ioi8 



HUMAN ANATOMY. 



Fig. 873. 



Cylindrical end-bulb from con- 

 nective tissue layer of skin. X 180. 

 (Szymonowicz.) 



A 



a number of bold curves and twistings. After the disappearance of their sheaths, 

 the naked axis-cyhnders undergo repeated divisions, the resulting fibrillae becoming 



varicose and intertwined and ending in free terminal 

 knob-like enlargements. 



In contrast to the foregoing end-organs, in which 

 the axis-cylinder subdivides into numerous terminal 

 threads disposed as more or less elaborate intertwinings, 

 a second group is distinguished by the possession of a 

 thick laminated capsiile that encloses a cylindrical core or 

 inner bulb containing the slightly branched axis-cylinder. 

 These endings, of which the Pacinian corpuscle is repre- 

 sentative, are relatively large and ellipsoidal. 



A transitional form, connecting them with the 

 spherical end-bulbs, is presented by the cylindrical 

 end-bulbs of Krause. These are found in various 

 parts of the corium, the oral mucous membrane and 

 between the bundles of striped muscle and of tendon. 

 They are irregularly cylindrical in form, often more or 

 less bent, and consist of a thin laminated capsule that encloses a core of semifluid 

 substance in which lies the centrally placed axis-cylinder. The latter, after losing 

 the medullary sheath on entering at the proximal end of the capsule, traverses the 

 core without branching until near the distal pole, where it ends in a single or slightly 

 subdivided terminal enlargement. 



The Vater-Pacinian Corpuscles. — These structures, the most highly special- 

 ized sensory end-organs, are relatively large ellipsoidal bodies, from .5-1.5 mm. in 

 length and about one-third as much in breadth, situated within the connective tissue 

 in many parts of the body. 



In man they are found in Fig. S74. 



the deeper layers of the 

 connective tissue layer of 

 the skin, especially on the 

 palmar and plantar aspects 

 of the fingers and toes, in 

 the connective tissue in the 

 vicinity of the joints, in 

 tendons, in the sheath of 

 muscles, in the periosteum 

 and in the tunica propria 

 of the serous membranes, 

 the peritoneum, pleura and 

 pericardium. They are 

 particularly large in the 

 mesentery of the cat, where 

 they may be readily de- 

 tected with the unaided eye 

 as oval pearly bodies some- 

 times two millimeters or 

 more in length. 



The most conspicuous 

 part of the Pacinian body 

 is the robust capsule that 

 constitutes almost the en- 

 tire bulk of the corpuscle 

 and consists of from one 

 to three dozen thin con- 

 centric lamellae of fibrous 

 tissue. The surfaces of the . 



iamelte are covered with endothelial plates whose nuclei appear as fusiform thicken- 

 ings, along the concentric stria; of the corpuscle. The axis of the Pacinian body 



->?. 





/r 





Vater-Pacinian corpuscles from skin of child's finger; A, longitudinal; 

 B, transverse section ; w, nerve entering capsule to reach inner bulb. X 105. 



