a a oY ee * J 
THE TENTH OR PNEUMOGASTRIC NERVE. 649 
to supply the mucous membrane 
covering the tonsil, the adjacent 
part of the soft palate, and the 
pulars of the fauces. Lingual 
branches supply the mucous mem- 
brane of the dorsal third and 
lateral half of the tongue, extend- 
ing backwards to the glosso-epi- 
glottidean folds and the front of 
the epiglottis. 
THE TENTH OR PNEUMOGASTRIC 
NERVE: 
The pneumogastric or vagus 
nerve (n. vagus) arises from the 
brain by numerous radicles at- 
tached to the front of the resti- 
form body of the medulla ob- 
longata, in series with the glosso- 
pharyngeal nerve above and the 
spinal accessory nerve below it 
(for deep connexions, see p. 478). 
Uniting to form a single trunk, 
the roots of the nerve pass out- 
wards to the jugular foramen, 
through which they emerge into 
the neck. 
In the jugular foramen the 
nerve occupies the same sheath of 
dura mater as the spinal accessory 
nerve, and is placed behind the 
glosso-pharyngeal nerve. Two 
ganglia are present on the trunk 
in this situation. The higher and 
smaller is the ganglion of the root 
(g. jugulare); the lower and larger 
is the ganglion of the trunk of the 
nerve (g. nodosum). 
In the neck the pneumogastric 
herve pursues a vertical course in 
front of the spinal column. It 
occupies the carotid sheath, lying 
between and behind the internal 
and common carotid arteries and 
the internal jugular vein. It enters 
the thorax behind the-large veins : 
on the right side, after crossing 
over the subclavian artery ; on the L 
left side, in the interval between Fic. 467.—THE DisrRIBUTION OF THE PNEUMOGASTRIC NERVE. 
the left common carotid and sub- Va.R, Va.L, Right and left vagi ; r, Ganglion of the root and 
clavian arteries. connexions with Sy, Sympathetic, superior cervical gang- 
RO eh onan tl bees ne lio ; G.Ph, Glosso- pharyngeal; Acc, Spinal accessory 
nt et vorax the ner es occupy nerve ; m, Meningeal branch: Aur, Auricular branch ; t, 
the Super1or and posterior media- Ganglion of the trunk and connexions with Hy, Hypo- 
glossal nerve ; Cl, C2, Loop between the first two cervical 
nerves; Sy, Sympathetic ; Ace, Spinal accessory nerve; Ph, Pharyngeal branch ; Ph.Pl, Pharyngeal plexus ; 
S.L, Superior laryngeal nerve ; I.L, Internal laryngeal branch; E.L, External laryngeal branch ; I.C, 
Internal, and E.C, External carotid arteries ; Cal, Superior cervical cardiac branch ; Ca2, Inferior cervical 
cardiac branch ; R.L, Recurrent laryngeal nerve ; Cas, Cardiac branches from recurrent laryngeal nerves ; 
(a4, Thoracic cardiac branch (right vagus) ; A.P.Pl, Anterior, and P.P.Pl, Posterior pulmonary plexuses ; 
Oes.Pl, (Esophageal plexus; Gast.R, and Gast.L, Gastric branches of vagus (right and left) ; Coe.Pl, 
Celiac plexus ; Hep.Pl, Hepatic plexus ; Spl. Pl, Splenic plexus ; Ren. Pl, Renal plexus. 
