ANTERIOR PRIMARY DIVISIONS OF THE SPINAL NERVES. 573 
emerges from the 
spinal canal through 
an intervertebral fora- 
men, and, proceeding 
outwards, is  distri- 
buted to thestructures 
on the lateral and 
anterior aspects of the 
body, including the 
limbs. Each nerve is 
joined near its origin 
by a gray ramus com- 
municans from the 
sympathetic gan- 
gliated cord; and in 
the case of certain 
thoracic, lumbar, and ACR. 
sacral nerves, the 
anterior primary divi- 
sion gives off'a delicate 
bundle of fibres, which 
forms the white ramus 
communicans of the 
sympathetic cord. 
That part of the spinal 
nerve which is distri- 
buted to the body wall 
and limbs may _ be 
termed somatic; the 
small white ramus 
communicans, imner- 
vating the structures 
in the splanchnic area, 
may be termed the \. a 
visceral or splanchnic 
part of the spinal 
nerve. The anterior 
primary divisions of 
the spinal nerves are 
pe 
IN. 
venrpa AXLE ae 
Anterlor 
Sul . Branches 
i,ateral 
BS 8 Branches 
a 
= 
(> 
77 
Lr] 
(7A 
only, in certain cases, Ni L.2.3 
distributed in a regu- 3 
lar segmental manner. M.C? ~ 
Except in the case of N 
~ 
the thoracic nerves, 
the anterior primary 
divisions arecombined 
into the three great Fic. 424.—THe DIsrRIBUTION OF CUTANEOUS NERVES ON THE FRONT OF 
plexuses—cervical, THE TRUNK. 
brachial, and lumbo- 0” one side the distribution of the several nerves is represented, the letters 
indicating their nomenclature. 
> 
‘ 
sacral, which renders 
: G.A, xreat icule aVcd 5. a S rtict eervica rve; §.C 8 ran 
their arrangement and ~“ Great auricular nerve; S.C, Superficial cervical nerve; §.CL, Supra 
clavicular nerves ; Ack, Acromial ; Cr, Clavicular ; Sr, Sternal ; T.2-12, 
distribution exceed- Lateral and anterior branches of thoracic nerves ; I.H, Ilio-hypogastric 
ingly complex. nerve ; a po ore ee CIRC, ae are of circumflex 
: nerve ; L.I.C, Lesser internal cutaneous nerve ; I.H, Intercosto-humeral ; 
A thoracic EESAICD I.C, Internal cutaneous ; M.S, Cutaneous branch of musculo-spiral nerve ; 
such as the fifth or E.C, External cutaneous nerves ; G.C, Genito-crural nerve ; M.C!*, Middle 
sixth, may be regarded cutaneous nerves ; I.C1, Branch of internal cutaneous nerve ; P, Branches 
of pudic nerve ; 8.Sc, Branches of small sciatic nerve. 
as a type to illustrate siete: ‘yar 
the mode of distribu- 2” the other pie a SEAS representation is given of dae areas supplied by 
z 4 the above nerves, the numerals indicating the spinal origin of the branches 
tion of the anterior of distribution to each area. 
ae 
