The Alimentary Canal, its Appendages, Salivary Glands and the Nervous System of the adult Female Lac Insect, Laccifer lacca, Kerr (Coccidae)

1934 ◽  
Vol 25 (4) ◽  
pp. 541-550 ◽  
Author(s):  
P. S. Negi

SummaryOwing to the deposition of resin, the females assume two shapes, one somewhat circular in which the mouth-parts are situated ventrally about the middle of the body, and the other pyriform, in which the mouth-parts are situated at the extreme anterior end. In the former type of females the mouth-parts are posteriorly directed and in the latter anteriorly. The rostrum lies outside the body cavity between the anterior pair of oral lobes. The rostralis opens into the pharynx which lies in the tentorium. The oesophagus is elongated and passes into the colo-rectum to be succeeded by the convoluted ventriculus. The ventriculus on leaving the colo-rectum leads into the intestine, which is marked into the mid and hind intestine by the junction of the ampulla of the Malpighian tubes. The intestine after forming a loop round the greater part of the colo-rectum re-enters it close to the point of its commencement from it and continues closely attached to the outer side of the ventriculus from its distal to its proximal end; after this it comes out of the colo-rectum and runs alongside it to open into it near the anterior third of its length. The convolutions inside the colo-rectum are comprised of the ventriculus and the part of the hind intestine running outer to it. The “colon caecum” is absent. The colo-rectum opens at the anus situated at the posterior end of the insect and is divided into colon and rectum by the opening of the intestine into it.The salivary glands consist of two branches of ovoid and spherical bodies. The common duct of the salivary gland of each side runs close to the ventral ganglion and joins the opposite duct to form the terminal duct near its anterior end, which then opens into the pharynx.The nervous system consists of a bilobed cerebral ganglion which lies anteriorly to the mouth-parts in females in which the tentorium is directed posteriorly, and either laterally or ventrally to it in females in which the tentorium is directed anteriorly and lies at the extreme anterior end. The cerebral ganglion is joined by a pair of connectives to the ventral ganglion, which lies dorsal to the tentorium in females in which it is directed posteriorly, and posterior to the tentorium in which it is directed anteriorly and lies at the extreme anterior end. The ventral ganglion is followed by the nerve chord, which varies in length in either type of female. The main nerves arising from the central nervous system are described.

Author(s):  
F. L. Azizova ◽  
U. A. Boltaboev

The features of production factors established at the main workplaces of shoe production are considered. The materials on the results of the study of the functional state of the central nervous system of women workers of shoe production in the dynamics of the working day are presented. The level of functional state of the central nervous system was determined by the speed of visual and auditory-motor reactions, installed using the universal device chronoreflexometer. It was revealed that in the body of workers of shoe production there is an early development of inhibitory processes in the central nervous system, which is expressed in an increase in the number of errors when performing tasks on proofreading tables. It was found that the most pronounced shift s in auditory-motor responses were observed in professional groups, where higher levels of noise were registered in the workplace. The correlation analysis showed a close direct relationship between the growth of mistakes made in the market and the decrease in production. An increase in the time spent on the task indicates the occurrence and growth of production fatigue.Funding. The study had no funding.Conflict of interests. The authors declare no conflict of interests.


Author(s):  
Prithiv K R Kumar

Stem cells have the capacity to differentiate into any type of cell or organ. Stems cell originate from any part of the body, including the brain. Brain cells or rather neural stem cells have the capacitive advantage of differentiating into the central nervous system leading to the formation of neurons and glial cells. Neural stem cells should have a source by editing DNA, or by mixings chemical enzymes of iPSCs. By this method, a limitless number of neuron stem cells can be obtained. Increase in supply of NSCs help in repairing glial cells which in-turn heal the central nervous system. Generally, brain injuries cause motor and sensory deficits leading to stroke. With all trials from novel therapeutic methods to enhanced rehabilitation time, the economy and quality of life is suppressed. Only PSCs have proven effective for grafting cells into NSCs. Neurons derived from stem cells is the only challenge that limits in-vitro usage in the near future.


In the study of the phenomena of anaphylaxis there are certain points on which some measure of agreement seems to have been attained. In the case of anaphylaxis to soluble proteins, with which alone we are directly concerned in this paper, the majority of investigators probably accept the view that the condition is due to the formation of an antibody of the precipitin type. Concerning the method, however, by which the presence of this antibody causes the specific sensitiveness, the means by which its interaction with the antibody produces the anaphylactic shock, there is a wide divergence of conception. Two main currents of speculation can be discerned. One view, historically rather the earlier, and first put forward by Besredka (1) attributes the anaphylactic condition to the location of the antibody in the body cells. There is not complete unanimity among adherents of this view as to the nature of the antibody concerned, or as to the class of cells containing it which are primarily affected in the anaphylactic shock. Besredka (2) himself has apparently not accepted the identification of the anaphylactic antibody with a precipitin, but regards it as belonging to a special class (sensibilisine). He also regards the cells of the central nervous system as those primarily involved in the anaphylactic shock in the guinea-pig. Others, including one of us (3), have found no adequate reason for rejecting the strong evidence in favour of the precipitin nature of the anaphylactic antibody, produced by Doerr and Russ (4), Weil (5), and others, and have accepted and confirmed the description of the rapid anaphylactic death in the guinea-pig as due to a direct stimulation of the plain-muscle fibres surrounding the bronchioles, causing valve-like obstruction of the lumen, and leading to asphyxia, with the characteristic fixed distension of the lungs, as first described by Auer and Lewis (6), and almost simultaneously by Biedl and Kraus (7). But the fundamental conception of anaphylaxis as due to cellular location of an antibody, and of the reaction as due to the union of antigen and antibody taking place in the protoplasm, is common to a number of workers who thus differ on details.


1957 ◽  
Vol 34 (3) ◽  
pp. 306-333
Author(s):  
G. M. HUGHES

I. The effects of limb amputation and the cutting of commissures on the movements of the cockroach Blatta orientalis have been investigated with the aid of cinematography. Detailed analyses of changes in posture and rhythm of leg movements are given. 2. It is shown that quite marked changes occur following the amputation of a single leg or the cutting of a single commissure between the thoracic ganglia. 3. Changes following the amputation of a single leg are immediate and are such that the support normally provided by the missing leg is taken over by the two remaining legs on that side. Compensatory movements are also found in the contralateral legs. 4. When two legs of opposite sides are amputated it has been confirmed that the diagonal sequence tends to be adopted, but this is not invariably true. Besides alterations in the rhythm which this may involve, there are again adaptive modifications in the movements of the limbs with respect to the body. 5. When both comrnissures between the meso- and metathoracic ganglia are cut, the hind pair of legs fall out of rhythm with the other four legs. The observations on the effects of cutting commissures stress the importance of intersegmental pathways in co-ordination. 6. It is shown that all modifications following the amputation of legs may be related to the altered mechanical conditions. Some of the important factors involved in normal co-ordination are discussed, and it is suggested that the altered movements would be produced by the operation of these factors under the new conditions. It is concluded that the sensory inflow to the central nervous system is of major importance in the co-ordination of normal movement.


1998 ◽  
Vol 84 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Maria Laura Del Basso De Caro ◽  
Antonella Siciliano ◽  
Paolo Cappabianca ◽  
Alessandra Alfieri ◽  
Enrico de Divitiis

Paragangliomas are usually benign tumors which can be found in many sites of the body, from the base of the skull down to the pelvic floor. In the central nervous system the sellar region is very rarely involved; only three well studied cases have been reported to date. We present the cytological, histological, histochemical, immunocytochemical and ultrastructural features of an intrasellar and suprasellar paraganglioma in an 84-year-old man.


PEDIATRICS ◽  
1973 ◽  
Vol 52 (3) ◽  
pp. 449-451
Author(s):  
Barry H. Rumack

The increased incidence of poisoning by overdoses of commonly used drugs with anticholinergic properties (Table I) and the general lack of knowledge concerning a specific treatment for these poisons warrants a summary of the problem at this time. Some plants containing anticholinergic alkaloids are also included in this group as they may also be taken intentionally or accidentally. Drugs with anticholinergic properties primanly antagonize acetylcholine competitively at the neuroreceptor site. Cardiac muscle, exocrine glands, and smooth muscle are most markedly affected.1 Action of the inhibitors is overcome by increasing the level of acetylcholine naturally generated in the body through inhibiting the enzyme (choline esterase) which normally prevents accumulation of excess acetylcholine. It does this by hydrolyzing that compound to inactive acetic acid and choline. Agents which inhibit this enzyme, so that acetylcholine accumulates at the neuroreceptor sites, are called anticholine esterases. Physostigmine, one of the anticholine esterases which is a tertiary amine, crosses into the central nervous system and can reverse both central and peripheral anticholinergic actions2. Neostigmine and pyridostigmine are also anticholine esterases but they are quaternary amines and are capable of acting only outside the central nervous system because of solubility and ionization characteristics. The anticholinergic syndrome has both central and peripheral signs and symptoms. Central toxic effects include anxiety, delirium, disorientation, hallucinations, hyperactivity, and seizures.2 Severe poisoning may produce coma, medullary paralysis, and death. Peripheral taxicity is characterized by tachycardia, hyperpyrexia, mydriasis, vasodilatation, urinary retention, diminution of gastrointestinal motility, decrease of secretion in salivary and sweat glands, and loss of secretions in the pharynx, bronchi, and nasal passages.


1948 ◽  
Vol s3-89 (5) ◽  
pp. 1-45
Author(s):  
J.A. C. NICOL

1. A description is given of the main features of the central nervous system of Myxicola infundibulum Rénier. 2. The nerve-cord is double in the first four thoracic segments and single posteriorly. It shows segmental swellings but is not ganglionated in the usual sense in that nerve-cell accumulations are not related directly to such swellings of the cord. 3. A very large axon lies within the dorsal portion of the nerve-cord and extends from the supra-oesophageal ganglia to the posterior end of the animal. It is small in the head ganglia where it passes transversely across the mid-line, increases in diameter in the oesophageal connectives, and expands to very large size, up to 1 mm., in the posterior thorax and anterior abdomen, and gradually tapers off to about 100µ in the posterior body. It shows segmental swellings corresponding to those of the nerve-cord in each segment. It occupies about 27 per cent, of the volume of the central nervous system and 0.3 per cent, of the volume of the animal. The diameter of the fibre increases during contraction of the worm. 4. The giant fibre is a continuous structure throughout its length, without internal dividing membranes or septa. Usually a branch of the giant fibre lies in each half of the nerve-cord in the anterior thoracic segments and these several branches are continuous with one another longitudinally and transversely. 5. The giant fibre is connected with nerve-cells along its entire course; it arises from a pair of cells in the supra-oesophageal ganglia, and receives the processes of many nerve-cells in each segment. There is no difference between the nerve-cells of the giant fibre and the other nerve-cells of the cord. 6. A distinct fibrous sheath invests the giant fibre. A slight concentration of lipoid can be revealed in this sheath by the use of Sudan black. 7. About eight peripheral branches arise from the giant fibre in each segment. They have a complex course in the nerve-cord where they anastomose with one another and receive the processes of nerve-cells. Peripherally, they are distributed to the longitudinal musculature. 8. Specimens surviving 16 days following section of the nerve-cord in the thorax have shown that the giant fibre does not degenerate in front of or behind a cut, thus confirming that it is a multicellular structure connected to nerve-cells in the thorax and abdomen. 9. It is concluded that the giant fibre of M. infundibulum is a large syncytial structure, extending throughout the entire central nervous system and the body-wall of the animal. 10. The giant fibre system of M. aesthetica resembles that of M. infundibulum. 11. Some implications of the possession of such a giant axon are discussed. It is suggested that its size, structure, and simplicity lead to rapid conduction and thus effect a considerable saving of reaction time, of considerable value to the species when considered in the light of the quick contraction which it mediates. The adoption of a sedentary mode of existence has permitted this portion of the central nervous system to become developed at the expense of other elements concerned with errant habits.


Bioprinting ◽  
2021 ◽  
pp. 98-118
Author(s):  
Kenneth Douglas

Abstract: This chapter recounts bioprinting studies of skin, bone, skeletal muscle, and neuromuscular junctions. The chapter begins with a study of bioprinted skin designed to enable the creation of skin with a uniform pigmentation. The chapter relates two very different approaches to bioprinted bone: a synthetic bone called hyperelastic bone and a strategy that prints cartilage precursors to bone and then induces the conversion of the cartilage to bone by judicious choice of bioinks. Muscles move bone, and the chapter discusses an investigation of bioprinted skeletal muscle. Finally, the chapter considers an attempt to bioprint a neuromuscular junction, a synapse—a minute gap—of about 20 billionths of a meter between a motor neuron and the cell membrane of a skeletal muscle cell. A motor neuron is a nerve in the central nervous system that sends signals to the muscles of the body.


2018 ◽  
Vol 2 ◽  
pp. 239821281881749 ◽  
Author(s):  
Arthur Butt ◽  
Alexei Verkhratsky

The name neuroglia is generally translated as nerve glue. In the recent past, this has been used to describe passive structural cells. Presently, this view has been challenged and the true dynamic and multifunctional nature of neuroglia is beginning to be appreciated. In the central nervous system, the main kinds of neuroglia are astrocytes (the primary homeostatic cells that ensure synaptic transmission), oligodendrocytes (which form the myelin that ensures rapid electrical transmission) and microglia (the main immune cells). In the peripheral nervous system, neuroglia comprise Schwann cells, satellite glia and enteric glia. These functionally diverse and specialised cells are fundamental to function at the molecular, cellular, tissue and system levels. Without nerve glue, the body cannot function and the future will begin to unlock their importance in higher cognitive functions that set humans apart from other animals and their true potential as therapeutic targets in neurodegenerative and other diseases.


2020 ◽  
Vol 13 (9) ◽  
pp. e235412
Author(s):  
Jesse Mooneyham ◽  
Cesar Gentille ◽  
Andrea Barbieri ◽  
Shilpan Shah

A 33-year-old woman presented to the emergency room with severe headaches. A CT scan of the head revealed two brain lesions with associated vasogenic oedema. Diagnostic resection of one of the lesions followed by pathological analysis revealed grade III lymphomatoid granulomatosis (LYG). Staging investigations elsewhere in the body were negative, isolating this case of LYG to the central nervous system, an atypical presentation. After the resection, she was treated with single-agent rituximab 375 mg/m2. The follow-up MRI demonstrated the resolution of brain lesions and no progression of the disease.


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