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HANDBOOK OF PHYSIOLOGY. 



The Pacinian bodies or corpuscles (figs. 108 and 109), named after 

 their discoverer Pacini, also called corpuscles of Vator, are little elon- 

 gated oval bodies, situated on some of the cerebro-spinal and sympathetic 

 nerves, especially the cutaneous nerves of the hands and feet; and on 

 branches of the large sympathetic plexus about the abdominal aorta. 

 They often occur also on the nerves of the mesentery, and are especially 

 well" seen even by the naked eye in the mesentery of the cat. They have 

 been observed also in the pancreas, lym- 

 phatic glands, and thyroid glands, as 

 well as in the penis of the cat. Each 

 corpuscle is attached by a narrow pedicle 

 to the nerve on which it is situated, 

 and is formed of several concentric 

 layers of fine membrane, consisting of a 



Fig. 108. Fig. 109. 



Fig. 108. Extremities of a nerve of the finger with Pacinian corpuscles attached, about the 

 natural size (adapted from Henle and Kolliker) . 



Fig. 109. Pacinian corpuscle of the cat's mesentery. The stalk consists of a nerve-fibre (N) 

 with its thick outer sheath. The peripheral capsules of the Pacinian corpuscle are continuous with 

 the outer sheath of the stalk. The intermediary part becomes much narrower near the entrance of 

 the axis-cylinder into the clear central mass. A hook-shaped termination with the end-bulb (T) is 

 seen in the upper part. A blood-vessel (V) enters the Pacinian corpuscle, and approaches the end- 

 bulb ; it possesses a sheath which is the continuation of the peripheral capsules of the Pacinian 

 corpuscle. X 100. (Klein and Noble Smith.) 



hyaline ground membrane with connective-tissue fibres, each layer being 

 lined by endothelium (fig. 109); through its pedicle passes a single nerve- 

 fibre, which, after traversing the several concentric layers and their 

 immediate spaces, enters a central cavity and, gradually losing its dark 

 border and becoming smaller, terminates at or near the distal end of the 

 cavity, in a knob-like enlargement or in a bifurcation. The enlarge- 



