86 



MUSCULAR TISSUE 



fCH. VI. 



areolar tissue between the tendon-bundles becomes also continuous 

 with that between the muscular fibres (fig. 111). 



Blood-vessels of Muscle. The arteries break up into capillaries, 

 which run longitudinally in the endomysium, transverse branches 

 connecting them (fig. 112). No blood-vessels ever penetrate the 

 sarcolemma. The muscular fibres are thus, like other tissues, 

 nourished by the exudation from the blood called lymph. The lymph 

 is removed by lymphatic vessels found in the 

 perimysium. 



The nerves of voluntary muscle pierce the 

 sarcolemma, and terminate in expansions 

 called end-plates, to be described on p. 95. 

 Neuro-muscular Spindles. Bundles of fine 



the same 

 of muscular 6 ' 



FIG. 112. Three muscular fibres 

 running longitudinally, and 

 two bundles of fibres in trans- 

 verse section, M, from the 

 tongue. The capillaries, C, 

 are injected, x 150. (Klein 

 and Noble Smith.) 



muscular fibres enclosed within a thick lamel- 

 lated sheath of connective tissue are found 

 scattered through voluntary muscles ; they 

 are especially numerous near the tendons and 

 * n tn6 proximity of intra-muscular septa. It 

 is remarkable that they have not been found 

 in the ocular or tongue muscles. These structures are called neuro- 

 muscular spindles; they vary in length from to J- inch, and are 

 about T i T inch in diameter. Each receives a nerve fibre which 

 divides into secondary and tertiary branches. The myelin sheath 

 is lost, and the tertiary branches encircle the muscular fibres, 

 breaking up usually into a network. It is believed that these 

 are sensory end organs in the muscle. (See further, chapter on 

 Touch.) 



, 

 (Ranv 9 ic ti r x ) edtosarc lemma ' 



