5 wh-questions
(составить 5 во к тексту, начинающихся с во слов) There are three structures of the kidney which are susceptible to disease: the glomeruli, the tubules and the blood vessels. However, it is rare that only one of these structures is affected; what happens to one frequently affects the others as well.
The disease in which the glomeruli are particularly involved is called glomerulo-nephritis. It may be acute or chronic, the first frequently leading to the second. It is often a sequel to such a childhood infectious disease as scarlet fever. In glomerulo-nephritis, the glomeruli become clogged with exudate and cell debris so that the blood no longer flows through them. Here a clearance test is useful; it will show that much smaller quantities of filtrate are being formed than normally. The glom eruli bei ng still open become permeable to protein and albuminu ria becomes very marked. This leads to edema.
Diseases involving the tubules are called nephroses. They are usually caused by poisons of various kinds, such as mercury, bismuth, uranium, or carbolic acid. Some degree of tubular degeneration occurs, however, in such diseases as diabetes, malaria and pernicious anaemia, and also in traumatic shock. Finally, athero-sclerosis of the kidney may occur, reducing the total blood flow through the kidney’s blood vessels.
What happens to the kidneys when incompatible blood has been used in a transfusion? Hemolysis of red cells occurs, of course, and the liber ated hemoglobin circulates in the blood. Passing through the kidney, hemoglobin (although its molecular weight is 68.000) passes through the membrane into the tubules. If the amount is small, reabsorption occurs, but in the amounts increased after an incompatible transfusion the hemoglobin, passing through the tubules, is precipitated. This bloc ks the tu bules; they cease to function and finally die. Patients having received the wrong type of blood can often be saved if the blood is thoroughly alkalin- ized; an alkal ine filtrate is formed and thus prevents precipitation.
A common disease of the kidney, known as Bright’s disease, in cludes a number of different conditions. Bright was a physician estab lishing a connection between degenerative changes in the kidney and the presence of albumin in the urine. The discovery of albumin in the urine usually indicates a faulty working of the kidneys. It means that albumin from the blood plasma is being allowed to pass through the renal tubules, and thus be excreted in the urine. At the same time the damaged tubules fail to eliminate fluid. This fluid collects in the tis sues and causes swelling, or edema, of various parts of the body. The fluid is more likely to collect in the legs and in the eyelids. Hence the pufly face and swollen legs of the sufferers from advanced Bright’s disease.
It must not be assumed, however, that the presence of a small amount of albumin in the urine is necessarily a sign of Bright’s disease. It is often transient and of no great significance.
