. The elements of pathological histology with special reference to practical methods . e :—(a) Atheror)iaor arteriosclerosis {chronic endarteritis).—This process either involves thewhole of the arterial system, or is restricted to isolated areas only ATHEROMA 205 (aorta, arteries of brain, kidneys and heart), but in both cases chieflyaffects the points where the branches come off. Its cause probablylies in a diminution of the elasticity of the vessel-wall brought aboutby general disturbances of nutrition (advanced age, alcoholism, etc.),which is afterwards followed by increased expansion of th
. The elements of pathological histology with special reference to practical methods . e :—(a) Atheror)iaor arteriosclerosis {chronic endarteritis).—This process either involves thewhole of the arterial system, or is restricted to isolated areas only ATHEROMA 205 (aorta, arteries of brain, kidneys and heart), but in both cases chieflyaffects the points where the branches come off. Its cause probablylies in a diminution of the elasticity of the vessel-wall brought aboutby general disturbances of nutrition (advanced age, alcoholism, etc.),which is afterwards followed by increased expansion of the wall bythe blood-pressure, leading to widening of the lumen and slowing ofthe blood-current, and lastly by a new formation of connective tissuein the intima. The latter change, which is preceded also by anincreased development of the vasa vasorum, begins microscopicallywith the appearance in the intima of collections of small cells, whichgradually change to connective tissue and lead to thickenings of thiscoat, usually circumscribed (Fig. 105, a). In this way an adaptation of. Fig. 105.—Atheroma of Aorta, x 80. (Alum cochineal.) o, Thickened intima; of lime in middle coat; c, Cellular infiltration of middle coat. the calibre of the arteries to the altered current would again beattained if degeneration, partly hyaline and partly fatty, did notsubsequently set in. Owing to the former the connective tissue of thethickened intima becomes homogeneous, losing its striation and itscells, while the latter causes the appearance of minute droplets of fatin the protoplasm of the connective-tissue cells, and also external tothem. The thickened intima may also at times assume the characterof mucous tissue. In consequence of insufficient nutrition, the new tissue often breaksdown subsequently into a finely-granular detritus mixed with fat-drop- 206 THE BLOOD-VESSELS lets and crystals of cholestearin (atheromatous pulp); and this process,advancing towards the internal surfac
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpatholo, bookyear1895
