NERVE 199 



their cell stations in the inferior mesenteric srancrlia, from 

 which they run in the hypogastric nerves to the pelvic 

 plexus. Ttiey are vaso-constrictor, inhibitory to the colon, 

 and generally motor to the bladder, uterus, and vagina. 



(5) Arm. — These fibres, coming out by the middle dorsal 

 nerves, have their synapses in the ganglia of the sympathetic 

 chain, and passing back into the spinal nerves by the grey 

 rami, course to the blood-vessels, hairs, and sweat glands 

 of the limb. 



(6) Leg. — The fibres take origin from the lower dorsal 

 and upper 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. 



II. The Cranial and Sacral, or Para - sympathetic Fibres — 

 These pass out from the upper and lower ends of the cord. 

 They do not pass through the lateral ganglia but have their 

 cell stations in some of the collateral orandia. 



(a) Cranial — 



(1) The third cranial nerve carries fibres which have 

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

 sphincter pupillae 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 gfansflion. 



(4) The vagus sends inhibitory fibres to the heart, which 

 form synapses in the cardiac plexus. It also sends augmentor 

 fibres to the a3sophagus, stomach and intestine. 



(6) Sacral — 



The nervi erigentes or pelvic nerves 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 ; they inhibit the sphincter of the bladder, and are 

 motor to the bladder, colon, and rectum. 



