are directed from the base to the apex of the
ventricle; those on the anterior surface passing
obliquely downwards from left to right, those
on the posterior surface from right to left ;
they thus in general cross obliquely the direc-
tion of the muscular fibres of the ventricles,
and often also that of the blood vessels.
Where they cross the latter, especially in the
heart of the young ox, they appear to bifur-
cate, so as to enclose the vessel in a loop ;
and at this point there is frequently, as is re-
presented by Dr. Lee, a small enlargement
which occasionally contains ganglionic matter.*
In their course along the surface of the ven-
tricles, neighbouring filaments frequently unite,
there being here also small ganglionic enlarge-
ments. According to Dr. Lee there are dis-
tinctly visible on the anterior surface of the
* Dr. Lee, on the Ganglia and Nerves of the
Heart. Phil. Trans. 1849.
young heifer's heart about ninety of these
ganglia or ganglionic enlargements. The left
ventricle appears to be more 'abundantly sup-
plied with nerves than that of the right side :
on the former they can be traced, extending
from base to apex, on the surface of the
latter they generally extend but a little way
down, when they sink into the muscular
substance.
2. Plexus of the Thoracic Aorta. This con-
sists of delicate filaments which are derived
from the thoracic portion of the gangliated
chain of the sympathetic; several filaments also
pass between it and the cesophageal plexus.
Above, it is continued into the cardiac plexus,
from which it derives some branches,and below
it accompanies the vessel through the aortic
opening in the diaphragm, to terminate in
the coeliac plexus.
C. Abdominal Plexuses of the Sympathetic
The abdominal plexuses of the sympathetic
are larger and more numerous than those oc-
curring in any of the other cavities of the
body. They correspond in number with the
branches of the abdominal aorta, and accom-
pany them in their course to the different
viscera. From the plexuses occurring on the
larger arteries, off-sets pass, which form a
number of subsidiary plexuses upon the smaller
vessels. The chief abdominal plexuses are the
coeliac, superior mesenteric, renal, inferior mesen-
teric, and superior and inferior hypogastric
plexuses.
1 . The coeliac, solar, or epigastric plexus
is the largest of the plexuses of the sympa-
thetic. It is situated in the upper part of the
cavity of the abdomen, on both sides of the
aortic opening in the diaphragm, extending
across the anterior part of the aorta, and
is covered in front by the stomach. It sur-
rounds the coeliac axis, and extends down-
wards as far as the origin of the superior
mesenteric artery. It usually contains two
ganglia; these present a somewhat crescentic
form, and have on this account been termed
the semilunar ganglia. They are situated one
on each side of the plexus towards its upper
part, and are commonly surrounded by a num-
ber of smaller ganglia. The solar plexus
receives the splanchnic nerves, also some
branches from the posterior gastric plexus of
the pneumogastric ; it likewise receives fila-
ments from the plexus which has been de-
scribed as surrounding the thoracic aorta, as
well as others from the three or four upper
lumbar ganglia. The offsets from the plexus
present the same plexiform arrangement as
the plexus itself, and are named according to
the arteries which they accompany ; they are
the phrenic, or diaphragmatic, superior coro-
nary, hepatic, splenic, and renal plexuses.
(a) The diaphragmatic plexuses are two
in number, a right and left, and consist of
several delicate filaments derived from the
upper part of the semilunar ganglia. They
often present several small ganglionic en-
largements, and accompany the diaphragmatic
arteries, sinking with them into the muscular
SYMPATHETIC NERVE.
429
substance of the diaphragm, where they com-
municate with branches of the phrenic nerve.
(b) The superior coronary plexus accom-
panies the left coronary artery of the stomach,
along its upper border, and is distributed to
the anterior and posterior walls of the organ,
its filaments uniting with the branches sup-
plied by the pneumogastric nerves, chiefly
with those which are distributed to the
posterior wall of the stomach. It extends to
the pyloric orifice, where it joins branches of
the hepatic plexus.
(c) The hepatic plexus, of considerable
size, ascends along with the hepatic artery ; it
receives some filaments from the pneumo-
gastric nerve, and also communicates, as has
been already mentioned, with the superior
coronary plexus of the stomach. Branches
leave it for the duodenum and head of the
pancreas ; and others pass with the right gastro-
epiploic artery, along the greater curvature of
the stomach, forming the inferior coronary
plexus of the stomach. On entering the trans-
verse fissure of the liver, the hepatic plexus
divides into a right and a left portion, which
accompany the divisions of the hepatic artery
and vena portae, ramifying upon them an off-
set from the hepatic plexus passes to the
gall-bladder, along with the cystic artery.
(rf) The splenic plexus surrounds the
artery of the same name, passing with it and
its branches to the spleen. Offsets pass from
the splenic plexus to the pancreas, and to the
stomach, which form the pancreatic and left
gastro-epiploic plexuses.
2. The superior mesenteric Plexus appears as
a prolongation downwards of the cceliac
plexus, and is the largest of the offsets fur-
nished by it: it also receives some filaments
from the right pneumogastric nerve. It sur-
rounds the superior mesenteric artery, form-
ing for it a clo^e plexiform sheath, and sends
offsets along its branches, which accompany
them as they pass between the layers of the
mesentery to the duodenum, small intestine,
ccecum, and ascending and transverse colon.
The highest of these unite with the nerves
which pass along the pancreatico-duodenal ar-
tery, while those which are distributed to the
transverse colon communicate with the nerves
derived from the inferior mesenteric plexus.
The nerves which accompany the arteries to
the intestines present at first a plexiform
arrangement but in their course through the
mesentery, several of them are seen to run
alongside the vessels, sometimes separated a
short distance from them. Communicating
branches pass between them in the same way
as between the arteries. On reaching the
intestine they enter it at the part where the
mesentery is attached, and dividing into finer
twigs, soon disappear in the substance of its
coats. Many appear to become lost in the
muscular coats, while some may be traced
through these, ending apparently in the mu-
cous coat, or in the sub-mucous cellular
tissue.
3. Renal Plexuses. The right and left renal
plexuses are formed by branches which pro-
ceed from the coeliac and superior mesenteric
plexuses, and likewise derive filaments from
the aortic plexus. In their course along the
renal arteries they receive filaments, which
are sent offfrom the smaller splanchnic nerves,
and others from the superior lumbar ganglia.
Several small ganglia are present in the nerves
of the renal plexus. They divide along with
the branches of the renal artery, each arterial
branch being generally accompanied by two
nervous twigs. From the renal plexus fila-
ments are sent off, which, with others derived
from the cceliac and phrenic plexuses, form the
supra-renal plexus destined for the supply of
the supra-renal capsule.
4-. Spermatic Plexuses. The right and left
spermatic plexuses consist of some delicate
nervous filaments, which are derived from the
renal plexus. As they pass downwards with
the spermatic arteries, they receive some ad-
ditional filaments from the aortic plexus, and
appear to give off several filaments to the
ureters ; in their course to the testes they are
connected with the nerves which accompany
the vas deferens. In the female they are dis-
tributed to the ovaries and uterus.
5. The acrtic plexus, situated along the abdo-
minal aorta, and extending from the superior
to the inferior mesenteric arteries, consists of
filaments derived from the superior mesenteric
and renal plexuses. In its course downwards
it also receives branches from the lumbar gan-
glia : it terminates in the inferior mesenteric
and superior hypogastric plexuses, and also,
as has been already stated, contributes to the
formation of the spermatic plexus.
6. Inferior Mesenteric P/exus. The inferior
mesenteric plexus, formed by the left lateral
portion of the aortic plexus, is less dense and
less distinct than the superior plexus of the
same name: its fibres present, however, the
same whitish aspect and firm consistence, and
sometimes have small ganglionic enlargements
developed upon them. It accompanies the
inferior mesenteric artery, dividing along with
it, and forming secondary plexuses around its
branches, which pass with them to the de-
scending colon, sigmoid flexure, and upper
half of the rectum. Above, the branches of
the inferior mesenteric plexus form communi-
cations with those derived from the superior
mesenteric, and below, with others derived
from the superior hypogastric plexus of the
left side.
7. Hypogastric Plexus. The hypogastric, a
single plexus, situated in front of the fifth
lumbar vertebra and promontory of the sacrum,
between the two common iliac arteries, pre-
sents an irregularly quadrilateral and flattened
aspect. Nervous branches, about twelve in
number, pass down to it on each side from
the aortic plexus, and additional filaments are
derived from the lumbar ganglia. From the
plexus small offsets proceed along the common
iliac arteries, and a few join the hemorrhoidal
filaments derived from the superior mesenteric
plexus : it then divides into a right and left
430
SYMPATHETIC NERVE.
portion, which are continued forwards along
the sides of the rectum, to form the inferior
hypogastric plexuses.
8. Inferior Hypogastric Plexuses. These
consist of a right and left plexus, formed in the
manner just mentioned : they contain several
small ganglia. Filaments are likewise sent to
them from the sacral ganglia, as well as from
two or three of the sacral nerves. These
plexuses are situated upon the sides of the
rectum, the plexuses of opposite sides being
united by cross branches. From the plexus
proceed the following branches. () Some
hsemorrhoidal branches : these are termed the
inferior haemorrhoidal nerves ; they are very
delicate and unite with the superior hemor-
rhoidal branches derived from the inferior
mesenteric plexus, and go to supply the rec-
tum. (6) Vesical plexus . The nerves proceed-
ing to this plexus come from the lower and
anterior portion of the inferior hypogastric
plexus, and pass to the sides and lower part
of the bladder. The nerves are most numerous
near the neck of the organ, and have several
minute ganglia developed upon them. From
the neck numerous branches pass upwards on
the sides of the bladder, and are chiefly dis-
tributed to its muscular coats ; a few, however,
may be traced through the muscular to the
mucous coat. From the vesical plexus, fila-
ments are given off which pass to the vesiculae
seminales, around which they form a plexus ;
others pass to the vas deferens and ramify
around it, communicating on the spermatic
cord with the nerves of the spermatic plexus,
while a third portion passes to the prostate
gland. The branches which pass to the latter
are of considerable size, and form connections
with the plexus around the vesiculae seminales.
Some of the branches sink into the substance
of the gland, others are continued forwards
to the erectile tissue of the penis, constituting
the so-called cavernous nerves, or cavernous
plexus. From these branches are distributed
to the membranous portion of the urethra.
They then continue forwards, passing beneath
the arch of the pubis to the root of the penis.
By Miiller*, they are divided into nervi caver-
nosi minores, and nervus cavernosus major.
The former penetrate the cms of the corpus
cavernosus penis, and spread out upon the
cells of the erectile tissue : the latter runs
along the dorsum of the penis between the
dorsal artery and vein. About the middle of
the penis it divides into a number of branches
and forms communications with the dorsal
branch of the pudic nerve : some of the
branches accompany the dorsal vessels and
unite with those of the opposite side; the
greater portion, however, penetrate the corpus
cavernosum and are distributed to its sub-
stance.
9. Uterine Plexus. The nerves destined for
the supply of the uterus are derived from the
upper and posterior part of the inferior hypo-
gastric plexus, and also from the superior
* Ueber die organisehen Nerven der erectilen
mannlichen Geschlechts-organe. Berlin, 1836.
plexus of the same name. They pass between
the folds of the broad ligament in company
with the uterine vessels ; before reaching the
uterus, however, the greater portion of them
separate from the vessels, and are distributed
to the substance of the neck and body of the
organ. The portion derived from the superior
hypogastric plexus appears to be chiefly dis-
tributed to the fundus of the organ : a fila-
ment also passes, according to Dr. Beck*,
from the ovarian artery to the fundus
of the uterus. Besides the branches above
mentioned there are others, according to
Dr. Beck, derived also from the hypogastric
plexus, which assume a plexiform arrange-
ment around the vessels, and are characterised
by the presence of several minute ganglia.
Fig. 280.
Small ganglion from the posterior wall of the cervix
of an impregnated uterus of the Cow.
MINUTE ANATOMY. The branches of the
sympathetic nerve present to the naked eye
certain characters which, more or less, dis-
tinguish them from the proper cerebro-spinal
nerves. They have a dull greyish -white ap-
pearance, different from the white shining
aspect which characterises the nerves belong-
ing to the other class. This appearance is
better marked in some parts of the nerve than
in others, and is best seen in the branches
which accompany the blood-vessels. By
Valentin this gray appearance of the sym-
pathetic nerves was attributed to the presence
of the ganglionic corpuscles : this, however, as
Remak observed, cannot be the case, inas-
* On the Nerves of the Uterus.
1846.
Phil. Trans.
SYMPATHETIC NERVE.
much as the ganglionic corpuscles are not dis-
tributed throughout the whole extent of the
nerve, but are confined to certain limited parts.
Remak believed it to be due to the presence of
structures termed by him organic nerve fibres :
Volkmann and Bidder also believed it to be
owing to a peculiar set of fibres, different,
Fig. 281.
1. Tubular nerve-fibres from the thoracic portion of
the sympathetic cord in Man.
2. Fibres of Remak (gelatinous fibres') and fine tubular
nerve-fibres, from the nerves of the spleen in the
Sheep.
however, from those of Remak. Whether it
be due to the fibres of Remak or not, it seems
to be, at least, best marked in those branches
of the sympathetic in which these fibres are
most abundant. The sympathetic also differs
from the cerebro-spinal nerves in consistence
as well as in its appearance, being much softer
and more readily torn across than the latter.
This may be partly due to the want of the
strong distinct fibrous sheath possessed by the
latter, and partly also to a difference in the
character of the nerve fibres themselves. The
nerve fibres of the sympathetic are moreover
not arranged into distinct fasciculi, but lie
together imbedded in a mass of fibrous tissue
which accompanies them, serving the purpose
of a sheath.
As regards the constituents of the sympa-
thetic nervous trunk, when a portion of one
of the main cords is examined with a power
of 250 diameters, it is found to be composed
of the following elements: 1st. Tubular nerve
fibres ; 2nd. Structures which present a homo-
geneous flattened appearance, and contain a
number of oval nuclei imbedded in them at
intervals ; and, 3rd. a quantity of white fibrous
tissue.
The tubular nerve fibres which are present
in the sympathetic, differ much in point of
breadth from one another. Some of them
measure about ^-^ to -^L- of an inch in
diameter : their contents present the arrange-
ment of double contour and axis cylinder
which characterise the fibres occurring in the
cerebro-spinal nerves. Besides these fibres
there are others present which have also the
character of the tubular fibre, but are much
finer, measuring only from the 9 a * B to the
431
of an inch. They present distinct
margins, but have a paler aspect than the
above, and do not possess the double contour
which is seen in the broader tubular fibres,
and many of them often have a tendency to
the formation of varicosities. When running
in bundles they have, according to Volkmann*
and Bidder, who first called attention to their
anatomical characters, a yellowish grey hue
instead of the white pearly aspect of the
cerebro-spinal nerves. Sometimes the two
sets of fibres are intermingled and run side by
side with each other, at other times they run
in bundles more or less distinctly separated.
The number of fine fibres which are present
much exceeds that of the broader or coarser
variety. The two classes of fibres do not, how-
ever, appear to be distinctly marked off from
one another, there being present fibres which
possess partly the characters of the one and
partly those of the other. When one of the
finer variety is examined at the same time with
one of the coarser variety, and the two com-
pared, the points of distinction are sufficiently
Fig. 282.
Broader, or animal, and finer, or sympathetic, pri-
mitive nerve-fibres, from the common trunk of the
vagus in the Frog. (Bidder and Volkmann.}
marked, but a gradual transition from the fibres
belonging to the one set to those belonging to
the other may, in some parts of the sympa-
thetic, generally be traced. The finer the
nerve tubules are, the less distinctly do their
contents appear to be separated into central
portion or axis cylinder, and white substance
of Schwann.
2. In regard to the structures No. 2. which
have been mentioned as occurring in the sym-
pathetic, Remakf , their discoverer, describes
* Die Selbstandigkeit des sympathischen Xer-
vensystems von F. H. Bidder und A. W. Volk-
mann, Leipzig; 1842 ; p. 19. et seq.
t Observations Microscopicae, &c. Berol, 1838.
6. 13.
432
SYMPATHETIC NERVE.
them as being destitute of a sheath, naked,
transparent, almost gelatinous, as presenting
a number of longitudinal streaks, and as break-
ing up into delicate fibrils, which in their course
present oval dilatations or swellings, and have
moreover a number of round or oval cor-
puscles arranged upon them at intervals-
Apparently, the same structures have been
described by Henle under the name of " gela-
tinous fibres." According to him they are
flat homogeneous fibres, measuring from the
0-002'" to the 0-003'" in diameter, and cha-
racterised by the presence of numerous nuclei,
some round, others oval, their long diameter
being directed in the longitudinal axis of the
fibre. They are dissolved by acetic acid, the
nucleus becoming at the same time more dis-
tinct. The fibres in question are well seen in
the branches of the sympathetic which go to
the spleen or kidney in the sheep or ox, as
well as in the trunk of the sympathetic nerve
itself. In the former situations they appear
as a more or less transparent, slightly granular,
pale mass, and marked by indistinct longitudinal
lines into fibres presenting a diameter of about
__i_th to ^oVo-th of an inch, and characterised
by the presence of round, oval, or elongated
nuclei. On the addition of acetic acid they swell
out, becoming perfectly transparent and in-
distinct, while at the same time the nuclei are
brought more clearly into view. When treated
with tartaric or citric acid, the effect produced
upon them is much the same : solution of
soda also causes them to swell out and be-
come indistinct, the nuclei being at the same
time also rendered more or less indistinct.
The nuclei generally measure about the ^gWth
to the ^-Jgth of an inch in length, and about
TPjVrrth to the 41 ^ nr th of an inch in breadth,
presenting the same characters and behaving
towards reagents in [the same manner as
the nuclei occurring in most other tissues.
They are much softer than the tubular fibres,
and are not easily separated from one another.
In some parts of the peripheral branches of the
sympathetic these fibres present a much smaller
diameter, measuring about ^^n^th of an inch,
are finer and distinguished with difficulty from
the white fibrous tissue present. In the nerve
they are placed parallel to one another, and are
seen, when the preparation is pressed between
the glasses, running along each side of the
tubular fibres, which latter seem to be im-
bedded amongst them. They differ from the
tubular nerve-fibres in their flattened ap-
pearance, want of distinct margin, and in the
effects produced upon them by reagents, but
are especially characterised by the presence
of their nuclei. They are most abundant in
the more grey-looking branches of the sym-
pathetic, and seem to be the cause to which
this appearance is chiefly owing. Sometimes
when one of the smaller filaments of the
sympathetic is examined, it seems to be en-
tirely composed of these fibres, no tubular
nerve fibres being at first seen ; solution of
soda, however, which, as has been stated,
renders the gelatinous fibres transparent, brings
into view more or fewer fine tubular fibres.
There can be no doubt that in many parts of
the sympathetic, especially in the branches
distributed to the arteries, the fibres of Remak,
or gelatinous fibres, make up the greater portion
of their constituents, the tubular nerve fibres
existing only in comparatively small numbers
Sometimes more or less grey and white
bundles of fibres may be seen running along-
side each other : such an arrangement is not
unfrequently seen in the branches of com-
munication between the sympathetic and the
spinal nerves. In such cases, while the white
chiefly or entirely consists of tubular nerve
fibres, the grey contains a large number of
gelatinous fibres, and always in addition to
these more or fewer fine tubular fibres.
The gelatinous fibres are present in dif-
ferent proportion in different parts of the
sympathetic : they appear to be more abundant
in the neighbourhood of the ganglia than in
other parts and in the larger peripherical
branches they also exist in considerable pro-
portion, but in the final distribution of these
they either do not exist at all or only in small
number. They appear to be more abundant
in the sympathetic of the higher animals than
in that of the lower vertebrata. In mammals
and birds they exist in considerable quantity:
in amphibia, according to Kolliker, they are
present but only in small proportion. In
some fish, as in the common Ray, the sympa-
thetic ganglia and branches contain a very
large proportion of structures which agree
with the fibres of Remak in some respects,
such as in their relation to the ganglionic
corpuscles and tubular nerve fibres, as well as
by the presence of a number of small oval
nuclei ; they differ from them, however, in
not being so much affected by acetic acid and
in being firmer : the number of tubular fibres
occurring in the sympathetic is very small
compared with the number of these struc-
tures.
3. The quantity of white fibrous tissue
present in the sympathetic trunk and branches
is generally considerable; the fibres are arranged
in the longitudinal direction for the most
part ; other fibres, which from their relation to
reagents appear to belong to the yellow elastic
tissue, encircle the nerve, binding together, as
it were, its constituents. After addition of
soda or acetic acid the circular fibres are
well seen ; at the parts where they occur
there is frequently observed a distinct con-
striction, the nerve being swollen out above
and below by the reagent applied.
With respect to the nerve fibres occurring
in the sympathetic, many of them present
undoubtedly the same characters as those
occurring in the nerves of the cerebro-spinal
system. It has been maintained that the
sympathetic also contains fibres which differ
in their anatomical characters from the fibres
of which the latter class of nerves are com-