Outlines of surgery and surgical pathology : including the diagnosis and treatment of obscure and urgent cases and the surgical anatomy of some important structures and regions / by F. Le Gros Clark.

  • Clark, Frederick Le Gros, 1811-1892.
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of surgery and surgical pathology : including the diagnosis and treatment of obscure and urgent cases and the surgical anatomy of some important structures and regions / by F. Le Gros Clark. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    entirely secondary, and dependent on the antecedent loss of balance in the capillary network, the arteries and veins holding the relation of intermediate conduits between them and the heart. In health, the due balance of waste and supply is preserved ; yet the operation of efficient causes may, without constituting disease, induce an extraordinary or diminished supply of blood to a part, and the corresponding consequence of excess in growth or the reverse ; as in muscle when much taxed or disused. But there are other ways in which the balance may be suspended or lost in which a large quantity of blood may be accumulated at any given point: this is u Hyperaemia.” Such hyperaemia may depend on two distinct mechanical causes —one in which the accumulation is the consequence of some obstruction to the return of the blood through the veins towards the heart; the other in which it is conveyed to a part in in- creased quantity through the arteries. These two conditions are severally denominated passive and active hyperatma. Passive Hyperaemia, or Congestion, is the effect of mechanical obstruction, as where a vein is compressed or plugged. The consequence of such venous obstruction is distension of the capillaries, and, if continued, infiltration of tissues from excessive exudation of liquor sanguinis. Thus cedema or local dropsy, ascites or abdominal dropsy, and anasarca or general dropsy, are produced. In this filtering process through the porous vessels tbe nutritive quality of the liquor sanguinis is modified by changes in the proportion of albumen and salts ; so that, although the quantity of blood actually present in a part so affected is unnaturally large, it is blood despoiled of its nutritive and stimulating properties, and therefore valueless for growth. Thus, congestion is an atrophic condition ; and its effect is the same as where there is simply a deficient supply of nutrient blood, without detention ; as proved by the feebleness of muscular tissue, which is the seat of such congestion, the occurrence of ulcers in varicose limbs, &c. As, in passive hyperaemia, there is retention of deteriorated blood, so, in Active Hyperaemia, there is an increased supply