Sympathetic components of the Genito-femoral and obturator nerves in the rhesus monkey (Macaca mulatta).код для вставкиСкачать
SYMPATHETIC COlIPONENTS O F THE GENITOFEMORAL AND OUTURATOlZ NEBVliiS IiS THE RHESTTS YONKEY (M-ACACA XULA'I'TA) 8. ZUCKERMAN A E U H. S. B U R R Departnient of Physiology and S e c t i m o f Netiro-anatomy, Department of Anatomy, Pale U:,airersitg School of Medicine T\YO FIGURES Since the pioneer work 01 Gaskell (1883), aiid Langley (1894) it has been generally admitted that, in spite of the variability iii the orgaiiizatioii of the sympathetic iiervous system, a cliaracteristic patter11 may be recognized. This has been recently reaffirriiecl by Woollard ( '26 a, '26 b arid '33) in a study of the iiiriervation of blood vessels; lie has presented evidence that vaso-constrictor aiid vaso-dilator impulses to the vessels of the limbs are coiiveyecl almost exclusivelF bv fibers travcrsiiig the peripheral nerves. These fibers must of necessity pass from the sympathetic c h i n t o the somatic nerve throiqh the rami communicantes. The on]:exception t o the abore gciieralization is the aorta and the roots of its major branches. These vessels are supplied directly from the iierre plexuses surrounding the aorta. A variant of the above arrangemciit has recently heen discovered by one of us dnriiig the coarse of routine dissections of tlie rliesiis monkey. By cbaiicc there was discovered R definite liranch of the fifth lumbar s p q i a t h e t i c ganglion which traversed tlie fascia1 plane and close to the pelvic brim sent a branch t o join the obtarator nerve and a sceond branch t o be distributed to the tldoerititia of the extcriial iliac artery (fig. 1). The genito-femord, with wliicli it might have been coiif~mxl,wab clearly indica as a scparate trunk. 33 THE AVATOMICAL BECORD, T O T . 61, NO. 1 54 S. ZLTCIIETIMAN A N D H. S . BURR Following the original discovery, successive clissections uncovered an interesting series of variations from tlie normal to this particular extreme. It has loiig beru known that both the genitof(1moral and obturator nerves contain fibers wliidi a r e ultimately clistrihted to the ~.~;alls of blood vessels. These fibers reach the nerves from the sympathetic c*liain via the m m i (fig. 2 A ) . In a number of iiistxnces the simplest varinbiori from the normal was shown to he ail additioiial ramus from the fifth lumbar sympathetic ganglion joining the genito-femoral some distance peripheral to the emergence of the nerve froin the psoas muscle. Sometimes single, this connection may, on occasion, be double. T t is clear that this arrangement con sti tut es a direct con tinnatioii of the sympathetic iiervous system to tlie genitofemoral iicrve. A similar arraiigement is to be f o a n d in association with the obturator nerve. Herr (fig. 2 B) again clefinite branches h a r e been traced froin the fiflh 01Fig. 1 Pholograph of the left side of a disseclion nf n rlicsus mon1rt.y s h o w i n g tl:e aberrant branrh nf thc fifth sympathetic gangiion. P, pnoas muscle : C , genito-femoral nerve: 8, branch of fifth sympathetic! ganglion supplying the advrntitia of the extrrnal iliac artery ( I ) and anastoniosiiig with the oliturator n e n c (0). sixth lumbar. sympathetic ganglion to the ohturatoi- nerve. This suggests that sympathetic commuiiicatioii with tlie peripheral nerve may owur in addition t o thc usiial rami communicantes. Thcse dissections iriclicatc very clearly that vascular branches from the sympathetic chain map be distributed to the genito-fenioral and ohtuuator iierves by trunks addi- N.OBTURJXTORIUS Fig. 2 A. ,4 diagram rctlrawri from H a i t m a n a n d Stmus, showing thc normal relations betwccri the sympathetic. chain and t h e lunihnr and sacral plcxuscs. B. il variation froin the normal, sliouiiig extra branches from th e fifth sympathetic ganglion t o the gcnito femoral and ohturator nerves. (". A diagramatic recon strurtion of the relationships shown in the photograph of figure 1. tioiial t o thc rami communicantes. It is not surprising, therefore, to firid in a number of iiistances that these vascular braiichcs, instcad of running with cert ain somatic braiiches of the lumbar plexus, reach their ultimate destination directly, without traversing any of the liimhar somatic nerves. It is interesting t o note that all of these aberrant trunks take origin from the fifth lumbar sympathetic ganglion, that they may join a ) tlie gcnito-femoral or b ) the obturtator or c) pass directly to the periphery without joining either the genitofemoral or the ohturator (fig. 2 C). These findings are another demonstration of a well known fact that a growing axis cylinder may follour any one of a number of different paths t o reach its ultimate destination. COTCLUSION Dissections of the rliesus monkey have demonstrated that thc vascular branches of the lumbar sympathetic chair1 ma>reach blie walls of tlie perilheral blood vessels directly witliout joining or rnriniiig v i t h somatic nerves. These, in turn, may receive sympathetic contributions directly, as well a s hy w a ~of - the mini commuiiicaiites of thc spinal roots from which they take origin. LITERATURE CITED A Iiiblogrxphy Ha~mnra~, C'. G., %'OOLLA4RD, ( 3 0 1 frilly this field may b e found i n thc followjng papers: AND %I-. I,. h t 4 ~ 5 JR. , 1933 Thc Anatonly of the Rhcsus Monkey. Williams &- Wilkina, Baltimore. H. H., AND R. E. NORRISH 1083 The aiiatoriiy of the peripheral sympathetic ~ i c n o u sSJ btem. British. .T. of Surgrry, vol. 21, 110. 81, Ju1.y.