ABDOMEN. 261 



THE SYMPATHETIC NERVE. 



In the cranium, neck, thorax, abdomen, and pelvis you will have to do with 

 arteries, nerves, viscera, and localities where the sympathetic nerve, while perhaps 

 anatomically the smallest structure, in these localities is nevertheless the most 

 important structure. It would be just as wanton to ignore and destroy, or, 

 what is worse, fail to see, the hairspring of a watch, if you were taking a watch 

 to pieces, as it would be to dissect a human body and not have a clear under- 

 standing of the sympathetic nerve. 



The necessity of at least familiarity with the rudiments of this system of 

 nerves will be apparent, when I remind you that you will hear more or less 

 about the sympathetic nerve from every chair in your medical course. The 

 physiological action of drugs depends on vaso-contraction and dilatation to a 

 great extent. The rationale of the obstetrician's Crede manipulation, is stimula- 

 tion of sympathetic uterine contraction. The physiologist invokes the sympa- 

 thetic system when he would explain the function of viscera. The pallors and 

 hyperaemias, the exanthemata, and the thousand and one strange phenomena in 

 skin diseases are, to a greater or less degree, temporarily or permanently amen- 

 able to remedies that act in some way through the sympathetic. In general 

 and special medicine, in surgery and all its special departments, you will hear of 

 parts played by the sympathetic nerve. Are you, then, to remain in ignorance, or 

 are you to gain a comprehensive knowledge of this subject by intelligent dissection ? 



An erroneous opinion prevails among students that the sympathetic cannot 

 be seen, on account of its smallness. No ; this is not the reason students often fail 

 to find and become familiar with these nerves. You can see at a distance of six 

 feet the cervical, thoracic, and abdominal ganglia, of the gangliated cord. You 

 can see at a distance of ten feet the solar and cardiac plexuses. You can see at a 

 distance of four feet the hypogastric plexus. You can see at a distance of two 

 feet the communicating branches extending from one ganglion to another of the 

 gangliated cord. You can see the greater and lesser splanchnics five feet away. 

 At a distance of fourteen inches you can see the rami communicantes the little 

 nerves connecting the sympathetic cord and the anterior primary divisions of the 

 spinal nerves. At a distance of twelve inches you can see the gastric, hepatic, 

 splenic, and mesenteric sympathetic nerves. At a distance of ten inches you can 

 see the sympathetic nerves on the internal carotid artery in its cavernous, petrosal, 

 or cerebral stages. You can see the Vidian nerve, the petrosal nerves, the ophthal- 

 mic ganglion. At the closest normal visual range you can even see the sympa- 

 thetic nerves that accompany the ovarian and uterine arteries. You can even 

 see the long and short ciliary nerves to the eyeball. 



I saw a man last summer who could not see the moon through a Yerkes 

 telescope. In this case the moon was on exhibition, and the powerful lens was 

 in working order, but the man in question did not know where to look. So, in 

 anatomy, the sympathetic nerve is everywhere on exhibition. Its dimensions 

 are not great, it is true ; still, if you know where to look, you will have no diffi- 

 culty in finding this nerve. The peculiar sympathetic lustre makes its identity 

 certain, after you have dissected and studied this nerve a short time. The object 

 of this chapter is to teach you where to look, to find the sympathetic nerve in 

 all regions of the body ; to teach you how to let the nerve alone, having once 

 found the same and this is its dissection ; to furnish you with an outline, 

 embracing the rudiments of what is known of the sympathetic to-day and this 

 by the following questions and their answers : 



I . What is a sympatJietic nerve ? 



Cranial and spinal nerves are collectively designated somatic nerves. These 



