654 HANDBOOK OF PHYSIOLOGY. 



mentor nerves of the heart arise in the thoracic raml, pass upward 

 through the ganglion stellatum (first thoracic ganglion), the annulus of 

 Vieussens and the inferior cervical ganglion, and are distributed to the 

 heart; the vaso-motor roots of the brachial plexus, in the anterior roots 

 of the second and lower thoracic nerves, and reach that plexus by the 

 same ganglion ; the vaso-motor nerves of the foot leave the spinal cord 

 high up, and reach the sympathetic lateral ganglia above the origin of 

 the sciatic nerve, into which they pass through the abdominal sympa- 

 thetic. In all cases the nerves lose their medulla in the ganglia. 

 Similarly the vaso-motor nerve supply for the blood-vessels of the head 

 and neck and of the abdomen is derived from the cervical and abdominal 

 splanchnics respectively, or from the corresponding rami eiferentes of 

 the upper lumbar ganglia. 



The lateral sympathetic chain Gaskell proposes to call the chain of 

 vaso-motor ganglia. 



ii. Vaso-inhibitory or Vaso-dilator, and Cardio- inhibitory Fibres. 

 Of these, which are doubtless as widely distributed as the vaso-motor 

 fibres, we have distinct proof in the existence of fibres separate from 

 vaso-motor, e.g. , in the inhibitory nerve of the heart, the cardio-vagus; 

 in the chorda tympani ; in the small petrosal, and in the nervi erigentes. 



These nerve-fibres, as far as we know at present, leave the central 

 nervous system among the fine medullated nerves of the cervico-cranial 

 and sacral rami communicantes, do not enter the lateral ganglia, but 

 pass without losing their medulla into the collateral or terminal 

 ganglia. 



(b.) i. Viscero-nwtor Fibres. These fibres, upon which depend the 

 peristaltic movements of the thoracic portion of the oasophagus, and of 

 the stomach and intestines, arise from the central nervous system, as 

 the fine medullated fibres of the upper portion of the cervical region, not 

 in the spinal nerve-roots of that region, but as the bundles of fibres 

 which may be called the rami viscerales of the vagus and accessory nerves. 

 They pass to the ganglion of the trunk of the vagus, where they lose 

 their medulla. 



ii. Viscero- Inhibitory Fibres. It appears that the nerve supply to 

 the circular muscles of the alimentary canal and its appendages, is con- 

 tained in the abdominal splanchnics, and consists of those fibres which 

 have not passed through the lateral chain, and which therefore retain 

 their medulla until they reach the proximal or collateral chain. 



(c.) Glandular Nerve- Fibres. A double nerve supply, in all proba- 

 bility coinciding with the supply to the visceral muscles, has been 

 demonstrated in the cases of the submaxillary, parotid, and lachrymal 

 glands, and in these cases the course of the fibres is very similar to 

 that of the corresponding fibres for the vaso-muscular supply. Thus 



