PERIPHERAL NERVES AND THE SYMPATHETIC SYSTEM 253 



(1) To the circulation apparatus: 



(a) The inhibitory fibres. 



(b} Sensory and reflex-acting (depressor) to the 

 heart. 



(2) To the respiratory apparatus: 



(a) Motor fibres for the muscles of the larynx (in 

 the superior laryngeal for the crycothyroid, in the 

 recurrent laryngeal for the other muscles) and for the 

 bronchial muscles. 



(b) Sensory fibres for the larynx (laryngeal superior), 

 trachea, and lungs. 



(3) To the muscles of the alimentary canal : 



(a) Motor fibres for the movement and peristalsis of 

 the esophagus, stomach, and intestine. 



(b) Sensory fibres for the esophagus and stomach. 

 (<:) Secretory fibres for the stomach and probably 



also for the pancreas and glands of intestine. 



In addition to these the vagus is supposed to contain fibres 

 which regulate the sugar formation in the liver. 



XII. The hypoglossus is the motor nerve for the muscles 

 of the tongue. 



3. SYMPATHETIC SYSTEM 



The sympathetic nerves are connected with the central 

 nervous system by the rami communicantes, which pass from 

 the trunks of the spinal nerves to the sympathetic ganglia. 

 The sympathetic contains the vaso-motor fibres for the entire 

 body. These pass either directly to the vessels or first join 

 the peripheral nerves and, in common with them, continue 

 their course. The sympathetic also sends secretory nerves 

 to the sweat glands. 



Besides these the sympathetic contains : 



(i) In the cervical region 



(a) Fibres for the dilation of the pupil. 



(b) Secretory fibres for the salivary and lachrymal 

 glands. 



(c) Cardio-augmentor fibres. 



