MlDOMKN. 265 



by accompanying the artery to the part. Hence it occurs that the ovary ami 

 testicle receive their nerve-supply from the renal plexus. 



In the subjoined figure the tendency of plexuses to supply areas below their 

 own level will be seen. 



19. What is meant by automatic action in sympathetic ganglia .' 



The ganglia of the heart and intestine have the power o'f independent action ; 

 still, the sympathetic is no longer considered a separate system. 



20. Is there any definite means of judging of the location of disease founded on 

 tlie iintiirc or location of pain .' (>/-, coin'crscly, may pain incident to disease of tlie 

 I'anous organs in the three great cai'itics t/iora.\, abdomen, and pelvis be ration- 

 al/}' accounted for in the distribution of ccrebro-spinal or somatic nerrcs .' 



Yes ; for, as the following pages will show, somatic nerves often report pain 

 that has its origin in an organ far away from the origin. These somatic nerves 

 also transmit both pain and motion more rapidly. 



I '"or an example, in valvular lesion the pain in the chest behind the sternum, 

 so long as reported by the sympathetic nerve to the patient as a subjective 

 symptom of disease, is constant and aching. When, however, the case assumes 

 a grave aspect, and the pain is reported to the patient's sensibility by the somatic 

 nerves, then an aching pain is replaced by one described as darting and stabbing. 

 Then, too, the location of the pain will have changed. The aching sympathetic 

 pain behind the sternum is now felt in the little and ring fingers. Consult the 

 characters of sympathetic and somatic pain in the following paragraphs. Con- 

 sult figure 185 and see : (i) The heart is supplied by sympathetic nerves by the 

 cardiac plexus ; (2) the sympathetic nerves forming the cardiac plexus com- 

 municate with the somatic nerves in the area where are given off the nerves 

 forming the brachial plexus ; (3) as sensory nerves report pain peripherally, 

 we may logically account for the digital pain in valvular lesions in the distri- 

 bution of the brachial plexus in general, or in the specific distribution of the 

 ulnar nerve in particular. . The same is true of all diseases of viscera in which 

 pain figures conspicuously as a subjective symptom. To find the possible 

 somatic area where pain may occur, use figure 185 according to the following 

 steps : (<?) Where is the diseased organ located ? (K) Are the organs in this 

 area supplied by the cardiac, solar, or hypogastric plexus ? (c) At what place 

 do the sympathetic nerves forming the plexus, supplying the organ under 

 consideration, communicate with the somatic or spinal nerves? (4) What 

 becomes now of the spinal nerves given off where the sympathetic communicate 

 with them? Do these spinals form either the cervical, brachial, lumbar, sacral, 

 or coccygeal plexus, or do they form the thoracic nerves? (5) Trace out the 

 distribution of the spinal nerve, and you will have the somatic route pursued by 

 pain originating in the sympathetic area. The steps then would be : () sympa- 

 thetic area ; (6) communicating branches with the somatic nerves ; (<) transfer 

 centre in the cord, (d) Somatic distribution of nerves over which pain may travel. 

 Articulations may be involved in reflex pain. In the case of pain in the little 

 finger incident to valvular lesion, the student must be prepared to answer the 

 question, Where may the pain have been in this same valvular lesion, aside from 

 in the skin of the little finger and one-half the ring finger ? (6) The same nerve, 

 the ulnar, also sends sensory branches to every articulation, which any of the 

 muscles supplied by its motor filaments moved or assisted in moving ; hence in 

 the elbow or any of the following joints a reflex pain, darting and stabbing in 

 character, may be a sequel of valvular heart lesions. (7) Distribution of cranial 

 sympathetic nerves ; (8) Distribution of external carotid sympathetic nerves ; 

 (9) Distribution of cardiac sympathetic nerves; (10) Distribution of solar 

 sympathetic nerves ; ( i i ) Distribution of hypogastric sympathetic nerves. 

 18 



