158 



MYOLOGY. 



The fibres never terminate in tendons, and are not invested in 

 a sarcolemma ; they are cylindrical in shape, and composed of 

 fusiform or elongated cells, which become apparent after macera- 

 tion of the tissue in dilute hydrochloric acid or other reagents, or 

 it may be without any such preparation. These cells are the 

 contractile cells of Kolliker, and in them an elongated nucleus 

 may be visible. The fasciculi vary very greatly in size in 

 dift'erent situations, and often crossing each other, they give the 

 tissue in some parts a mesh-like appearance. The non-striped 

 tissue is very abundant, being found in the walls of the alimen- 

 tary canal and hollow viscera, in gland ducts, in the coats of 

 ^ T, c blood-vessels, in the skin, and elsewhere. 



Both varieties of muscular tissue are 

 plentifully supplied with blood, and in stri- 

 ated tissue the capillaries or minute blood- 

 vessels are arranged longitudinall}'' with 

 transverse connecting branches, but they 

 do not penetrate the sarcolemma, they and 

 the larger vessels alike being found in the 

 perimysium or interstitial connective tissue. 

 The striated tissue is supplied with nerves 

 from the cerebro-spinal system, but the non- 

 striated tissue receives its supply from the 

 sympathetic system, and the vital stimulus 

 conveyed by either of these causes the con- 

 traction of the fibres. 



The description of the arrangement of involuntary^ tissue forms 

 no part of the present section of our subject; the tissue is 

 described here chiefly in order that its structure may be com- 

 pared with that of the voluntary kind 



Fig. 69. 



A, Non-striated muscular 

 fibres ; a a, The component 

 fusiform cells ; b i, The 

 nuclei. B and C, Single cells 

 more highly magnified ; C 

 having been treated with 

 acetic acid. 



TENDONS. 



The tendons in which voluntary muscles terminate at either 

 end are structures resembling ligaments in their composition, 

 being formed of white fibrous tissue mixed with yellow fibres. 

 Like ligaments, they are practically non- elastic, and while they 

 attach the muscles to the bones, they merely transmit the action 

 of the former to the latter, and are therefore jDassive instruments 

 of motion. 



The extremity of a muscle which has the most fixed attachment 



