NEUROPATHOLOGY , the See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

The See also:

• MODERN

We may regard the neurone as a complex cell, and the nervous system as a community of neurones arranged in systems and groups having special functions. Like all cells, the neurone nourishes itself and is not nourished; certainly it depends for its development, life and functional activity upon a suitable environment, but it must also possess an inherent vital See also:

• ENERGY (from the Gr. ivipyela; iv, in, ipyov, work)

Abnormal conditions of the blood and See also:

• LYMPH

Clotting of the blood in the See also:

• VEINS

All the See also:

• SERIES (a Latin word from serere, to join)

The coma is very possibly due to the saturation of the See also:

• SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

The syphilitic poison is the most important factor in the production of two progressive degenerations of the nervous system—one affecting especially the afferent conducting tracts of the spinal cord, namely, locomotor ataxy, and the other affecting especially the frontal and central convolutions of the cerebral hemispheres, namely, general paralysis of the insane. A striking instance of the selective action of the syphilitic poison is shown in the fact that only in persons affected with acquired or inherited syphilis is a symptom known as See also:

• ARGYLL, EARLS AND DUKES OF

Certain hitherto obdiseases scure diseases in which the nervous system is profoundly of affected are now explained by the invasion of the tissues of the body by these lowly organisms, for example, fig. I). The See also:

• DISCOVERY

(2) Negri bodies are the result of See also:

• INTRA

The tissue changes are the same whether we system. examine the primary seat of infection, papular eruptions on the mucous membrane or the skin, or the lymphatic glands. When the nervous system is affected a local or general chronic meningo-encephalitis is set up, characterized by a meningeal and 1 perivascular infiltration with lymphocytes and plasma cells, occasioned by a chronic irritative process, presumably caused in the case of sleeping sickness by the presence of See also:

• TRYPANOSOMES, or HAEMOFLAGELLATES

4 nervous Sleeping Sickness, the cause of which has been definitely system. proved to be the Trypanosoma gambiense (see Plate II. 8 See also:

• PATHOLOGY (from Gr. raBos, suffering)

I) which are the essential cause of the disease. It has been remarked that the normal cerebro-spinal fluid is devoid of proteins, but in the various forms of disease above described as containing cells in the centrifuged deposit, there is also in the fluid an appreciable amount of proteins. If pathological cerebro-spinal fluid be added to an equal quantity of saturated See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

We can understand that it may be a See also:

• CHANCE (through the O. Fr. cheance, from the Late Lat. cadentia, things happening, from cadere, to fall out, happen; cf. " case ")

In not more than to % is See also:

• ALCOHOL

A certain amount of improvement may occur when See also:

• TOTAL

A distinctive feature, however, was the pigmentation of the skin and the severity of the nervous symptoms. A disease which is common in the See also:

• EAST
• EAST, ALFRED (1849- )

In See also:

• ILLUSTRATION

Consciously and unconsciously, a continuous stream of impulses is pouring into the nervous system from without by the sensory channels, which are the avenues of experience and intelligence, and our somatic and psychical life depends upon the existence of such stimuli. The nervous system in the form of systems, groups and communities of neurones, each with special functions, yet all See also:

• WOVEN

2, 3, 4 ands.—Spinal motor cells in various stages of destruction, from a case of acute alcoholic poly-vacuolation. Compare with the appearances of a normal cell, fig. 12. the limb. diseases of the female reproductive organs act as exciting causes in the production of hysteria, hystero-epilepsy, melancholia and mania; moreover, paroxysmal attacks in these diseases are more liable to occur at the menstrual period or menopause. The irritation of a carious tooth may produce spasmodic See also:

• TIC

Should, however, the wound or diseased structure become infected with micro-organisms, the disease spreads and becomes generalized likewise the symptoms. Of all the causes of infective inflammation, See also:

• MIDDLE

5 and 9). When the embolus is infective, as it frequently is in ulcerative endocarditis, its lodgment in an artery of the brain, not only blocks the vessel but leads to an infective inflammation and softening of its coats, with the formation of an aneurism. The aneurism may suddenly rupture into the substance of the brain and produce apoplexy. In fact the majority of cases of apoplexy from cerebral haemorrhage recurring in young people are due to this cause. Softening may also arise from coagulation of the blood (thrombosis) ie the arteries or veins. There are many causes which generally combine or conspire together to produce thrombosis, viz. a weak acting heart and altered conditions of the blood, and sometimes independently of vascular disease spontaneous coagulation in a vessel of the brain may occur. It is sometimes met with in the cachexia of certain grave diseases, viz. in See also:

• PHTHISIS (Gr. 49Lnns " wasting ")

Disease of the arteries of the central nervous system, occurring in a person under See also:

• FORTY

the myelin sheath and ending in an increase of the supporting neuroglia tissue at the expense of the true nervous tissue. Tumours and new growths in the central and peripheral nervous systems may be primary or secondary: the former arise in the supporting, enclosing or nutrient tissue elements; the latter are metastatic deposits from tumours originating elsewhere. Tumours may be single or multiple, the special symptoms occasioned depending ,otic Thhat. se' Deters nucleus See also:

• POST

Various forms of motor and sensory loss and disturbance of function may arise, indicating destruction or disturbance of particular regions of the central nervous system; and degenerations in certain tracts and systems of fibres arise, corresponding in histological character with those observed when a nerve fibre is separated from its cell of origin by See also:

• SECTION
• SECTION (Lat. sectio, cutting, secare, to cut)

Neuroses and psychoses have not hitherto been satisfactorily explained by definite morphological changes in the brain (Plate I., fig. 1). We know little or nothing accurately about the morbid See also:

• HISTOLOGY
• HISTOLOGY (Gr. Ler6c, web, tissue, properly the web-beam of the loom, from iQravai, to make to stand)

Conditions of dementia, primary or secondary, are associated with progressive decay and atrophy of the superficial layers of the grey matter of the cortex, and naked-eye evidence thereof is afforded by partial or general wasting of the cerebral hemispheres, accompanied with thickening of the pia-arachnoid membrane, atrophy of the convolutions, and with deepening and widening of the intervening See also:

• SULCI

Possibly new methods may enable us to show changes of structure in diseases such as epilepsy and delusional insanity, in which hitherto no naked eye or microscopical structural defects accounting for the symptoms have been certainly demonstrated. In conditions of acute mania there is usually considerable vascular engorgement. We should, however, probably be more correct in assuming that insanity (especially those forms in which there is neither amentia or dementia) is due to alterations in the quality 3 4 5 6 7 cylinder sprouting and forming a number of axis-cylinder processes, which grow into the peripheral end to form new channels of See also:

• CONDUCTION, ELECTRIC

18-22, with explanatory text. When a nerve cell See also:

• DIES, CHRISTOPH ALBERT (1755-1822)

The Marchi reaction, which has been found so useful for demonstrating degeneration of the central and peripheral nervous systems, is dependent upon the fact that the myelin sheath, after hardening in a solution of bichromate of potash, does not turn black when acted upon by osmic acid, whereas the simpler non-phosphoretted fatty product of degeneration is stained black. When the Marchi reaction of degeneration is fully developed, it has been ascertained that the nerve yields no phosphorus. The degeneration resulting from section of a nerve is termed secondary, to distinguish it from another, primary, due to slow 1 2 regeneration of medullated nerve fibres. 1, Normal medullated nerve with 5, Complete absorption of de- See also:

• NODE (Lat. nodus, a loop)

Also See also:

• GOWER
• GOWER, JOHN (d. 1408)