THE MORPHOLOGY OF THE NEMATODE RADOPHOLUS GRACILIS (DE MAN, 1880) HIRSCHMANN, 1955, PARASITIC IN ROOTS OF WILD RICE, ZIZANIA AQUATICA L.

1957 ◽  
Vol 35 (1) ◽  
pp. 75-92 ◽  
Author(s):  
K. C. Sanwal
Keyword(s):  
Vas Deferens ◽  
Neutral Red ◽  
Silver Impregnation ◽  
Nerve Ring ◽  
The Body ◽  
Impregnation Method ◽  
Sense Organs ◽  
Low Oxygen ◽  
Zizania Aquatica ◽  
De Man

The anatomy of Radopholus gracilis is described, the description being based chiefly on the study of living specimens and intravital staining with methylene blue and neutral red. Cajal's silver impregnation method and Golgi's bichromate silver method, both with slight modifications, prove useful.Cuticle striated with four longitudinal incisures; 16–18 muscle cells in anterior region; head supported by six-ridged cuticular framework with six lips and 16 sense organs; excretory system with anterior and posterior canals opening into an ampulla, all on left side of the body, and a cuticular terminal duct; ovaries opposed and outstretched; vas deferens differentiated into three regions and no central rachis in the gonads; nerve ring associated with a group of 7, 13, and 27 cells on dorsal, ventral, and lateral sides respectively; phasmid nerve supply from lateral nerves; 'hemizouid' organ present. The nematodes appear to be adapted to an aquatic environment and seem to be unaffected by low temperatures and low oxygen content in their habitat.

scholarly journals TEMPERATURE CHARACTERISTICS FOR PULSATION FREQUENCY IN GONIONEMUS

1928 ◽  
Vol 11 (5) ◽  
pp. 547-562 ◽  
Author(s):  
Ernst Wolf
Keyword(s):  
Critical Temperature ◽  
Functional Unit ◽  
Temperature Characteristic ◽  
Nerve Ring ◽  
Pulsation Frequency ◽  
Sense Organs ◽  
Critical Temperatures ◽  
Temperature Characteristics ◽  
System A ◽  
Definite Temperature

The frequency of contraction of the bell of Gonionemus was studied in relation to temperature, with intact animals and also where different operations were made on the nervous system. A number of values of µ are found for intact animals namely 8,100±, 10,500±, 32,000± and 22,500±, with critical temperatures at 9.6°, 12.3°, and 14.0°. Four different classes of operations were used: (1) Animals where the nerve ring was cut on two opposite sides of the bell; the µ values found are 10,500± and 21,300±, with a critical temperature at 13.4°. (2) Animals with four cuts through the nerve ring gave µ = 10,600 ± and µ = 21,000, with a critical temperature at 13.1°. (3) In animals where the bell was cut in half the temperature characteristic was found to be 16,900. And finally (4) in the animals where the nerve ring was totally removed µ values of 8,100, 16,000±, and 29,000 were found, with critical temperatures at 15.0° and 9.4°. These results are discussed from the standpoint of the theory which supposes that definite "temperature characteristics" may be associated with the functional activity of particular elements in a complex functional unit, and that these elements may be separately studied and identified by suitable experimental procedures involving the magnitudes of the respective temperature characteristics and the locations of associated critical temperatures. The swimming bell of medusæ with its marginal sense organs permits a fairly direct approach to such questions. It is found that even slight injuries to the marginal nerve ring, for example, produce specific modifications in the temperature relations which are different from those appearing when the organism is cut in half.

A Rapid Silver Impregnation Method for Nervous Tissue: A Modified Protargol-Peroxide Technic

1979 ◽  
Vol 54 (2) ◽  
pp. 97-100 ◽  
Author(s):  
G. P. Loots ◽  
J. M. Loots ◽  
J. M. M. Brown ◽  
J. L. Schoeman
Keyword(s):  
Nervous Tissue ◽  
Silver Impregnation ◽  
Impregnation Method

A rapid silver impregnation method for demonstrating amyelinate nerve fibres

1960 ◽  
Vol 20 (3) ◽  
pp. 423-426 ◽  
Author(s):  
B. Csillik
Keyword(s):  
Silver Impregnation ◽  
Impregnation Method ◽  
Nerve Fibres

Morphological descriptions of the egg and larval stages of Trichuris suis Schrank, 1788

Parasitology ◽  
1973 ◽  
Vol 67 (3) ◽  
pp. 263-278 ◽  
Author(s):  
R. J. S. Beer
Keyword(s):  
Reproductive System ◽  
Intestinal Tract ◽  
Vas Deferens ◽  
Ejaculatory Duct ◽  
The Body ◽  
Vitelline Membrane ◽  
Initial Development ◽  
Larval Stages ◽  
Trichuris Suis ◽  
System L

The egg and larval stages of Trichuris suis can be briefly characterized as follows: The egg: barrel shaped, possesses a thick shell consisting of three thick outer layers and an inner thin vitelline membrane, is operculate at each end and is unsegmented and unfertilized when freshly deposited. L. 1 within the egg: presence of an oral spear, a poorly denned oesophagus and an intestinal tract consisting of undifferentiated granulated material. L. 1 within the host: initial differentiation of an oesophagus, cell body, intestine and rectum. L. 2: further differentiation of the body organs and the appearance of the rudiments of the reproductive system. L. 3: initial development of reproductive system and development of a cloaca in the male thus distinguishing the sexes. L. 4: differentiation of reproductive system into vagina, uterus, oviduct and ovary in the female, and testis, vas deferens, ejaculatory duct, spicule and spicular muscle, sheath and tube in the male. L. 5 or adult stage: completed development of the sexual organs including formation of the vulval orifice and eggs in the female and seminal vesicle in the male.

SIMPLIFIED SILVER IMPREGNATION METHOD FOR MICRUCLIA

1952 ◽  
Vol 5 (3) ◽  
pp. 181-187
Author(s):  
Kenzi Yano
Keyword(s):  
Silver Impregnation ◽  
Impregnation Method

scholarly journals The Hypoxic Testicle: Physiology and Pathophysiology

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Juan G. Reyes ◽  
Jorge G. Farias ◽  
Sebastián Henríquez-Olavarrieta ◽  
Eva Madrid ◽  
Mario Parraga ◽  
...  
Keyword(s):  
Germ Cell ◽  
Testicular Torsion ◽  
Oxygen Supply ◽  
Cell Function ◽  
Cell Damage ◽  
The Body ◽  
Body Core Temperature ◽  
Seminiferous Tubules ◽  
Low Oxygen ◽  
Complex Biological Process

Mammalian spermatogenesis is a complex biological process occurring in the seminiferous tubules in the testis. This process represents a delicate balance between cell proliferation, differentiation, and apoptosis. In most mammals, the testicles are kept in the scrotum 2 to 7°C below body core temperature, and the spermatogenic process proceeds with a blood and oxygen supply that is fairly independent of changes in other vascular beds in the body. Despite this apparently well-controlled local environment, pathologies such as varicocele or testicular torsion and environmental exposure to low oxygen (hypoxia) can result in changes in blood flow, nutrients, and oxygen supply along with an increased local temperature that may induce adverse effects on Leydig cell function and spermatogenesis. These conditions may lead to male subfertility or infertility. Our literature analyses and our own results suggest that conditions such as germ cell apoptosis and DNA damage are common features in hypoxia and varicocele and testicular torsion. Furthermore, oxidative damage seems to be present in these conditions during the initiation stages of germ cell damage and apoptosis. Other mechanisms like membrane-bound metalloproteinases and phospholipase A2 activation could also be part of the pathophysiological consequences of testicular hypoxia.

scholarly journals The Function of the Gills of Mayfly Nymphs from Different Habitats

1939 ◽  
Vol 16 (3) ◽  
pp. 363-373 ◽  
Author(s):  
C. A. WINGFIELD
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Content ◽  
The Body ◽  
Gaseous Exchange ◽  
Low Oxygen ◽  
Respiratory Mechanism ◽  
Tracheal Gills ◽  
Cloeon Dipterum ◽  
Gill Function ◽  
Oxygen Concentrations

1. The oxygen consumption of normal and gill-less nymphs of the mayflies Baetis sp., Cloeon dipterum and Ephemera vulgata has been measured at various oxygen concentrations. 2. It has been found that over the complete range of oxygen concentrations studied, the tracheal gills do not aid oxygen consumption in Baetis sp. In Cloeon dipterum, at all oxygen concentrations tested, no gaseous exchange takes place through the gills; at low oxygen concentrations, however, the gills function as an accessory respiratory mechanism in ventilating the respiratory surface of the body and so aid oxygen consumption. In Ephemera Vulgata the gills aid oxygen consumption even at high oxygen concentrations. In this species the gills may function both as true respiratory organs and as a ventilating mechanism. 3. It is shown that the differences in gill function can be related to the oxygen content of the habitat of each species.

scholarly journals Asymmetrical morphology and growth of the hermit crab Pagurus filholi (Decapoda, Anomura, Paguridae) reared in non-dextral shell conditions

Crustaceana ◽  
2014 ◽  
Vol 87 (4) ◽  
pp. 476-488 ◽  
Author(s):  
Michio Imafuku ◽  
Hisakazu Ikeda
Keyword(s):  
Hermit Crab ◽  
The Body ◽  
Body Parts ◽  
Pagurus Filholi ◽  
Control Body ◽  
The Right ◽  
De Man ◽  
Major Cheliped

The body of a hermit crab shows asymmetrical morphology, which may be related to utilization of the dextral shell. To examine the effect of the shell, we reared Pagurus filholi (De Man, 1887) from the glaucothoe stage to full-sized adults, in a sinistral shell, in a straight tusk shell, without a shell, and in a normal dextral shell as a control. Body parts that show the most conspicuous asymmetry, uropods, pleopods and chelipeds, were checked at the time of the shedding of exuviae during rearing. No inversion of laterality on these characters was observed. However, in crabs subjected to conditions other than a dextral shell, the otherwise rather short right uropod became somewhat extended, and in those reared in sinistral shells, the right major cheliped was more enlarged.

The Activity of Lateral-Line Efferent Neurones in Stationary and Swimming Dogfish

1972 ◽  
Vol 57 (2) ◽  
pp. 435-448 ◽  
Author(s):  
B. L. ROBERTS ◽  
I. J. RUSSELL
Keyword(s):  
Lateral Line ◽  
Body Movement ◽  
Cranial Nerves ◽  
Regulatory System ◽  
The Body ◽  
Muscle Fibres ◽  
Sense Organs ◽  
Efferent System ◽  
Natural Stimulation ◽  
Stimulation Of

1. The activity of efferent neurones innervating lateral-line organs on the body of dogfish was followed by recording from filaments of cranial nerve X in 41 decerebrate preparations. 2. The efferent nerves were not spontaneously active. 3. Tactile stimulation to the head and body, vestibular stimulation and noxious chemical stimulation were followed by activity of the efferent nerves. 4. In contrast, natural stimulation of lateral-line organs (water jets) did not reflexly evoke discharges from the efferent fibres. 5. Reflex efferent responses were still obtained to mechanical stimulation even after the lateral-line organs had been denervated. 6. Electrical stimulation of cranial nerves innervating lateral-lines organs was followed by reflex activity of the efferent fibres. But similar stimuli applied to other cranial nerves were equally effective in exciting the efferent system. 7. Vigorous movements of the fish, involving the white musculature, were preceded and accompanied by activity of the efferent fibres which persisted as long as the white muscle fibres were contracting. 8. Rhythmical swimming movements were accompanied by a few impulses in the efferent fibres grouped in bursts at the same frequency as the swimming movements. 9. It is concluded that the efferent neurones cannot contribute to a feedback regulatory system because they are not excited by natural stimulation of the lateral-line sense organs. The close correlation found between efferent activity and body movement suggests that the efferent system might operate in a protective manner to prevent the sense organs from being over-stimulated when the fish makes vigorous movements.

scholarly journals Preliminary Note on the Structure and Affinities of Phoronis

1897 ◽  
Vol 21 ◽  
pp. 59-71 ◽  
Author(s):  
Arthur T. Masterman
Keyword(s):  
Distinct Species ◽  
Systematic Position ◽  
Nerve Ring ◽  
The Body ◽  
Serial Sections ◽  
Preliminary Note ◽  
Mouth Region ◽  
Careful Comparison ◽  
A New Species ◽  
Different Parts

In spite of the great amount of attention which has been bestowed upon this group by many workers, it must still be said that our knowledge of its systematic position is very meagre and uncertain, and that there are points in its anatomy which require elucidation. Through the kindness of Professor M‘Intosh I have been enabled to examine some specimens of P. australis, and also a Phoronis, which appears to be a new species. I reserve a detailed account of my results for later publication, and here only refer very briefly to leading points. I may mention that Professor M‘Intosh has also allowed me the inspection of his serial sections of P. buskii. M‘Intosh, and after a careful comparison I have not the slightest doubt that this is a distinct species from P. australis—it has been usual to regard the distinction between these two forms as not of specific value.Divisions of the Body.—It is usual, in describing the structure of Phoronis, to refer to two different parts of the body which lie before and behind the septum respectively. I propose, for reasons shown later, to emphasise the division of the body into—(1) The epistome, lying dorsally to the mouth, and having very definite, though somewhat involved, relationship to the next part; (2) the tentacular region, which I prefer to call the collar, consisting of a ring round the mouth region, the oral part being produced into two arms or processes which bear tentacles and are coiled, and the aboral end being limited superficially by the nerve ring and fundamentally by the so-called septum; (3) the trunk, including all the region behind the septum.

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