

NERVE-ENDINGS IN TENDONS. 



3-17 



with another and becoming fused together at the points of junction, or may end 

 either simply or with small knobbed extremities without uniting with other fibrils 

 into a nervous network ; or, according to the view of some histologists, may pass 

 into the cells of the tissue and thus terminate. 



-A " nervous network" is not to be confounded with a " nervous plexus." In the former 

 an actual fusion of the ultimate fibrilla? which result from the division of the axis-cylinders 

 of the nerves is assumed to take place, whereas in the latter, although there may appear to be 

 an intimate union between the different nerves which enter into the plexus, this union does 

 not extend to the ultimate elements of the nerve-fibre ; in other words, although fibres or parts 

 of fibres (fibrils) may be given and received by the several nerves to and from one another, 

 these fibres (in the case of the larger plexuses) or fibrils (in the microscopic plexuses) remain 

 completely distinct, although they may run in close juxtaposition. Nervous plexuses are of 

 very common occurrence, both those of the larger sort which have long been recognized by 

 anatomists, and the smaller microscopic plexuses which are very often found near the endings, 

 both of some centripetally conducting, and of some centrifugally conducting nerves. But 

 nervous networks are far less frequent than has been supposed, although they were until 

 lately described as a mode of nerve-termination not by any means rare, and indeed their exist- 

 ence is now doubted altogether by some histologists. (Compare Waldeyer, Ue. d. Endigungs- 

 weise der sensiblen Nerven : Archiv. f. mikr. Anat. XVII. s. 367.) 



Nerve-endings in tendons. Special modifications of the plexiform mode of 

 ending of sensory nerves have been described in various peripheral organs, but those 



Fig. 408. ORGAN OF (TOLGI FROM THE HUMAN TENDO ACHILLIS. CHLORIDE OF GOLD PREPARATION. 



(Ciaccio. ) 



in, muscular fibres ; t, tendon-bundles ; G, Golgi's organ with the axis-cylinder of the nerves, n, 

 ramifying between the small connective tissue bundles. 



only which are found in the tendons of muscles will here be noticed, the modes of 

 termination in other parts being deferred until the several organs are treated of. 



Most of the nerve-endings in tendon seem referable to one or other of the end- 

 organs which have already been described, although they present considerable 

 modification of form. In some tendons end-bulbs like those in the conjunctiva are 

 found (Sachs), and small Pacinian corpuscles of simple structure occur occasionally 

 in the areolar tissue sheaths of tendons and ligaments. But in many tendons, at 

 their junction with the muscles, there occur, as was first shown by Golgi, long 

 spindle-shaped bodies, composed apparently of a number of tendinous bundles more 

 or less fused into one, into which one or more medullated fibres pass, and after 

 dividing a certain number of times, their axis-cylinders spread themselves out 

 between the smaller tendon bundles, and collectively form a branched expansion 

 which is not unlike the terminal ramification in which the motor nerves to the 

 muscles themselves end (fig. 408). The peculiar spindle-shaped organ, which is thus 

 provided with a rich nervous network, is known as an organ of Golgi. Various 



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