degeneration (de-jen-er-a's hun). i

Lo of race characteristics. 2. A retrogre ive change in molecular structure of the cells of a ti ue or organ, producing an impairment of function, adipose d. See fatty d. albuminoid d. A d. in which bodies are formed which are compounds of protein with other substances, as in mucoid degeneration, combining a protein and a carbohydrate. albuminous d. Syn.: cloudy szvelling. A d. characterized by a deposit of fine proteid granules in the cells of the heart muscle, the kidney, and the liver, following chemical poisons and the infectious diseases, amyloid d. A d. characterized by the infiltration of the media of arteries and the ti ue of the liver, kidney, spleen, and other viscera by a glycoprotein consisting of hist on combined with chondroitin-sulphuric acid. ascending d. The d. upwards after destructive lesions of centripetal nerve fibers, calcareous d. The impregnation of the ti ues and the gland secretions with calcium or magnesium salts, especially carbonates and phosphates. caseous d. See caseation, cheesy d. See caseation, cholesterin d. Waxy d., so called on account of the abundance of cholesterin in the waxy material, chondroid d. The proper term for amyloid d. colloid d. The deposit of an increased amount of a colloid composed of protein, consisting of globulin and iodothyrin in tumors of the thyroid gland and pituitary body, cystic d. The formation of a number of di eminated cysts in an organ or its enlargement in the form of a cyst, as in the kidney, descending d. In neuropathology, the destruction and disintegration of nerve fibers from above downward, i. e., from the central or cerebral extremity of such fibers toward their peripheral extremity. This proce . is caused by the presence of some lesion (called primary) which interrupts the continuity of the degenerating fibers and marks the upper limit of the degeneration. earthy d. See calcareous d. and calci- Hcation. elastoid d. A d. of the internal lamina of the arteries during involution of the uterus after delivery, fascicular d. An atrophic proce , in paralyzed muscles due to injury 01 disease of the motor ganglion cells of the central tube of gray matter of the spinal cord or of the efferent fibers which connect them with the muscles, fatty d. The deposit of minute fat granules in the cytoplasm of the cells of the liver, kidney, heart muscle, and endothelial cells: of blood ve els, accompanied by degenerative changes in the nucleus, and caused by chemical poisons, malnutrition, and bacterial infections. gelatin i form d. See colloid d. granular d. A d. which is usually the result of autolysis of infarctions, thrombi, etc., and the degeneration of the epithelium of the tubules of the kidney, producing leucin, tyros in, peptones and albuminoids, gray d. D. resulting from chronic inflammation in nervous ti ue, its peculiarity being the gray color which is apparent, hem a to hyaloid d. A d. forming hyaline thrombi in blood ve els from conglutinated red corpuscles, blood platelets, or fibrin fibers. hyaline d. The deposit of a hyaline material of a glycoproteid nature in the interstitial ti ue of arteries, the kidney, ovary, and myocardium, and also in granulomata and the parenchymatous cells of various organs and malignant tumors. The material differs from amyloid in showing no specific reaction with iodin. hydropic d. The formation of vacuoles containing a serous fluid in the cytoplasm of cells, as in the lower layers of the epithelium of the skin in smallpox. keratoid d. A pathological change of epithelial cells into keratin, lardaceous d. See amyloid d. lipoid d. A d. characterized by the deposit of doubly refractive globules of cholesterin oleate in atheroma, cancer cells, and nerve ti ue, mucoid d. A variety of d. occurring usually in the connective ti ue of senile atrophic organs, myxedema, sarcomata, fibromata, carcinomata, myxomata, and ovarian cysts, myelinic d. The breaking down of ti ue cells into myelin; a proce sometimes occurring coincidently with fatty d. of the kidney and liver, and, in the normal proce , in the adrenal and mammary gland. The material is probably a lipoid body, allied to a soap and containing oleic acid, myxomatous d. See mucoid d. Ni l d. A d. of a nerve cell with lo of the Ni l bodies. o ific d. See o ification. parenchymatous d. See albuminoid d. pigmentary d. Pertaining to or containing pigment. senile d. The various degenerative changes of old age. uratic d. The invasion of the ti ues by deposits of uric acid and urates. Virchow's d. See amyloid d. vitreous d. See Zenker's d. waller i an d. The d. of a nerve fiber severed from its nutritive center, waxy d. See amyloid d. Zenker's d. A waxy d. affecting voluntary muscle and heart muscle. [Lat., degenerare, to degenerate.]