Sclerosis

SCLEROSIS (from Greek scleros-hard), sclerosis, the proliferation of connective tissue in various organs. S. can be diffuse and focal. In diffuse S., significant hardening of the entire organ is noted, the surface of which often becomes uneven, finely or coarsely granular, sometimes nodular; hence the terms granular kidney (see Nephrosclerosis), nodular liver, etc. "Granularity or nodularity is connected, on one hand, with the uneven development of S itself; on the other hand, with phenomena of compensatory hypertrophy and hyperplasia of the remnants of the parenchyma of the sclerosing organ. Often S. is accompanied only by a decrease, hardening of the organ, its surface remains normal, smooth. The causes of S. can be various processes, pathological and physiological. Among pathological S., inflammatory ones occupy the most prominent place, especially those associated with chronic inflammations (syphilitic, rheumatic sclerosis; S. in tbc, actinomycosis, chronic suppurations, etc.). In essence, inflammatory S. do not differ from the processes of tissue scarring. S. can be associated with atrophic processes in the organ's parenchyma, with chronic circulatory disorders, e.g., with venous congestion (see Induration). S. often accompanies the development of the tumor process, e.g., in cancers of the scirrhous type. Physiologically, S. are associated with involution-age factors and are observed mainly in old age (arteries, uterus, ovaries, etc.), in the postpartum period (in the vessels of the uterus), in the places of development of the yellow bodies of the ovaries, etc. In the nervous system, sclerosis occurs mainly, and sometimes exclusively, due to the proliferation of glial elements (so-called glioses). In diffuse S., organs to a greater or lesser degree lose their physiological properties. In uneven, focal S., organ disfigurement often arises (saddle nose, lobulated liver in syphilitic S., pathological constrictions, narrowing of lumens, etc.).