146 HUMAN PHYSIOLOGY 



spinal nerves by the grey rami, course to the blood vessels, 

 veins, and sweat glands of the limb. 



6. Leg. The fibres take origin from the eleventh dorsal 

 to the third lumbar nerves, have their cell stations in the 

 lateral ganglia, and pass to the leg in the same way as do the 

 fibres to the arm. 



Outgoing Visceral Fibres not connected with Sympathetic 

 Ganglia. Certain outgoing fibres to the viscera and involun- 

 tary structures pass directly without going through the 

 sympathetic ganglia. 



1. The third cranial nerve carries fibres which have their 

 synapses in the ciliary ganglion, and pass on to the sphincter 

 pupilke and ciliary muscle. 



2. The seventh nerve carries fibres through the chorda 

 tympani to cell stations in the submaxillary and sublingual 

 ganglia. These are secretory to the submaxillary and sub- 

 lingual glands. 



3. The ninth nerve sends fibres to the parotid gland, which 

 have their cell station in the otic ganglion. 



4. The vagus sends inhibitory fibres to the heart, which 

 form synapses in the cardiac plexus. It also sends motor 

 fibres to the oesophagus and stomach, which, in some animals 

 at least, have the cell stations in the ganglion of the 

 trunk. 



5. The nervi erigentes come off from the second and third 

 sacral nerves, and pass to the hypogastric plexus near the 

 bladder where the fibres have their cell stations. They are 

 the vaso-dilator nerves to the pelvic organs, inhibit the 

 retractor penis, and are motor to the bladder, colon, and 

 rectum. 



(6) Ingoing Fibres. The course of these from the viscera 

 is not so clearly known ; but they appear to enter the main 

 nerve largely by the white rami. In the normal condition 

 stimulation of their peripheral endings does not lead to 

 modifications of consciousness, and is therefore not accom- 

 panied by pain (see p. 96). But in abnormal conditions 

 painful sensations are produced. In some cases, abnormal 

 stimulation of visceral nerves leads to painful sensations 

 referred to the cutaneous distribution of the spinal nerve 

 with which they are connected. Thus disease of the heart 



