sheath is lost when the worm becomes established in its fish host; the nature and function of the sheath are discussed.

Distribution of adrenomedullin-like immunoreactivity in the rat central nervous system by light and electron microscopy

2000 ◽  
Vol 853 (2) ◽  
pp. 245-268 ◽  
Author(s):  
Julia Serrano ◽  
L.Otto Uttenthal ◽  
Alfredo Martı́nez ◽  
A.Patricia Fernández ◽  
Javier Martı́nez de Velasco ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Central Nervous System ◽  
Nervous System ◽  
Light And Electron Microscopy

Fine Structure of the Eye of a Nudibranch Mollusc, Hermissenda Crassicornis

1967 ◽  
Vol 2 (3) ◽  
pp. 349-358
Author(s):  
R. M. EAKIN ◽  
JANE A. WESTFALL ◽  
M. J. DENNIS
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Optic Nerve ◽  
Light And Electron Microscopy ◽  
The Other ◽  
Sensory Cells ◽  
Nerve Fibres ◽  
Supporting Cells ◽  
Small Bodies ◽  
Receptor Cells

The eye of a nudibranch, Hermissenda crassicornis, was studied by light and electron microscopy. Three kinds of cells were observed: large sensory cells, each bearing at one end an array of microvilli (rhabdomere) and at the other end an axon which leaves the eye by the optic nerve; large pigmented supporting cells; and small epithelial cells, mostly corneal. There are five sensory cells, and the same number of nerve fibres in the optic nerve. The receptor cells contain an abundance of small vesicles, 600-800 Å in diameter. The lens is a spheroidal mass of osmiophilic, finely granular material. A basal lamina and a capsule of connective tissue enclose the eye. In some animals the eye is ‘infected’ with very small bodies, 4-5 µ in diameter, thought to be symbionts.

Effect of basolateral acidification on the frog oxynticopeptic cell

1990 ◽  
Vol 259 (4) ◽  
pp. G564-G570 ◽  
Author(s):  
S. Arvidsson ◽  
K. Carter ◽  
A. Yanaka ◽  
S. Ito ◽  
W. Silen
Keyword(s):  
Electron Microscopy ◽  
Gastric Mucosa ◽  
Light And Electron Microscopy ◽  
Structure And Function ◽  
Intracellular Acidification ◽  
Intracellular Acidosis ◽  
Normal Morphology ◽  
And Function ◽  
Oxynticopeptic Cells

The effects of intracellular acidosis induced by acidification of the basolateral (nutrient) perfusate on the structure and function of the oxynticopeptic cell were studied in in vitro frog gastric mucosa. Changing the pH of the unbuffered nutrient perfusate (UNB) from 7.2 to 3.5 acidified the oxynticopeptic cell with no change in potential difference (PD) or resistance (R). Intracellular pH (pHi), PD, and R were 7.05 +/- 0.01, 16 +/- 1 mV, 165 +/- 7 omega.cm2 before and 6.44 +/- 0.01, 16 +/- 2 mV, 170 +/- 9 omega.cm2 after nutrient acidification. Acid secretion (H+) increased from 0.86 +/- 0.07 to 1.88 +/- 0.18 mu eq.cm-2.h-1. Addition of forskolin to tissues perfused with nutrient pH (pHn) 3.5 decreased PD to 2 +/- 2 mV and further increased H+ to 3.07 +/- 0.19 mu eq.cm-2.h-1. By light and electron microscopy oxynticopeptic cells perfused with UNB, pHn 3.5, appeared normal. Oxynticopeptic cells in tissues pretreated with omeprazole and then exposed to UNB, pHn 3.5, had extensive morphological damage. On increasing the pH of the nutrient perfusate from 3.5 to 7.2 there was prompt recovery of pHi in untreated and forskolin-stimulated mucosae (pHi 6.87 +/- 0.06 and 6.85 +/- 0.04) but no recovery of pHi in tissues pretreated with omeprazole or cimetidine (pHi 6.26 +/- 0.04 and 6.44 +/- 0.06, n = 6, 30 min after reexposure to UNB, pHn 7.2). We conclude that in a secreting mucosa intracellular acidification of the oxynticopeptic cell to pHi 6.4 is associated with normal morphology, PD, R, and increased H+, and that intracellular acidosis is not de facto deleterious.

Observations on the nephridial system of the cestode Moniezia expansa (Rud., 1805)

Parasitology ◽  
1969 ◽  
Vol 59 (2) ◽  
pp. 449-459 ◽  
Author(s):  
R. E. Howells
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Connective Tissue ◽  
Intercellular Space ◽  
Technical Assistance ◽  
Light And Electron Microscopy ◽  
Flame Cell ◽  
Research Scholarship ◽  
Research Facilities

The nephridial system of M. expansa has been studied using light and electron microscopy, and a number of histochemical techniques have been used on sections of the worm. The organization of the nephridial system and the fine structure of the flame cells and the nephridial ducts are described. Pores, which connect the nephridial lumen to the intercellular space of the connective tissue, exist at the junction of a flame cell and a nephridial duct. These pores may be considered nephrostomes and the system therefore is not protonephridial as defined by Hyman (1951).The epithelium lining the nephridial ducts has a structure which suggests that it is metabolically active. It is postulated that the beating of the cilia of the flame cells draws fluid into the ducts via the nephrostomes, with absorption and/or secretion of solutes being carried out by the epithelial cells of the duct walls. The function of the nephridial system is discussed.I am grateful to Professor James Brough for the provision of research facilities at the Department of Zoology, University College, Cardiff, andtoDrD. A. Erasmus for much helpful advice during the course of the work. I wish to thank Professors W. Peters and T. Wilson for critically reading the manuscript and Miss M. Williams and Mr T. Davies for expert technical assistance.I also wish to thank the Veterinary Inspector and his staff at the Roath Abattoir, Cardiff, for their kind co-operation and assistance in obtaining material.The work was carried out under the tenure of an S.R.C. research scholarship.

scholarly journals The Fine Structure of the Wheat Scutellum During Germination

1972 ◽  
Vol 25 (3) ◽  
pp. 469 ◽  
Author(s):  
JG Swift ◽  
TP O'brien
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Wall Material ◽  
Cytological Evidence ◽  
Starch Grains ◽  
Parenchyma Cells ◽  
Cytological Changes

The cytological changes that take place in the scutellar epithelium and parenchyma during the first 5 days of germination are described by light and electron microscopy. Within 6 hr small starch grains appear in the plastids of both cell types and the size and number of starch grains increase gradually as germination proceeds. Later in germination starch disappears again from the plastids in the epithelial cells, but large starch grains still remain in the parenchyma cells. The reserves of the protein bodies are hydrolysed and the residual vacuoles undergo extensive coales-cence. Modifications in the appearance of the wall material of the epithelial cells as these cells elongate are illustrated and possible functional bases for these changes are suggested. The cells of the scutellar epithelium show no cytological evidence for their known functions of diastase secretion and nutrient absorption.

In situ studies on the cytochemistry and ultrastructure of a symbiotic marine dinoflagellate

1968 ◽  
Vol 48 (2) ◽  
pp. 349-366 ◽  
Author(s):  
D. L. Taylor
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Light And Electron Microscopy ◽  
Structural Morphology ◽  
Invertebrate Species ◽  
Algal Symbionts ◽  
Anemonia Sulcata ◽  
Mode Of Life ◽  
Structural Adaptations

The intertidal actinian Anemonia sulcata is known to harbour yellow-brown algal symbionts which are similar in appearance to the zooxanthellae of hermatypic, or reef-building, corals and a number of other invertebrate species. The cytochemistry and structural morphology of the zooxanthella has been studied by light and electron microscopy, to help define it taxonomically and to reveal something about its relations with the actinian. These investigations confirm that it is a dinoflagellate and have revealed several structural adaptations which are formed as a result of the peculiar mode of life adopted by this alga. Of significance is the fine structure of the periplast, which may have a considerable bearing upon the type of relationship which can exist between the host and its symbiont. These findings are discussed in terms of other known instances of algal-invertebrate symbiosis.

Sign in / Sign up

Export Citation Format

Share Document