598 THE SUB-MAXILLARY GANGLION AND ITS CONNECTIONS. 



auriculo-temporal are carried by the roots 2 and 3 from the sympathetic and glosso- 

 pharyngeal, which the auriculo-temporal nerve (A), as it passes through the parotid 

 gland (P), gives off to the gland. These are the secretory fibres for the parotid ; 

 their functions are stated in 145. 



Section of the trigeminus is followed by inflammatory changes in the tympanic cavity 

 (rabbit) ; the degree of inflammation varies much (Bcrthold and Griinhagen). Section of the 

 sympathetic or glossopharyngeal has no effect. 



The sub-maxillary ganglion (fig. 429, L) lies close to the convex arch of 

 the tympanico-lingual nerve and the excretory duct of the sub-maxillary gland 

 (M). Its roots are (1) branches of the chorda tympani, ii, which undergo 

 fatty degeneration after section of facial nerve. This root supplies secretory 

 fibres to the sub-maxillary and sub-lingual glands, but it also supplies vaso-dilator 

 fibres for the blood-vessels of the same glands ( 145). In addition, fibres are 

 supplied to the smooth muscular fibres in Wharton's duct. All the fibres of the 

 chorda do not pass into the gland ; some pass along with the lingual nerve into 

 the tongue (see Chorda, under Facial Nerve). (2) The sympathetic root of the 

 ganglion arises from the plexus around the submental branch of the external 

 maxillary artery (</), i.e., ultimately from the superior cervical ganglion ; it passes 

 to the gland, and contains secretory fibres, whose stimulation is followed by the 

 secretion of thick concentrated saliva (trophic nerve of the gland). It also carries 

 the vaso-constrictor nerves to the gland (p. 212). (3) The sensory root springs 

 from the lingual. Some of the fibres, after passing through the ganglion, supply 

 the gland and its excretory ducts, while a few issue from the ganglion, and again 

 join the tympanico-lingual nerve to reach the tongue. 



Pathological. Trismus, or spasm of the muscles of mastication, supplied by the third division, 

 is usually bilateral ; it may be clonic in its nature (chattering of the teeth), or tonic, when it 

 constitutes the condition of lock-jaw or trismus. The spasms are usually individual symptoms 

 of more extensive convulsions ; more rarely when they occur alone, they are symptomatic of 

 dista.se of the cerebrum, medulla, pons, and cortex of the motor convolutions {Eulenburg). The 

 spasms may be caused reflexly, e.g., by stimulation of the sensory nerves of the head. 



Paralysis. Degeneration of the motor nuclei, or an affection of the intracranial root of the 

 nerve, causes paralysis of the muscles of mastication, which is very rarely bilateral. Paralysis 

 of the tensor tympani is said to cause difficulty of hearing {Romberg), or buzzing in the ears 

 {Benedict). We require further observations upon this point, as well as upon paralysis of the 

 tensor of the soft palate. 



Neuralgia may occur in all the branches of the fifth. It consists of severe attacks of pain 

 shooting into the expansions of the nerves. It is usually unilateral, and in fact is often 

 confined to one branch, or even to a few twigs of one branch. The point from which the pain 

 proceeds is frequently the bony canal through which the branch issues. The ear, dura mater, 

 and tongue are rarely attacked. The attack is not unfrequently accompanied by contractions 

 or twitchings of the corresponding group of the facial muscles. The twitchings are either reflex, 

 or are due to direct peripheral irritation of the fibres of the facial nerve, which are mixed with 

 the terminal branches of the trigeminus. The reflex twitchings may be extensively distributed, 

 involving even the muscles of the arm and trunk. 



Bedness or congestion of the affected part of the face is not an unfrequent symptom in 

 neuralgia, and it may be accompanied by increased.or diminished secretion from the nasal and 

 buccal mucous membranes. This is a reflex phenomenon, the sympathetic being affected. 

 Reflex stimulation of the vaso-motor nerves frequently gives rise to disturbance of the cerebral 

 activities, owing to changes in the distribution of the blood in the head. Ludwig and Dittmar 

 found that stimulation of sensory nerves caused a reflex contraction of the arterial blood-vessels, 

 and increase of the blood-pressure in the cerebral vessels. Sometimes there is melancholy or 

 hypochondriasis, and in one case of violent pain in the inferior maxillary nerve, the attack was 

 accompanied by hallucinations of vision. 



The trophic disturbances which sometimes accompany affections of the trigeminus are parti- 

 cularly interesting. They are : a brittle character of the hair, which frequently becomes grey, 

 or may fall out ; circumscribed areas of inflammation of the skin, and the appearance of a 

 vesicular eruption upon the face [often following the distribution of certain nerves], and con- 

 stituting herpes, which may also occur on the cornea, constituting the neuralgic herpes cornea 

 of Schmidt-Rimpler. Lastly, there is the progressive atrophy of the face which is usually con- 

 fined to one side, but may occur on both sides {Eulenburg). It is caused very probably by a 

 trophic affection of the trigeminus, although the vaso-motor nerves may also be affected reflexly. 



