526 MANUAL OF PHYSIOLOGY. 



belong chiefly, if not altogether, to the chorda tyrnpani, and leave 

 this lingual branch of the fifth to join the seventh nerve on their 

 way to the trunk of the glosso-pharyngeal. 



There are four ganglia in close relation to the branches of the 

 fifth nerve which have certain points of similarity, and may, 

 therefore, be considered together, although their different posi- 

 tions show that they are engaged in the performance of very dif- 

 ferent functions. 



We have not yet been able to ascertain the value of these little 

 points of junction of motor, sensory, vaso-motor, and secretory 

 fibres, because, so far, we are unable to attribute to the cells of the 

 ganglia either reflecting or controlling action, or any automatic 

 power. 



They have all efferent (motor and secretory) and afferent (sen- 

 sory) connections with the nervous centres, and also connections 

 with the main channels of the sympathetic nerves. These are 

 spoken of as the roots of the ganglia. Their little branches are 

 generally mixed nerves. 



THE CILIARY OR OPHTHALMIC GANGLION. 



This ganglion lies in the orbit. It has three roots, which come 

 from (1) the inferior oblique branch of the third nerve, by a 

 short slip, which forms the motor root ; (2) from the nasal branch 

 of the ophthalmic division of the fifth, and from the carotid plexus 

 of the sympathetic. The branches go mostly to the ball of the 

 eye, and may be divided into those which are afferent and efferent. 

 The afferent are only sensory branches, connecting the cornea 

 and its neighboring conjunctiva with the centres. The efferent, 

 or motor fibres, are those that go to the dilator pupillse (coming 

 mostly from the sympathetic), and the vaso-motor fibres going to 

 the choroid coat, iris, and the retina. 



THE SPHENOPALATINE OR NASAL GANGLION. 



This lies on the second division of the fifth nerve, from which 

 it gets its sensory root. Its motor root comes from the seventh 

 by the great superficial petrosal nerve, and its sympathetic root 



