scholarly journals On the structure and function of the alimentary canal of Tigriopus japonicus (copepoda; harpacticoida). I. Histological structure.

1975 ◽  
Vol 41 (9) ◽  
pp. 929-935 ◽  
Author(s):  
Kazuma YOSHIKOSHI
1939 ◽  
Vol 59 (3) ◽  
pp. 599-646 ◽  
Author(s):  
Vera Fretter

Owing to the comparatively rare occurrence of most tectibranchs it is perhaps not surprising to find that, in spite of the ever-increasing knowledge of the histological structure and functioning of the alimentary canal of molluscs, little attention has been paid in this respect to these forms. The structure of the radula and gizzard has previously aroused interest, but so far as the rest of the alimentary canal is concerned most workers have been content with a somewhat superficial description of the gross morphology such as was given by Vayssière (1880), Bouvier (1893), Pelseneer (1893, 1894), and Guiart (1901). A more recent account of the digestive tract of Philine aperta has been given by Brown (1934), but this includes no histological or physiological consideration.


2011 ◽  
Vol 57 (2) ◽  
pp. 32-35
Author(s):  
L A Bondarenko ◽  
L Iu Sergienko ◽  
N N Sotnik ◽  
A N Cherevko

The pituitary-thyroid axis of young sexually mature rabbits kept under a 24-hour daylight photoperiod was shown to undergo phase-modulated variations of hormonal activity with its initial increase (during the first month) and subsequent progressive decrease (within 2-5 months after the onset of exposure to light). These changes correlated with the time-dependent fall in the blood T3, T4, and TSH levels. Simultaneously, the animals developed pathological changes in the histological structure of the thyroid gland similar to those in patients with secondary or tertiary hypothyroidism. It is concluded that hormonal and structural changes in the thyroid gland during long-term hypopinealism should be regarded as an experimental model of hypothyroidism of neuroendocrine origin.


1938 ◽  
Vol 59 (2) ◽  
pp. 267-307 ◽  
Author(s):  
Alastair Graham

During recent years there has been a very great advance in our knowledge of the minute structure and function of the various regions and glands of the alimentary canal of the prosobranch and pulmonate gastropods, without any corresponding increase in our understanding of the opisthobranch and, in particular, of the nudibranch gut. That the emphasis should be laid on the streptoneurous and the land-living forms is obviously due to their abundance and to the fact that they include almost all the familiar types of gastropod mollusc, but it is disappointing that, at the moment of writing, there exists only one account of the histology and function of the digestive system of either a dorid or an æolid—to confine attention to the two main types of nudibranch molluscs which occur in British waters—that of Millott (1937b). This is perhaps more noticeable when it is recalled that the nudibranchs have specialised along distinctly unusual lines, many of which are intimately associated with the food and feeding habits which the animals have adopted. The æolids, it is true, have attracted a lively interest in connexion with their possession of nematocysts, but the majority of investigators have apparently been content to trace these into the cnidosacs without concerning themselves over the other constituents of the animal's food.


1937 ◽  
Vol 59 (1) ◽  
pp. 119-164 ◽  
Author(s):  
Vera Fretter

The work described in this paper was carried out in the Department of Zoology of Birkbeck College, University of London, and at the Marine Laboratories at Plymouth and Port Erin. I wish to acknowledge my indebtedness to the University of London for the use of their table at Plymouth, to Birkbeck College for a grant of £5 towards the illustrations, and, in particular, I would express my gratitude to Mr Graham, under whose direction the work was carried out, for his continued kindness and help.The specimens of Lepidochitona cinereus which were used for the investigation were collected at Bangor, Plymouth and Port Erin, and also obtained from Cullercoats. Most of the material from Plymouth and one specimen from Cullercoats was infected with the Haplosporidian parasite Haplosporidium chitonis (Debaisieux, 1920) and was therefore unreliable for histological and physiological work. Specimens of Acanthochitona crinitus were collected at Plymouth, and showed no sign of infection with Haplosporidium chitonis; a few, however, were slightly parasitised with another Sporozoan. The Californian species Ischnochiton magdalenensis and Cryptochiton stelleri were obtained from Turtox General Biological Supply House, Chicago. Specimens of these species were fixed in formalin, which proved to be a poor fixative for histological work.


Parasitology ◽  
1934 ◽  
Vol 26 (2) ◽  
pp. 176-248 ◽  
Author(s):  
G. S. Graham-Smith

A detailed description of the musculature in the different regions of the alimentary canal of Calliphora erythrocephala is given, and an account of the structure and function of the crop, proventriculus, ducts of the Malpighian tubes, rectal valve and rectal papillae. It has been shown by dissections and experiments that a system of channels exists in the rectal papillae through which the body fluid probably circulates, and it is suggested that the very large cells may have functions resembling those of liver cells.


2019 ◽  
Author(s):  
Genevieve C. K. Wilson ◽  
Ada Buvoli ◽  
Massimo Buvoli ◽  
Kathleen C. Woulfe ◽  
Lori A. Walker ◽  
...  

AbstractIntroductionMore than 400 mutations in β-myosin, a slow myosin motor, can cause both cardiac and skeletal myopathy in humans. A small subset of these mutations, mostly located in the myosin rod, leads to a progressive skeletal muscle disease known as Laing distal myopathy (MPD1). While this disease has previously been studied using a variety of systems, it has never been studied in the mammalian muscle environment. Here, we describe a mouse model for the MPD1-causing mutation R1500P to elucidate disease pathogenesis and to act as a future platform for testing therapeutic interventions.MethodsBecause mice have very few slow skeletal muscles compared to humans, we generated mice expressing the β-myosin R1500P mutation or WT β-myosin in fast skeletal muscle fibers and determined the structural and functional consequences of the R1500P mutation.ResultsThe mutant R1500P myosin affects both muscle histological structure and function and the mice exhibit a number of the histological hallmarks that are often identified in patients with MPD1. Furthermore, R1500P mice show decreased muscle strength and endurance, as well as ultrastructural abnormalities in the SR & t-tubules. Somewhat surprisingly because of its location in the rod, the R1500P mutation weakens acto-myosin binding by affecting cross-bridge detachment rate.ConclusionsWhile each group of MPD1-causing mutations most likely operates through distinct mechanisms, our model provides new insight into how a mutation in the rod domain impacts muscle structure and function and leads to disease.


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