The practice of medicine / by M. Charteris.

  • Charteris, M. (Matthew), 1840-1897.
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: The practice of medicine / by M. Charteris. Source: Wellcome Collection.

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    by degeneration ending in atrophy of the whole nervous tract leading from the cerebrum to the peripheral termina- tion. This is the so-called Secondary Degeneration of the cord. In muscular tissue the wasting is almost as constant. Over-work from undue mental activity may produce degenerative diseases of the nerve centres, and excessive sexual indulgence may induce atrophy of testicles and ovaries. HYPEREMIA This means an excess of blood, and may be either arterial or active hyperemia, or venous or passive hypersemia. Arterial hyperemia is due to the relaxation of the walls of the arteries and consequent enlargement of the vessels, or it may depend on increased flow of blood through the ordinary channels being interrupted, and is then known as Collateral Hyperemia. Examples of Direct Arterial Hyperemia are seen in the result of a blow, or from heat, or the reaction from intense cold; or it may be indirect through the vaso- motor nerves being diseased and losing their contractile curb on the vessels. Examples of Collateral hyperemia are observed when an embolus blocks up an artery, or when disease obstructs the chief arterial sources of an organ and leads to peripheral channels becoming hypersemic, as in cirrhosis of the liver, granular kidney, and sclerosis of the spinal cord. The symptoms of acute hypersemia are redness, increase of temperature at the part, with swelling through dis- tension of the vessels, but not by exudation, which is characteristic of inflammation. There is also usually a sensation of heat in the part, or itching. Passive hypersemia may be due to feeble circula- tion or obstruction in the veins. The action of the heart may be feeble—so feeble that there is not sufficient impetus to send the blood forward on its return current to the heart. In the erect posture