472 THE INTERNAL STRUCTURE 



8. The Connection of the Visceral System of Nerves 

 with the Brain. 



The relation of the Systemic Nerves to the Brain is not 

 essentially different in Man from what obtains in the great 

 majority of higher Vertebrates. In all alike the Visceral 

 System of Nerves is divisible into two parts, whose 

 connections with the Brain are partly ' direct * and partly 



* indirect.' 



1. The Cerebral Systemic Nerves. The lowest seg- 

 ment of the Brain the Medulla is placed in immediate 

 relation with the greater number of the viscera of the 

 body through the intervention of the Glosso-pharyngeal 

 and the Vagus, as * ingoing ' nerves. They connect it 

 with the whole length of the alimentary canal below the 

 buccal cavity ; with the respiratory organs ; with the heart 

 and some of the great vessels ; with the liver, the spleen, 

 the kidneys, and possibly also with the internal organs of 

 generation. 



From the same region of the brain (the Medulla) certain 



* outgoing ' fibres are also given off to some of the above- 

 mentioned internal parts or viscera. These efferent or 

 motor fibres are not gathered together into separate 

 trunks ; they are principally wrapped up with, and con- 

 stitute parts of, the Glosso-pharyngeal and the Spinal 

 Accessory Nerves. The viscera which do not receive 

 ' outgoing ' fibres from this source are supplied with them 

 from the Spinal Cord and the nervous apparatus now to 

 be mentioned. 



2. The ' Great Sympathetic ' is an elaborate and 

 extensive system of nerves, and consists of the follow- 

 ing parts : (a.) A ganglionated cord lying on each side 

 of the vertebral column, each of which is connected above 

 with the 5th, the 6th, the 7th, the 8th, and the 9th 





