THE TISSUES. 



then divide before reaching the nerve end-organs, and divide several 

 times as they pass through the capsule, periaxial space, and axial 

 sheath. Within the axial sheath, the medullary sheath is lost, and 



the naked axis-cylinders terminate in 

 one or several ribbon - like branches 

 which are wound circularly or spirally 

 about the intrafusal fibers (annulospiral 

 ending) or they may terminate in a 

 number of larger branches which again 

 divide, these ending in irregular, round, 

 oval, or pear-shaped discs {flower-like 

 endings), which are also on the intra- 

 fusal fibers. These flower-like endings 

 are usually at the ends of the annulo- 

 spiral fibers. In the smaller end- 

 organs only one area of nerve-termi- 

 nation has been observed ; in the 

 larger, two, three, or even four such 

 areas may be found. 



Neuromuscular nerve end-organs 

 are found in nearly all skeletal muscles 

 (not in the extrinsic eye muscles nor 

 in the intrinsic muscles of the tongue), 

 but they are especially numerous in 

 the small muscles of the hand and foot. 

 They are found in amphibia, reptilia, 

 birds, and mammalia, presenting the 

 same general structure, although the 

 ultimate termination of the nerve-fibers 

 varies somewhat in the different classes 

 of vertebrates. 



Neurotendinous Nerve End -organ 

 (Golgi Tendon Spindle). In 1880 

 Golgi drew attention to a new nerve 

 end-organ found in tendon, describing 

 quite fully its general structure and 

 less fully the nerve termination found 

 therein. These nerve end-organs are 

 spindle - shaped structures, which in 

 man vary in length from 1.28 mm. to 

 1.42 mm., and in breadth from 0.17 

 mm. to 0.25 mm. (Kolliker). Ciaccio 

 mentions a neurotendinous nerve end- 

 organ found in a woman, which was 2 

 or 3 mm. long. A capsule consisting of 



from 2 to 6 fibrous tissue lamellae, and 



broadest at the equatorial part of the 

 Jour. Comp. Neural.," vol. x). end-organ, surrounds a number of in- 



Fig. 146. - Neurotendinous 



nerve end-organ from rabbit; teased 



