A text-book of pathology / by Alfred Stengel.

Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of pathology / by Alfred Stengel. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    IRlectrical Influences.—Electrical discharges may cause burns or similar lesions of the surface, and frequently cause intense siiock. Disturbances of the central nervous system of various sorts may occur immediately or some time after the exposure. Doubt- less there are distinct organic changes in the nervous tissues, but these have not been determined. Gross injuries of organs, such as rupture and degenerative changes, may be occasioned. POISONS. Definition.—The term poison may be applied to substances which when introduced into the living organism disturb the struct- ure or functional activity. The Action of Poisons in General.—Gaseous poisons act mainly upon the respiratory mucous membranes with which they come in contact, or after absorption into the blood disorganize this fluid or lead to disturbances of the nervous system. Liquid poi- sons are generally absorbed through the gastro-intestinal mucous membrane, but may be received directly into the tissues by injec- tion under the skin. They are rarely absorbed through the skin. Solid poisons must in all cases first be dissolved, and are then ab- sorbed like the liquid poisons. They may by their strong attrac- tion for water absorb the latter directly from the tissues, and by this process alone may bring about important changes. The lesions due to a poison may be entirely local, as in the case of certain corrosives or caustics; in other cases the point of entrance is unaffected, the pathologic manifestations being en- tirely due to the changes in different parts of the body, or to ner- vous disturbances resulting from the circulation of the poison in the blood. The fate of poisons after ingestion is very different in dif- fei'ent cases. Some poisons circulate with the blood and are eliminated unchanged. Others may suffer chemical change within the stomach or other cavities of the body before absorption, and may be either completely neutralized, or may be converted into forms which are subsequently slowly absorbed. After absorption into the blood other chemical reactions may occur, and the poison may be more or less neutralized, the system then suffering either from the resulting c(Mn]iounds or from the changed conditions of the blood. Active destruction of the poison may occur in the blood or in the various organs. In these processes, however, the glandular organs may suffer seriously, various forms of degenera- tion or necrosis resulting. The effect of poisons depends upon the dose as well as upon the nature of the substance, and also upon the individual. The repeated ingestion of certain poisons, such as arsenic or o]iium, may generate a considerable degree of immunity or tolerance.