102 NERVOUS SYSTEM. 



branches from the superior ganglion of the neck and a sensory 

 branch from the lingual branch of the fifth nerve. Its motor branch 

 is through the chorda tympani nerve from the seventh or facial 

 nerve. Its branches are distributed to the submaxillary gland and 

 control its function. 



Describe the otic ganglion. 



It is a small ganglion lying upon the third division of the fifth 

 nerve as it emerges from the foramen ovale. It has branches from 

 the sympathetic on the middle meningeal artery, and both a motor 

 and a sensory communication from the fifth, as well as a branch from 

 the glosso-pharyngeal through Jacobson's nerve. Its branches are 

 motor, to the tensor palati and tensor tympani muscles ; and sensory, 

 to the mucous membrane of the tympanum and Eustachian tube. 



How does the sympathetic system in the trunk communicate 



with the spinal nerves? 



From each spinal nerve is given off a communicating branch to 

 a neighboring ganglion. These branches contain both motor and 

 sensory fibres. 



How are the ganglia classified ? 



Into cervical, thoracic, abdominal, and pelvic ganglia and 

 plexuses. 



Describe the cervical ganglia. 



There are two a superior and inferior (with sometimes a third, 

 middle) ganglia on each side (Fig. 26). These ganglia receive 

 communications from each of the cervical spinal nerves and from 

 each other. Their branches are given off to form (1) the carotid 

 plexus, which follows the carotid artery and its branches. It forms 

 by its inosculations the vaso-motor plexuses of the arterial system, 

 and furnishes branches for distribution to the thyroid gland, larynx, 

 trachea, pharynx, and oesophagus. (2) It furnishes the cardiac 

 nerves, which are distributed in the cardiac plexus. 



What is the distribution of the thoracic ganglia? 



In the chest the ganglia are numerous (Fig. 26), and each gan- 

 glion receives two branches of communication from the intercostal 

 nerve above it, while the relationship of the ganglia is maintained 

 by the intercommunicating chain. The nerves originating here 

 are distributed to the plexuses on the thoracic aorta, and to those 

 of the lungs and oesophagus. 



