THE NERVOUS SYSTEM. 215 
cords there are three pairs of cervical ganglia, thirteen pairs 
of thoracic ganglia, seven pairs of lumbar ganglia, and one 
or two pairs of sacral ganglia, in addition to two median 
unpaired sacral ganglia. 
In the cervical region the Pe 
sympathetic and vagus, or P\ 
tenth cranial nerve, are ae d 
bound in a common sheath \ bulla 
lying along the lateral aspect a ce 
of the carotid artery. One Rec 
or two centimeters craniad a 
of the first rib is the thyroid \ Mecar 
or middle cervical ganglion, - r 
whence the nerve proceeds S 
in two cords, enclosing the 
subclavian artery, to the 
esophagus 
Fic. 107. Cuter Part or Lert 
HALF oF SYMPATHETIC SYSTEM 
CRANIAD OF THE DIAPHRAGM. : 
Semidiagrammatic. - = 
5, 6, 7, 8, 9, and 10, Fifth, sixth, sf fame 
seventh and eighth cervical 19. <4 
nerves, and first and second + 
thoracic spinal nerves; a, the 
dorsal branch of the left vagus 
In; an, dorsal branch of the right P_ [be +56 | 
vagus; ax, common dorsal vagus . My 
formed by a and an; avb, ventral ; My p ig 
vagus; bc, cardiac branch of sg, i as, 
cr, carotid plexus; car, carotid heart |% 
artery; cm, rami  communi- i 
cantes; cp, cardiac plexus; dia, 
diaphragm; g, ganglia in the ; 
thoracic cavity; 1g, middle cer- “< 
vical ganglion; /g, portion of 
left lung; In, left vagus nerve; In 4 es 
nv, cranial nerve; pn, phrenic pn 
nerve; pp, pulmonary plexus; 3 
sn, sympathetic cord; sm, supe- eee, aj 
rior cervical ganglion; sb, left 
: ; ; avo 
subclavian artery; sg, stellate 
ganglion or inferior cervical; YX spin 
spm, splanchnic major nerve; dio 
vg, vagus ganglion; v, vagus 
nerve. 
Cached 
3 
S 
VS 
+ sympathetic cord, 
Ck 
