140 



TUBERCULOSIS 



generalized 



In secondary or 

 tuber- 

 culosis one or more 

 of the organs, 

 omentum, serous 

 membranes, or lym- 

 phatic system may 

 become more or less 

 thickly sprinkled 

 with minute grey- 

 ish nodules about 

 the size of a millet 

 seed. These tuber- 

 cles are at first al- 

 most the color of 

 mother-of-pearl but 

 later as the central 

 caseous degenera- 

 tion begins they be- 

 c o m e grayish. 



Giant cells are usu- 

 ally numerous. 



In studying the 

 lesions in a fatal 

 case of tuberculosis 



Fig. 27. Dorsal aspect of bovine lutigs show, 

 ing position of the posterior mediastinal glands, 

 a, d, c, c'., caudal, ventral, cephalic lobes, f 

 oesophagus, g. muscular pillars of diaphragm- 

 h. posterior aorta. ^. left bronchial gland, 

 i. caudal margin of the ligatnefit of the lung 

 Mediastinal glands are shown, most of them 

 resting on the oesophagus. The large caudal 

 one may find with gland restiyig on the pillars of the diaphragm is 

 varjuno" mod ifica- most frequently diseased and often attains an 

 tions one or more of enormous size. The remaining mediastinal 

 ,, P ,, . ,. glands are arranged in two sets on the right and 



thetollowmgcondi- , ., ■ ^,, ^, ,c n X 



° left margins oj the oesophagus. {^mUh.) 



tions, viz. 



( 1 ) The primary lesion may be found in any one of the 

 organs or membranes. Its comparative age is determined by 

 the character of the anatomical changes. It may be entirelj- 

 encysted, caseous or calcareous and dead. In addition to this 

 primar}^ focus, there may be a succession of tubercles of various 

 ages distributed in one or more organs. 



(2) The lesions may be restricted to one organ, as the 

 liver in which the primary focus has spread by continuity due 



