STRUCTURAL CHANGES DUE TO DAMAGE. 



339 



the development of fibrous tissue, which may become modified into 

 adipose tissue, or by bone-production if the damage causes a re- 

 juvenescence of periosteum or endosteum. 



6. Smooth Muscular Tissue. Non-striated muscle-cells are capa- 

 ble of multiplication, but in inflammatory conditions the tissue of 

 the media of the vessels does not appear to keep pace with that of 

 the intima in the production of new bloodvessels. The latter, 

 therefore, usually lack a muscular coat and are thin- walled (Fig. 

 272). In the uterus and other situations smooth muscle-cells may 

 multiply and occasion a hyperplasia of the tissue. This appears, 

 however, to be in response to a functional demand, rather than one 



Fro. 305. FIG. 306. 



r . 



FI'LT. :'.().">. Karyokinetic figures in smooth muscular fibres. (Busachi.) 



Fig. 306. Regeneration of a striated muscle-fibre. (Kirby.) a, remains of the old contractile 

 substance ; 6, rejuvenating cytoplasmic fragments, with their nuclei ; c, similar fragment 

 containing a bit of old contractile substance and a nucleus in karyokinesis, d. 



of the results of damage : a functional hyperplasia. Karyokinetic 

 figures have been observed in smooth muscle-cells after damage, 

 but they do not lead to a restoration of the original tissue, which 

 heals with the formation of a scar (Fig. 305). 



7. Striated Muscle. When a striated muscle-fibre undergoes 



