GENERAL ANATOMY,
APPLIED TO
PHYSIOLOGY AND MEDICINE;
BY XAVIER BICHAT,
PHYSICIAN OF THE GREAT HOSPITAL OF HUMANITY AT PARIS, AND
PROFESSOR OF ANATOMY AND PHYSIOLOGY.
Translated from the French.
BY GEORGE HAYWARD, M.D.
FELLOW OF THE AMERICAN ACADEMY OF ARTS AND SCIENCES,
AND OF THE MASSACHUSETTS MEDICAL SOCIETY.
_IN THREE VOLUMES._
VOLUME III.
_BOSTON_:
PUBLISHED BY RICHARDSON AND LORD.
J. H. A. FROST, PRINTER.
1822.
DISTRICT OF MASSACHUSETTS, _to wit_:
DISTRICT CLERK'S OFFICE.
BE IT REMEMBERED, that on the seventeenth day of April, A.D. 1822,
in the forty-sixth year of the Independence of the United States of
America, _Richardson & Lord_, of the said District, have deposited
in this office the title of a book, the right whereof they claim as
proprietors, in the words following, _to wit_:
"General Anatomy, applied to Physiology and Medicine; by Xavier Bichat,
Physician of the Great Hospital of Humanity at Paris, and Professor of
Anatomy and Physiology. Translated from the French, by George Hayward,
M. D. Fellow of the American Academy of Arts and Sciences, and of the
Massachusetts Medical Society. In three Volumes. Volume III."
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JOHN W. DAVIS,
_Clerk of the District of Massachusetts._
MUSCULAR SYSTEM OF ORGANIC LIFE.
This system is not as abundantly spread out in the economy as the
preceding. The whole mass which it forms, compared with the whole of
the other, which is more than one third of the body, presents in this
respect a very remarkable difference. Its position is also different;
it is concentrated, 1st, in the thorax, where the heart and œsophagus
belong to it; 2d, in the abdomen where the stomach and intestines are
in part formed by it; 3d, in the pelvis where it contributes to form
the bladder and even the womb, though this belongs to generation, which
is a function distinct from organic life. This system then occupies
the middle of the trunk, is foreign to the extremities, and is found
far from the action of external bodies, whilst the other superficially
situated, forming almost alone the extremities, seems, as we have said,
almost as much destined in the trunk to protect the other organs, as
to execute the different motions of the animal. The head contains no
part of the organic muscular system; this region of the body is wholly
devoted to the organs of animal life.
ARTICLE FIRST.
OF THE FORMS OF THE MUSCULAR SYSTEM OF ORGANIC LIFE.
All the muscles of the preceding system take in general a straight
direction. These are all on the contrary curved upon themselves; all
represent muscular cavities differently turned, sometimes cylindrical
as in the intestines, sometimes conical as in the heart, sometimes
rounded as in the bladder, and sometimes very irregular as in the
stomach. No one is attached to the bones; all are destitute of
tendinous fibres. The white fibres arising from the internal surface of
the heart, and going to be attached to the valves of its ventricles,
have by no means the nature of the tendons. Ebullition does not easily
reduce them to gelatine; desiccation does not give them the yellowish
appearance of these organs; they resist maceration longer than them.
It is in general a great character that distinguishes the muscular
organic system from that of animal life, that it does not arise from,
nor terminate in fibrous organs. All the fibres of this last are
continuous either with tendons, or aponeuroses or fibrous membranes.
Almost all those of the first go on the contrary from the cellular
texture, and return to it after having run their course. I at first
thought that the dense and compact texture which is between the mucous
membrane and the fleshy fibres of the intestines, the bladder, the
stomach, &c. was an assemblage and net-work of many small tendons
corresponding to these fibres, and interwoven in the form of an
aponeurosis; the density of this layer deceived me at first view.
Ebullition, maceration, and desiccation have since taught me, that this
layer, completely foreign to the fibrous system, should be referred, as
Haller has said, to the cellular, which is only more dense and compact
there than elsewhere. It is this layer, which I have designated, in
the cellular system by the name of the sub-mucous texture. Many fibres
of the system of which we are treating appear to form an entire curve,
which is not crossed by any cellular intersection; some layers of the
heart exhibit this arrangement, which is in general very rare; so that
there is almost always an origin and termination of the fibres, upon an
organ of a nature different from their own.
We can hardly consider in a general manner the forms of the system of
which we are treating; each organ belonging to it is moulded upon the
form of the viscus to the formation of which it contributes. In fact,
the organic muscles do not exist in distinct fasciculi, like those of
animal life; all, except the heart, form but a third, a quarter and
often even less in the structure of a viscus.
The greatest number has a thin, flat and membranous form. There are
layers more or less broad, and hardly ever distinct fasciculi. Placed
at the side of each other, the fibres are rarely one above another;
hence it happens that occupying a very great extent, these muscles form
however a very small volume. The great gluteus alone would be larger
than all the fibres of the stomach, the intestines and the bladder, if
they were united like it into a thick and square muscle.
ARTICLE SECOND.
ORGANIZATION OF THE MUSCULAR SYSTEM OF ORGANIC LIFE.
The organization of the involuntary muscles is not as uniform as that
of the preceding. In these all is exactly similar excepting the
differences of the proportion of the fleshy fibres to the tendinous,
of the length of the first, of the prominence of the fasciculi,
of their assemblage into flat, long or short muscles; in whatever
place we examine them, their varieties are in their forms and not in
their texture. Here on the contrary, there is in this texture marked
differences; the heart compared with the stomach, the intestines with
the bladder are sufficient to convince us of this. It is by virtue of
these different textures, that the contractility and sensibility vary
as we shall see in each muscle, that the force of the contraction is
not the same, and that life is different in each, whilst it is uniform
in all those of animal life. We shall now consider in a general manner
the organization of the involuntary muscles.
I. _Texture peculiar to the Organization of the Muscular System of
Organic Life._
The organic muscular fibre is in general much finer and more delicate
than that of the preceding system; it is not brought into as thick
fasciculi. Very red in the heart, it is whitish in the gastric and
urinary organs. Besides, this colour varies remarkably. I have observed
that sometimes maceration renders it of a deep brown in the intestines.
This fibre never has one single direction, like that of the preceding
muscles; it is interlaced always, or found in juxta-position in
different directions; sometimes it is at a right angle that the
fasciculi are cut, as in the longitudinal and circular fibres of
the gastric tubes; sometimes it is with angles more or less obtuse
or acute, as in the stomach, the bladder, &c. In the heart, this
interlacing is such in the ventricles, that it is a true muscular
net-work. From these varieties of direction, results an advantage in
the motions of these sorts of muscles, which, being all hollow can by
contracting diminish according to many diameters the extent of their
cavity.
Every organic muscular fibre is in general short; those which, like
the longitudinal of the œsophagus, the rectum, &c. appear to run a
long course, are not continuous; they arise and terminate at short
distances, and thus arise and terminate successively in the same
direction or line; no one is comparable to those of the sartorius, the
gracilis, &c. as it respects length.
We know the nature of their fibres no better than that of those of
animal life; but they appear nearly the same under the action of the
different reagents. Desiccation, putrefaction, maceration, ebullition,
exhibit in them the same phenomena. I have observed upon the subject of
this last, that once boiled, the fibres of both systems are much less
alterable by the acids sufficiently weakened. After being some time in
the sulphuric, the muriatic and nitric diluted with water, they soften
a little, but keep their original form, and do not change into that
pulp to which raw fibres are always reduced in the same experiment. The
last of these acids turns them yellow as before ebullition.
I have also made an observation as it respects the horny hardening
which is produced the instant ebullition commences; it is this, that it
is always the same whatever may have been the antecedent dilatation or
contraction of the fibres. The stomach which at death was so dilated
as to contain many pints of fluid, is reduced to the same size, all
other things being equal, as that which is contracted so as to be no
larger than the cœcum. Diseases have a little influence on the horny
hardening. The heart of a phthisical patient exhibited to me in the
same experiment this phenomenon much less evidently, than that of an
apoplectic.
The resistance of the organic muscular fibre is in proportion much
greater than that of the fibres of the animal muscular system.
Whatever may be the distension of the hollow muscles by the fluid which
fills them during life, ruptures hardly ever take place in them.
The bladder alone sometimes exhibits this phenomenon, which is
however very rare in it. In the great retentions of the urine, in
which ruptures take place, it is almost always the urethra that is
ruptured, and the bladder remains whole. We meet in practice with a
hundred fistulas in the perineum, coming from the membranous portion,
to one above the pubis. We find in authors many examples of rupture of
the diaphragm; we know of but few of the rupture of the stomach, the
intestines and the heart.
II. _Common Parts in the Organization of the Muscular System of Organic
Life._
The cellular texture is in general much more rare in the organic
muscles than in the others. The fibres of the heart are in
juxta-position, rather than united by this texture. It is a little more
evident in the gastric and urinary muscles. It is almost wanting in the
womb; thus these muscles are not infiltrated, like the preceding, in
dropsies; they never exhibit that fatty state of which we have spoken,
and which sometimes loads the fibres. I have not observed in these
fibres the yellowish tinge which the others often take, especially in
the vertebral depressions.
The blood vessels are very numerous in this system; they are found
in it even in greater proportion than in the other; more blood
consequently penetrates them. This fact is remarkable, especially in
the intestines, in which the mesenteric arteries distribute numerous
branches, over an extremely delicate fleshy surface. But I would remark
that this appearance is to a certain degree deceptive, as many of these
vessels only traverse the fleshy surface to go to the mucous membrane.
In the ordinary state they give to the gastric viscera a reddish tinge,
which I have rendered at will livid and afterwards brought back to
its primitive state, by shutting and afterwards opening the stop-cock
adapted to the wind pipe, in my experiments upon asphyxia.
The absorbents and exhalants have nothing peculiar in this system.
The nerves come to them from two sources; 1st, from the cerebral
system; 2d, from that of the ganglions.
Except in the stomach in which the par vagum is distributed, the nerves
of the ganglions predominate everywhere. In the heart, they are the
principal; in the intestines, they are the only ones; at the extremity
of the rectum and the bladder, their proportion is greater than that of
the nerves coming from the spine.
The cerebral nerves intermix with them, in penetrating the organic
muscles. The cardiac, solar, hypogastric, plexuses, &c. result from
this intermixture which appears to have an influence upon the motions,
though we are ignorant of the nature of this influence.
All the nerves of the ganglions which go to the organic muscles, do not
appear to be exclusively destined to them. A great number of filaments
belong only to the arteries; such is in fact their interlacing, that
they form, as we have seen, around these vessels a real nervous
membrane, superadded to their own, and exclusively destined to them.
I would compare this nervous envelope to the cellular envelope which
is also found around the arteries, and which is wholly distinct from
the surrounding cellular texture; thus it only has communications with
the nerves of the organic muscles, without being distributed to these
muscles. Besides as the nerves of the ganglions are always the most
numerous and essential in them, and as their tenuity is extreme, the
nervous mass destined to each is infinitely inferior to that which
is found in the voluntary muscles. The heart and the deltoid muscle
compared together, exhibit in this respect a remarkable difference.
ARTICLE THIRD.
PROPERTIES OF THE MUSCULAR SYSTEM OF ORGANIC LIFE.
Under the relation of properties, this system is in part analogous to
the preceding, and in part very different from it.
I. _Properties of Texture. Extensibility._
Extensibility is very evident in the organic muscles. The dilatation of
the intestines and the stomach by aliments, by the extrication of gas,
by the fluids that are found there, that of the bladder by the urine,
by injections that are forced in, &c. are essentially owing to this
extensibility.
This property is characterized here by two remarkable attributes; 1st,
by the rapidity with which it can be put into action; 2d, by the very
great extent of which it is susceptible.
The stomach and intestines pass in an instant from complete vacuity
to great extension. Artificially distended, the bladder becomes
immediately of a size treble, quadruple even of that which is natural
to it. It sometimes however resists, but this does not prove its
defect of extensibility; it is because the fluid injected irritates
it and makes it contract; the organic contractility in exercise, then
prevents the development of extensibility, as it sometimes cannot be
brought into action by stimulants in a muscle laid bare, because the
animal contractility in exercise in the muscle, forms an obstacle to
it. The muscles of animal life are never capable of this rapidity in
their extensibility, whether because they are intersected by numerous
aponeuroses which dilate but slowly, or whether because their layers
of fibres are very thick, two circumstances that do not exist in the
muscles of organic life. Hence a remarkable phenomenon that I have
observed in all cases of tympanites. When we open the abdomen of
subjects that have died in this state, without wounding the swelled
intestines, these immediately burst out, swell more, and occupy twice
as large a space as they were contained in in the abdomen; why? Because
the parietes of the abdomen being unable to yield in proportion to the
quantity of gas that is developed, this has been compressed in the
intestines during life, and expands immediately by its elasticity when
the cause of compression ceases. In dropsies in which the distension is
slow, the abdominal parietes enlarge much more than in tympanites. The
size of the abdomen would be double in this, if the extensibility of
the parietes was in proportion to that of the intestines.
As to the extent of the extensibility of the organic muscles, we can
form an idea of it by comparing the empty stomach which oftentimes
is not larger than the cæcum in its ordinary state, with the stomach
containing sometimes five, six and even eight pints of fluid; the
bladder contracted and concealed behind the pubis, with the bladder
full of urine from suppression, rising sometimes even above the
umbilicus; the rectum empty, with the rectum filling a part of the
pelvis in old people in whom the excrements have accumulated in it; the
intestines contracted with the intestines greatly distended.
It is to the extent of extensibility of the organic muscles and to the
limits placed to that of the abdominal parietes, that must be referred
a constant phenomenon that is observed in the gastric viscera; viz.
that in the natural series of their functions, they are never all
distended at the same time; the intestines are filled when the matters
contained in the stomach are evacuated; the bladder is not full of
urine in the digestive order, until the other hollow organs are empty,
&c. In general, that is an unnatural order in which all the organs are
distended at once.
There is for the organic muscles a mode of extensibility wholly
different from that of which I have just spoken; it is that of the
heart in aneurisms, and the womb in pregnancy. The first, for example,
acquires a size double, treble even sometimes in its left side, and yet
it increases at the same time in thickness. This size is not owing to
distension, but to a preternatural growth. The aneurismatic heart is
to the ordinary heart, what this is to the heart of the infant; it is
nutrition that makes the difference and not distension; for whenever
it is owing to this it diminishes in thickness as it increases in
extent; there is no addition of substance. Besides the aneurismatic
heart has not often the cause that distends it, for commonly in this
case the mitral valves allow a free passage to the blood; whilst when
they are ossified the left ventricle often remains in a natural state.
Moreover, the slow progress of the formation of aneurism proves that
it is a preternatural nutrition that has presided over this increase
of the heart. You would in vain then empty this organ of the blood
it contains, it would not contract and resume its dimensions, as the
inflated intestine does which we puncture to allow the air to escape.
In the womb there are two causes of distension; 1st, the sinuses
greatly developed; 2d, an addition of substance, a real momentary
increase of the fibres of the organ which remains as thick and even
more so than in the natural state. At the time of accouchement, the
sinuses immediately flatten by the contraction of the fibres; hence
the sudden contraction of the organ. But as on the one hand nutrition
alone can remove by decomposition the substances added to the fibres to
enlarge them, and as on the other, this function is exerted slowly,
after the womb has undergone the sudden contraction owing to the
flattening of its sinuses, it returns but gradually and at the end of
some time to its ordinary size. Extensibility is not then brought into
action in the womb filled by the fœtus, and in the aneurismatic heart;
these organs really become at that time the seat of a more active
nutrition; they grow preternaturally, as they have grown naturally
with the other organs; but these do not then experience an analogous
phenomenon, they become monstrous in comparison. The womb decreases,
because the motion of decomposition naturally predominates over that of
composition after accouchement, whilst it was the reverse before this
period. The aneurismatic heart remains always so.
These dilatations of the heart should be carefully distinguished from
those really produced by extensibility, as in the right auricle and
ventricle for example, which are found full of blood at the moment
of death, because the lungs which are weakened, not allowing it to
pass through them, compel it to flow back to the place from which it
came. There are but few hearts which do not exhibit in very various
degrees, these dilatations, which we have the power in a living
animal of increasing or diminishing at will, according to the kind of
death we produce. Two hearts are hardly ever of the same size after
death; many varieties are met with, and these depend more or less on
the difficulties which the blood experiences in the last moments,
in passing through the lungs. Hence why in the diseases of the
heart, there is no standard by which we can compare the morbid size,
especially if we examine the organ as a whole. In fact the distension
of the right side can give it an aneurismatic appearance, and a size
even greater than that of some aneurisms. If we examine the left side
separately, the error is more easily proved, because this side is
subject to less variations. But the principal difference consists
in the thickness. The power of contraction appears to increase in
proportion to this thickness, which arises from the substance added by
nutrition. It is this power which produces the great beating that is
felt under the ribs, the strength of the pulse, &c.
_Contractility._
It is in proportion to extensibility. It is often brought into action
in the ordinary state. It is in virtue of this property, that the
stomach, the bladder, the intestines, &c. contract, and acquire a size
so small compared to what they have when they are full. In general,
there is no muscle of animal life, which is capable of such extreme
contractions as those of organic life.
It should be remarked, however, that life, without having contractility
immediately dependant upon it, since the intestines, the stomach, and
the bladder contract after death when their distension is removed,
modifies it in a very evident manner. The causes even which alter
or diminish the vital forces have an influence upon it; hence the
following observation that all those accustomed to open dead bodies can
make. When the subject has died suddenly, and the stomach is empty, it
is much contracted; when, on the contrary, death has been preceded by a
long disease which has weakened its forces, the stomach, though empty,
remains flaccid, and is found but very little contracted.
We should consider the substances contained in the hollow muscles of
organic life, as true antagonists of these muscles; for they have
not muscles that act in a direction opposite to theirs. As long as
these antagonists distend them, they do not obey their contractility
of texture; when they are empty, this is brought into action. It is
not, however, upon this property that the mechanism of the expulsion
of matters from these organs turns, as aliments from the stomach and
intestines, urine from the bladder, blood from the heart, &c. It is
the organic contractility that presides over this mechanism. It is
difficult to distinguish these properties in exercise. One occasions
a slow and gradual contraction, which is without the alternation of
relaxation; the other, quick and sudden, consisting in a series of
relaxations and contractions, produces the peristaltic motion, those
of systole, diastole, &c. It is after the organic contractility has
procured the evacuation of the hollow muscles, that the contractility
of texture closes them. In death from hemorrhage from a great artery,
the left and even the right side of the heart send out all the blood
they contain; afterwards empty, they contract powerfully, and the
organ is very small. On the contrary, it is very large when much blood
remaining in its cavities, distends it, as in asphyxia. These are the
two extremes. There are, as I have said, many intermediate states.
The contractility of texture is, in the system of which we are
treating, in proportion to the number of fleshy fibres. Thus, all
things being equal, the rectum, when empty, contracts upon itself with
much more force than the other large intestines; the contraction of the
ventricles is much greater than that of the auricles, and that of the
œsophagus is much greater than that of the duodenum, &c. &c.
II. _Vital Properties._
They are almost in an inverse order of those of the preceding system.
_Properties of Animal Life. Sensibility._
The animal sensibility is slight in the organic muscles. We know
the observation related by Harvey upon a caries of the sternum that
laid bare the heart; they irritated, without its being felt by the
patient, this organ, which only contracted under the stimulant. Remove
the peritoneum behind the bladder of a living dog, and irritate the
subjacent muscular layer, the animal gives but few marks of pain. It
is difficult to make these experiments upon the intestines and the
stomach; their muscular coat is so delicate that we cannot act upon it
without at the same time stimulating the subjacent nerves.
It appears that the organic muscles are much less susceptible of the
feeling of lassitude, of which the preceding become the seat after
great exercise. I do not know however if in those to which many
cerebral nerves go, it does not take place; for example, when the
stomach has been for a long time contracted, it is probable that the
lassitude of its fibres, produces in part the painful sensation that
we then have, and which we call hunger, a sensation that should be
distinguished from the general affection that succeeds it, and which
becomes truly a disease, when abstinence has been too much prolonged.
We know that substances not nutritive then appease this sensation
without remedying the disease, when the stomach is filled with them.
I refer to the same kind of sensibility the anxiety and distress
which patients experience, in whom we keep the bladder in permanent
contraction by an open sound in the urethra, which transmits the urine
as fast as it falls from the ureters. This sensation does not resemble
that of hunger, because the sensibility of the bladder and that of
the stomach being different, their modifications cannot be the same.
Thus each of these two sensations is different from that of which the
muscles of animal life, for a long time contracted, become the seat. I
do not believe that the sensation of hunger belongs solely to the cause
I have pointed out, and which others have not spoken of; but it cannot
be denied that it has much part in it. Who knows if, after a fever in
which the action of the heart has been for a long time accelerated,
the weakness of the pulse which accompanies convalescence, is not a
sign of the lassitude in which its fleshy fibres are, on account of the
antecedent motion? We know the painful sensation of fatigue which the
stomach experiences after the contractions of vomiting.
_Contractility._
The animal contractility is foreign to the muscles of organic life.
To be convinced of this, we must recollect that on the one hand this
contractility always supposes the influence of the brain and the
nerves, to bring in play the action of the muscle, and that on the
other, the brain, in order to exert this influence, must be excited
by the will, by stimulants or by sympathies. Now none of these causes
acting upon the brain, the organic muscles cannot contract.
Every body knows that these muscles are essentially involuntary. If
some men have had the faculty of arresting the motions of the heart,
it is not upon this organ that the brain has acted; the action of the
diaphragm and the intercostals has first been suspended; respiration
has ceased for a time; then consequently the circulation.
If we irritate the brain with a scalpel or any other stimulant, the
muscles of animal life become convulsed; they are paralyzed if we
compress this organ. Those of organic life, on the contrary preserve in
both cases their natural degree of motion. The heart still continues
to beat, the intestines and stomach move some time after the cerebral
mass and spinal marrow have been taken away. Who does not know that
the circulation goes on very well in acephalous fœtuses; that after
the blow that has knocked down an animal, and rendered his whole
voluntary muscular system immoveable, the heart is still for a long
time agitated, the bladder rejects the urine, the rectum expels the
excrements, &c. the stomach even sometimes vomits up aliments? Opium,
which benumbs the whole animal life, because it acts especially
upon the brain which is the centre of it, which paralyzes all the
voluntary muscles, leaves the others unaffected in their contractions.
Intoxication produced by wine exhibits the same phenomenon. A man
staggers after drinking; his limbs refuse to carry him, and yet his
heart beats with force; his stomach often heaves and rejects the
surplus fluids it contains. All narcotic substances also produce this
effect.
If from experiments we pass to observations on the sick, we see that
all cerebral affections are foreign to the organic muscular system.
Wounds of the head with depression, fungi of the brain, effusions of
blood, pus and serum, apoplexy, &c. affect exclusively the voluntary
muscles, the action of which they increase, weaken or destroy. In the
midst of this general derangement of animal life, the organic remains
unaffected. The paroxysm of mania and malignant fever likewise proves
this fact. Who does not know that in this last the pulse is oftentimes
scarcely altered, that sometimes even it is slower?
Frequently in diseases of the head, there are spasmodic vomitings; the
action of the heart is accelerated in cerebral inflammations, &c. But
these are sympathetic phenomena which happen in the organic muscles, as
they do in all the other systems; they may not appear nor be developed;
a thousand irregularities are observed in their progress. Whereas
the contraction of the muscles of animal life by affections of the
brain is a constant, invariable phenomenon, which nothing disturbs,
and the development of which nothing prevents, because the means of
communication are always the same between the affected organ and the
one that moves.
If in the examination of the phenomena relative to the cerebral
influence upon the organic muscles, we follow an inverse order, that
is to say, that in the affections of these muscles we examine the
state of the brain, we observe the same independence; consider most
vomitings, the irregular motions of the intestines which take place in
diarrhœas, those especially which form the iliac passion, &c.; observe
the heart in the agitations of fevers, in the irregular palpitations
of which it becomes frequently the seat, &c.; in these derangements
of the organic muscles, you will very seldom find signs of lesions of
the cerebral organ; it is calm, while every thing is disordered in
organic life. Cullen thought that in syncope the action of the brain
ceased first, and that that of the heart was afterwards consequently
suspended. It is precisely the reverse in the greatest number of cases.
The heart, at first affected, ceases to act; now its action being
essential to that of the brain, whether from the motion it communicates
to it, or from the red blood it sends, the functions of this last are
suddenly suspended and the whole animal life ceases. This is remarkable
especially in the syncopes that arise from the passions, in those from
hemorrhages, polypi, great evacuations, &c. I refer upon this subject
to my Treatise upon Life and Death.
If from the influence of the brain we pass to that of the nerves, we
find new proofs of the absence of animal contractility in the organic
muscles. The most of these muscles receive, as we have seen, two
species of nerves, the one cerebral, the other from the ganglions.
The heart, the stomach, the rectum and the bladder are evidently
entered by the first species of nerves; now by cutting, or irritating
in any way the cardiac filaments of the par vagum, the heart
experiences no alteration from it; its motion is neither retarded, nor
accelerated. The division of both branches of the par vagum is fatal,
it is true, but not until after some days; and I doubt whether it is by
the heart that death commences in this case. The principal phenomena
consequent upon this division show a great embarrassment in the lungs,
a great difficulty of breathing; the circulation appears to be troubled
only in consequence.
The same nerves going to the stomach, the same experiment serves to
prove the cerebral influence upon this viscus. Now the division of that
of one side is usually nothing upon it; that of both soon produces a
remarkable derangement in it. But this derangement is wholly different
from that which follows the section of the nerve of a muscle of animal
life, which becomes suddenly immoveable, whilst that on the contrary
the stomach not communicating with the brain except by the par vagum,
seems to acquire in an instant an increase of power; it contracts
and hence the spasmodic vomitings that are almost always observed
during the two or three days that the animal survives the experiment,
vomitings that I have constantly noticed in dogs, and which Haller and
Cruikshank had before observed. It appears then from this, that though
the brain has a real influence upon the stomach, this influence is of
a nature wholly different from that which it exerts upon the voluntary
muscles. I would observe however that the irritation of one branch of
the par vagum, or of both, makes the stomach immediately contract,
as happens in a voluntary muscle when we irritate its nerve. It is
necessary, in order to make this experiment, to open the abdomen of a
living animal, and afterwards to irritate the eighth pair in the region
of the neck, so as to have in sight the organ that we make contract.
The bladder and the rectum appear to approximate the voluntary muscles,
in their relation with the brain, more than the stomach and the heart.
We know that falls on the sacrum, from which arises a shock of the
inferior part of the spinal marrow, produce retention of urine; that
they strike, as it were, this organ with the same paralysis as the
inferior extremities, which then also cease to move. Yet as the bladder
is very powerfully assisted in its functions by the abdominal muscles,
by the levator ani and other voluntary muscles which surround it, the
immobility of these muscles contributes much to the inability to
evacuate the urine. That which makes me think so, is that, 1st, the
irritation of the spinal marrow towards its inferior part which puts in
motion all the voluntary muscles of the inferior extremities and of the
pelvis, does not produce any effect upon this part. I have convinced
myself of this fact many times upon dogs and guinea-pigs. 2d. By
irritating the nerves coming from the sacral foramina and going to the
bladder, nerves that it is often very difficult to find, on account of
the blood in an animal recently killed, I have seen this muscle remain
immoveable. On the contrary all these nerves having been cut, the
injection of a fluid slightly stimulant makes it contract with force.
3d. In experiments upon living animals, as in surgical operations, the
violence of the pain which sometimes produces spasmodic contractions
of all the muscles of animal life, frequently occasions an involuntary
discharge of urine. Now in these cases it is not the bladder that
is convulsed; for if in an experiment this phenomenon takes place,
open the abdominal parietes, in an instant the flow of urine ceases,
because on the one hand the muscles of these parietes cannot act upon
the intestines and press them against the bladder, and because on the
other the levator ani which contracts and raises this organ, has no
resisting point against which it can compress it above. Observe in
fact that in strong jets of urine, the bladder is placed between two
opposite efforts, one superior, which is the gastric viscera pressed by
the diaphragm and the abdominal muscles, the other inferior, which is
especially the levator ani which acts by contracting from below above,
whilst the opposite effort acts from above below; now these two efforts
are evidently under the cerebral influence. I have very frequently
had occasion to observe the bladder full of urine in a living animal
whose abdomen was opened; I have never seen it contract with sufficient
violence to expel the fluid.
I do not deny but that the bladder, by the nerves it receives from the
sacral plexuses, is to a certain extent a voluntary muscle; but I say
that it is principally by forces accessory to its own and necessary
to its functions, that it is subjected to the will; that the animal
contractility is much greater in its functions than the sensible
organic contractility. How then is the urine retained in this organ,
or expelled from its cavity at will? In this way; when the urine falls
into the bladder, and is there on the one hand but a short time,
and on the other only in small quantity, it is not then an irritant
sufficiently powerful to produce the exercise of the sensible organic
contractility. The effort which the bladder makes is so small, that it
cannot overcome the resistance of the urethra, which being shut by the
contractility of texture, must be dilated by the impulse communicated
to the urine. In order to void this fluid, there must then be added
to the contraction of the bladder that of the surrounding voluntary
muscles; now the least effort of these muscles is sufficient to
overcome the resistance of the urethra. But if the urine is in great
quantity in the bladder, and it has acquired by remaining in it a
long time that deep colour which indicates the concentration of its
principles, then the irritation that it produces on the organ brings
powerfully into action the sensible organic contractility; the bladder
contracts, and in spite of the animal, there is an evacuation of urine.
In the rectum, in which the excrements have not a long canal, but only
a simple opening to pass, this is furnished with a sphincter which
is wanting in the urethra. This sphincter habitually closed must be
dilated by the impulse communicated to the excrements. When they are
in the rectum a short time and in small quantity, the sensible organic
contractility is not brought into action with sufficient power to expel
them; it requires the action of the neighbouring voluntary muscles.
If this action is not determined by the influx from the brain, the
excrements remain in the intestines; hence how, for some time, we
retain them at will. But as they increase in quantity, and become
more acrid by remaining and consequently more irritating, then the
sensible organic contractility strongly brought into action, empties
the intestine involuntarily. If the sphincter, which is voluntary, is
paralyzed, there will be incontinence, because no resistance is opposed
to the tendency of the rectum to contract, a tendency which though
feeble as long as it is but partly filled, is however always real.
From what we have said, it appears evidently that the bladder and
rectum, though receiving cerebral nerves, are yet less influenced by
the brain than it at first view appears, and that there is evidently
between them and the voluntary muscles a very great difference. They
are not mixt, as it is called; they approach the organic muscles
infinitely nearer than the others; I doubt even whether if no accessory
power acted with and compressed them, the mind could by the nerves
which come from the sacral plexuses, make them contract at will. I have
never seen an animal void his excrements when the abdomen was open.
Let us conclude from all that has been thus far said, that the cerebral
nerves which go to the organic muscles have upon them an influence
which by no means resembles that of the cerebral nerves going to the
muscles of animal life. I am ignorant moreover of the nature of this
influence.
All the organic muscles receive nerves from the ganglions, both the
preceding ones which are also penetrated by the cerebral nerves, and
the small intestines, and the cœcum, colour, &c. which are exclusively
pervaded by them. Now by cutting, tying or irritating in any manner
these nerves, by stimulating the ganglions from which they go, by
destroying or burning them with a concentrated acid or alkali, the
muscle remains in its natural state; its contractions are neither
accelerated nor retarded.
I have not been contented with ordinary agents in convincing myself
of the deficiency of real action of the nerves upon the organic
muscles; a fact, which all good physiologists have always admitted,
notwithstanding the opinions hazarded by some physicians who apply the
vague term of nervous influence to organs which are not susceptible of
it.
I have then employed galvanism, and I am convinced that it has very
little, almost no power, in putting into action muscular contractions
in organic life, whilst it is the most powerful agent in animal life.
I shall not here relate my experiments upon this subject; they will be
read in my Researches upon Death.
We can conclude from all that precedes, that the cerebral and nervous
influence upon the organic muscles is not known to us; that it does
not act as upon the voluntary muscles. It is however real to a certain
extent, since it is necessary that the nerves which enter into the
composition of these muscles should be of some use; but we are ignorant
of this use.
_Organic Properties._
The organic sensibility is strongly characterized in the muscles of
which we are treating. Before the sensible organic contractility is
developed in them, it is necessary that this should be put in action.
But as these two properties are not separated, as in their exercise
they always succeed each other, what we are going to say of sensible
organic contractility will apply also to the sensibility of the same
nature.
Insensible organic contractility or tone, exists in the muscular
system, to a degree necessary for its nutrition; but it does not
exhibit in it any thing peculiar.
It is the sensible organic contractility that is the predominant
property in this system, all the functions of which rest almost
entirely upon this contractility, as all the functions of the preceding
muscular system are derived as it were from the animal contractility.
We shall now examine more in detail this essential property, with
regard to which physiology owes so much to the illustrious Haller. We
can consider it in three relations; 1st, in the stimuli; 2d, in the
organs; 3d, in the action of the first upon the second.
_Of the Sensible Organic Contractility considered in relation to
Stimuli._
Stimuli are natural or artificial. The action of the first is continual
during life; upon them turn in part the organic phenomena; they place
in action the muscles, which without them would be immoveable; they are
as it were to these organs what pendulums are to our machines; they
give the impulse. The second can hardly have effect until after death,
or in our experiments.
_Natural Stimuli._
These stimuli are blood for the heart, urine for the bladder, aliments
and excrements for the gastric organs. Every organic muscle has a body,
which, habitually in contact with it, supports its motions, as every
animal muscle habitually in relation with the brain, borrows from it
its power of motion. The natural stimuli support the organs at the
same degree of mobility while they remain the same. All things being
equal on the part of the organs, the pulse does not vary, the digestive
periods continue for the same length of time, the intervals between
the excretion of urine are equal, whilst the blood, the chyle or the
urine exhibit no differences. But as these substances experience an
infinite number of varieties, the organs preserving the same degree of
sensibility, have yet frequent changes in their motion.
At the instant chyle enters the blood during digestion, the pulse
changes, because the heart is differently irritated. We observe the
same phenomenon under different circumstances; 1st, in re-absorptions
in which pus goes into the mass of blood; 2d, in the injection of
different fluids in the veins, injections that were so frequently
made in the last age, at the period of experiments upon transfusion,
and which I have also had occasion to make with other views which I
shall mention; 3d, in inflammatory diseases in which the blood takes a
peculiar character that is yet but little known, and which occasions
the formation of the pleuritic buff; 4th, in various other affections,
in which the nature of this fluid is remarkably altered; 5th, in the
passage of the red blood into the system with black blood. I have
observed that in putting a curved tube into the carotid of one side
and the jugular of the opposite of a large dog, so that one forces
blood into the other, the passage of the red blood into the veins is
not fatal like that of the black blood into the arteries; but there is
almost always at first an acceleration of the motions of the heart.
The influence of the degeneracy of the fluids in diseases has no doubt
been exaggerated; too frequent a source of morbid derangements has
been placed in this portion of the economy. But it cannot be denied,
that according to the different alterations that the fluids exhibit,
they may be capable of exciting differently the solids that contain
them. We know that in the same individual, and with the same mass of
aliments, digestion varies from one day to another in the duration of
its periods; that some aliments prolong and others accelerate it; that
some remain very long in the stomach, as it is said, and others as it
were only pass through it. Now in all these cases the organ remains
the same, the fluid only varies. According as the kidney secretes
urine more or less acrid and consequently more or less irritating, the
bladder retains it for a longer or shorter time. Such is oftentimes
its stimulating qualities, that the moment it comes into this organ
it is involuntarily rejected. Shall I speak of emetics and evacuants
by the intestinal canal, the effects of which are so variable? We
know that the words drastic, purgative, laxative, &c. indicate the
different degrees of the stimulating qualities which certain substances
introduced into the alimentary canal exhibit, degrees which are to be
considered abstractedly from those of the sensibility of the organs;
this in fact can be such, that a laxative may produce greater effects
than a drastic purge.
Not only the quality, but also the quantity of the fluids contained in
the organic muscles, has an influence upon their contractility. 1st.
The word plethora is certainly employed too loosely in medicine; but we
cannot doubt that the state which it expresses sometimes exists; now
the more blood there is in the heart, the more are its contractions
accelerated. 2d. I have many times made transfusion in dogs, whether
with a view to that alone, or in researches relative to respiration
and circulation. Now I have always observed, that by not opening a
vein, to empty the blood as fast as the external jugular receives it
(for I always choose this vein for the experiment) by thus producing
consequently an artificial plethora, I have, I say, always observed
that the motion of the heart was accelerated. I have even seen the
eye of a dog become bright and as it were inflamed; in others this
phenomenon has not been observed. 3d. We know that in running, in
which all the muscles by contracting press out from all sides the
venous blood contained in their texture, this which enters the heart in
abundance, makes it palpitate powerfully. 4th. There is not doubt but
that the quantity of urine and excrements as much and more than their
quality, is for the bladder and the rectum, a cause of involuntary
contraction. 5th. We know the serious consequences that arise from
giving emetics and cathartics in too large doses. 6th. A glass of tepid
water often does not produce vomiting when a pint will bring it on
powerfully, &c. &c.
_Artificial Stimuli._