sympathetically into action; thus the diaphragm, the intercostal and
abdominal muscles contract to produce sneezing from irritation of the
pituitary membrane, or cough from the irritation of the membrane of
the bronchia, or from that even of the surface of the stomach, which
produces stomachic coughs, which, as we know, have nothing to do with
affections of the chest. We know the general spasm that seizes all the
muscles the instant a foreign body passes between the mucous edges of
the epiglottis. Stones of the bladder and the urethra, by making the
cremaster contract sympathetically, produce retraction of the testicle.
Physicians might, I think, profit by the knowledge of these mucous
sympathies. In apoplexy, in which the bronchia is sometimes filled with
mucus that the patient cannot evacuate, the action of ammonia upon the
pituitary membrane produces the double effect, 1st, of stimulating the
brain as blisters do; 2d, of freeing, by the cough it occasions, the
surface of the bronchia, which being obstructed, is an obstacle to the
passage of the air.
Sometimes it is the animal sensibility that is put into action by an
affection of the mucous surfaces. The stone, that irritates that of the
bladder, causes an itching at the end of the glans penis. That of the
intestines being irritated by worms, an inconvenient itching is felt
at the end of the nose. Whytt has seen a foreign body introduced into
the ear, affect painfully the whole corresponding side of the head; an
ulcer of the bladder, produce every time the patient passed water, a
pain on the superior part of the thigh, &c. &c.
The sensible organic contractility is often sympathetically excited
by the affections of the mucous system. I might at first refer to
this subject what I have observed respecting the organic muscles,
almost all of which move from an excitement of a contiguous mucous
surface; but that is a natural phenomenon; there are many others that
are preternatural. A stone that irritates the internal surface of the
pelvis of the kidney produces vomiting, which is, as we know, produced
any time at will by an irritation of the uvula. The instant the semen
passes the urethra in coition, the action of the heart is commonly
accelerated. Tissot speaks of a stone which, being entangled in the
duct of Warton, produced a sympathetic discharge from the bowels. I
saw at the Hôtel Dieu two women, who, whenever they menstruated, and
the mucous surface of the womb was consequently in activity, could
retain the urine but a short time in the bladder, which contracted
involuntarily to expel it the moment it entered it. At ordinary times,
there was nothing peculiar in the evacuation of this fluid.
As to the sympathies of insensible contractility and of organic
sensibility, they take place when a mucous surface being irritated
towards the extremity of an excretory duct, the gland of this duct is
brought into action, when, for example, the saliva flows in greater
abundance by the action of sialagogues upon the extremity of the
Stenonian duct. Whenever there is a gastric derangement and the mucous
surface of the stomach consequently suffers, the surface of the tongue
is sympathetically affected; the glands situated under this surface
increase their action and hence that white mucous coat, that is
commonly called a foul tongue, which is a real sympathetic catarrh, but
which can however exist idiopathically. Here also is to be referred
the remarkable influence of the mucous system upon the cutaneous; thus
during digestion, in which the mucous juices pour out abundantly from
all sides into the stomach and the intestines, and in which the mucous
membranes of the gastric viscera are consequently in great action, the
fluid of insensible transpiration is lessened remarkably, according to
the observation of Sanctorius; it is in very small quantity three hours
after the meal, so that the action of the cutaneous organ is evidently
less energetic. Thus during sleep, in which all the internal functions
become more evident and are exerted to their utmost, and in which the
sensibility of the mucous membranes is consequently strongly developed,
the skin seems to be struck with a species of atony; it becomes cold
more easily, it allows less substances to escape from it, &c. To
these sympathies also can be referred many phenomena of hemorrhages.
We know with what facility the mucous surface ceasing, from any
accidental cause, to throw out blood, as happens so often on that of
the womb, another is immediately affected and discharges this fluid;
hence hemorrhages from the nose, the stomach, the chest, &c. from the
suppression of those of the uterus, &c.
_Passive Sympathies._
In many cases, the other systems being irritated, the animal
sensibility of this is brought into action. Among the numerous examples
of this fact, the following is a remarkable one. In many diseases in
which organs foreign to the mucous system are affected, we experience
a sensation of burning heat in the mouth, the stomach, the intestines,
&c. and yet the mucous surface, the seat of this sensation, does not
disengage more caloric than usual; we may be convinced of this by
placing the fingers in the mouth. This sensation is of the same nature
as that which we refer to the glans penis when there is a stone in
the bladder, as that which is experienced at the end of the nose from
worms in the intestines, &c. There is no material cause of pain, and
yet there is suffering. Thus in intermittent fevers we experience a
cutaneous shivering, though the skin may be as warm as usual; I would
observe in respect to this, that the mucous membranes are hardly ever
the seat of an analogous sensation of sympathetic cold, but it is
almost always a sensation of heat that the aberrations of the vital
forces produce in them. Whence arises this difference between them and
the cutaneous organs? I know not. I attribute also to a sympathy of
animal sensibility the great thirst which takes place in all the severe
affections of any part. In all great wounds, after severe operations,
in experiments on living animals, &c. we observe this thirst which
depends upon a sympathetic affection of the whole mucous surface that
extends into the mouth, the stomach and the œsophagus.
Animal contractility cannot be put sympathetically into action in the
mucous system, since it does not exist in it.
The same is true of the sensible organic contractility. It is possible
that sometimes the kind of motion we have noticed, and which resembles
this property, may be sympathetically excited; I know no example of it.
The insensible organic contractility is here very frequently in
sympathetic activity. It is the skin especially which exercises by
means of this property, a great influence upon the mucous system. 1st.
In hemorrhages of the mucous surface of the womb, the nostrils, &c.
a cold body applied to the skin in the neighbourhood, contracts this
surface and stops the blood. 2d. Who does not know that the production
of most catarrhs is often the sudden consequence of the action of
cold on the cutaneous organ? 3d. In various affections of the mucous
membranes, baths which relax and expand the skin, frequently produce
happy effects. 4th. When the temperature of the atmosphere benumbs
the cutaneous tone, that of the mucous system receives a remarkable
increase of energy. Hence why in winter and in cold climates, in
which the functions of the skin are very much diminished, all those of
this system increase in proportion. Hence the more evident pulmonary
exhalation, the more abundant internal secretions, a more active
digestion, more quickly performed and consequently an appetite more
easily excited. 5th. When on the contrary the heat of the climate
and the season relax and expand the cutaneous surface, the mucous
surface is in proportion contracted; in summer, at noon, &c. there
is a diminution of the secretions, of that of the urine especially,
a slowness in the digestive phenomena from a defect in the action of
the stomach and intestines, an appetite slow to return, &c. 6th. In
various general affections of the skin, certain portions of the mucous
membranes are almost always affected. In scarlet fever, the throat
most usually suffers sympathetically. This phenomenon is very common
in small pox. 7th. In the latter periods of organic affections of the
viscera, as in phthisis, diseases of the heart, enlargements of the
liver, cancers of the womb, &c. the mucous membranes are affected like
the serous surfaces. The kind of atony in which they then are, produces
a more copious flow of mucous juices in them which are altered, become
more fluid, &c.; hence the diarrhœas that are called colliquative,
which are then to the mucous surfaces, what dropsies are to the serous
ones; 8th. It is also to this atony that must be attributed the
pectoral hemorrhages which so frequently take place in the last periods
of organic diseases, in those of the heart especially. During the short
time that I have been at the Hôtel Dieu, there has already died more
than twenty patients whom I have opened, of these affections almost
forgotten by all practitioners before the time of Corvisart; I have
only observed four examples in which passive hemorrhage of the lungs
was not the precursor of death.
_Character of the Vital Properties._
From what we have thus far said, it is evident that the mucous system
is one of those of the whole economy, in which life is the most active.
Always in contact with substances that stimulate and irritate it, it is
as it were like the skin, in continual action. Yet the life is not the
same in all its parts; it undergoes in each remarkable modifications,
which no doubt depend on those we have pointed out in the organization
of this system, in the nature of its corion, in the arrangement of its
papillæ, in the distribution of its vessels and its nerves, in that of
its glands, &c.; for as we have seen, none of these essential bases of
the mucous system is everywhere arranged in the same manner. There is
an organization common to the system, and one peculiar to each of its
divisions. It is the same in regard to its life; there is a life common
to the system, and as many peculiar ones as there are parts to which it
is extended. We know how much the animal sensibility of the pituitary
membrane differs from that of the palatine, how powerfully the membrane
of the glans penis and the urethra is stimulated by the passage of the
semen which makes no impression upon any other mucous surface. The same
is true in regard to the organic sensibility and the contractility of
the same species. Each mucous surface, in relation with the fluid it is
accustomed to, would bear the others with difficulty. The urine would
be a stimulant for the stomach and the gastric juice for the bladder;
the bile that remains in the gall-bladder would produce a catarrh upon
the membrane of the nose, in the vesiculæ seminales, &c.
From these varieties in the vital forces of each division of the
mucous system, it is not astonishing that the diseases of this system
should also be very variable. Each has a general character, but this
is modified in each mucous surface. There is an order of symptoms
common to all catarrhs; but each has its peculiar signs, each has
its different products. The fluid from a pulmonary catarrh does not
resemble that from a nasal one; that coming from a urethral, vesical
catarrh, &c. is wholly different from that from an intestinal one.
These fluids exhibit in their morbid changes the same differences that
we have pointed out in their natural composition, differences which are
derived like them, from the different vitality of each portion of the
mucous system.
It is to these varieties of life and the vital forces that must be
referred also those of the sympathies. Each portion of this system has
a peculiar sympathetic action upon the other organs. The pituitary
alone being irritated produces sneezing. You would excite in vain the
extremity of the glans penis, the rectum, &c. you would never produce
vomiting as you do by stimulating the uvula.
An important remark should here be made in regard to the stomach. We
know that there is no organ which performs a more important part in the
sympathies than this. The least affection of this important viscus,
the least gastric derangement, spread over the whole animal economy a
painful influence; all the other parts feel it. I do not believe even
that there is any uneasiness more fatiguing and general than that which
we then experience in certain cases. The general weakness which takes
place in hunger almost instantaneously, is sympathetic; the alteration
of nutrition has not had time to produce it. The same is true with
regard to the sudden increase of the forces which results from the
contact of the aliments upon the mucous surface of this viscus, an
increase which cannot be attributed to the passage of the chyle into
the blood, which has not yet had time to take place.
I think the stomach owes this important part in the sympathies
principally to its mucous surface. In fact, 1st, its serous surface has
no connexion with it, since it is there of the same nature as in all
the rest of the peritoneum, besides in what is called inflammation of
the abdomen, and in which this serous surface is especially affected,
we do not observe such numerous sympathetic relations. 2d. The fleshy
coat appears to be the same as that of the whole intestinal canal;
why then should it have different influences? 3d. As it respects
blood-vessels and nerves of the ganglions, the stomach is nearly
organized like the rest of the alimentary tube. 4th. It has besides the
par vagum; but is this nerve alone capable of producing such numerous
phenomena? It can contribute to them; but certainly the peculiar
modifications which it experiences in the mucous surface, the peculiar
nature of this membrane contribute also much to it. No membrane is
organized like that of the stomach. Though we do not see perfectly
at first view its organic differences, reflection is sufficient to
convince us of them; thus on the one hand no one separates so great
a quantity of fluid, and on the other none furnishes one of a nature
analogous to that of the gastric juice.
ARTICLE FOURTH.
DEVELOPMENT OF THE MUCOUS SYSTEM.
I. _State of the Mucous System in the First Age._
The development of the mucous system follows in general the laws of
that of the organs to which it belongs. Early in the gastric apparatus,
later in the pulmonary and that of generation, it seems in its growth
rather to obey the impulse it receives, than to give one to what
surrounds it, an arrangement common to almost all the systems which
contribute to form the different apparatus. Observe in fact that there
is always in the growth certain parts to which all the others refer;
thus in the cerebral apparatus, the early size of the brain produces
that of the bones of the cranium, of the dura-mater, the pia-mater,
the arachnoides and the vessels; thus it is on account of the spinal
marrow, that the vertebral canal is so evident in the fœtus; thus
all the serous surfaces have a growth in proportion to that of their
respective organs, &c. &c. I would remark however that the early growth
of the systems which are only to follow that of the parts to which they
are destined, is only in the dimensions of length, breadth, &c. The
thickness most commonly does not correspond with these dimensions. Thus
the bones of the cranium though broader in proportion than those of the
pelvis in the fœtus, are not thicker. The extent of the dura-mater is
in proportion greater than that of the albuginea which belongs to the
same system; but the organization is no further advanced.
In the fœtus, the delicacy of the mucous texture is extreme, the
papillæ are hardly perceptible. But by carrying the hand over a mucous
surface, we feel there an extremely delicate velvet and such as is not
equalled by the finest velvet. The redness of this system is not then
as evident, because no doubt less blood penetrates it, as the various
functions which are afterwards to take place upon these surfaces, as
digestion, the excretions, respiration, &c. are but feeble or entirely
wanting. At this age, the quantity of blood seems to be in an inverse
ratio in the skin and in these surfaces. The mucous red is then like
the muscular, of a very deep tinge, often even livid, on account of the
nature of the blood circulating in the arteries. Then the adhesions
of the mucous texture to the subjacent cellular are less; those
especially of this last with the surrounding parts are very slight;
thus it is very easy to draw out whole the internal portion of the
intestines of the fœtus, from the external covering that contains it,
so as to see two cylindrical canals, one of which is muscular and
serous, the other cellular and mucous. The stretching destroys in
this experiment all the valvulæ conniventes, and the small intestines
are as smooth on the interior as the large, in the canal artificially
extracted. If we subject this canal to ebullition, much more scum
arises from it than in the adult; this scum is white and never green.
The crisping that takes place a little before the first boiling,
diminishes more in proportion the length of the canal, and consequently
appears to be stronger.
At birth, when respiration and digestion suddenly commence, the
secretions increase, the mucous system acquires a remarkable degree of
activity. It is instantly excited powerfully by the many new substances
with which it is in contact. It is by it and by the cutaneous system
that bodies foreign to ours then immediately stimulate it, and so
much the more efficaciously, as the double surface which receives the
excitement is not accustomed to it. Then the red blood which penetrates
the mucous system, gives it an increase of energy and sensibility,
which renders it still more proper to receive impressions. Thus the
mucous juices which till then stagnated upon their respective surfaces,
without fatiguing and irritating them, are suddenly for them, on
account of their increase of sensibility, stimulants which excite them,
and force the subjacent muscles to contract. Then the urine becomes for
the bladder a cause that promotes the contraction of it. A few instants
after birth, all the openings in which the mucous membranes begin, open
and permit to escape the meconium, the urine and all the mucous juices.
This internal and general shock that empties all the mucous cavities,
renders them fit to become the seat of the great functions which are
soon to take place in them.
When all the internal functions are in activity, the mucous surfaces
experience no more sudden changes, analogous to that of which I have
spoken. They grow like the other viscera in a slow and insensible
manner; they preserve for a long time their original softness, which is
remarkable, especially in the nose, the stomach, &c. and which during
lactation, is not adapted in the infant, to the solid substances with
which the adult is nourished. Is this softness the cause of the mucous
affections which are in general so common at that age? We know that
then the mucous juices abound; the pituitary membrane is more moist;
the stomach and intestines are frequently affected with a species of
catarrh which is the cause of the looseness that we have so often to
combat in infancy. The membrane of the bronchia is also frequently
diseased. The two extreme ages of life resemble each other by the
abundance of the mucous juices secreted upon their respective mucous
surfaces.
In youth the mucous system is in very powerful action. The active
hemorrhages of this system are very frequent at this age; those of
the nose, the bronchia and even the stomach often take place; those
of the portions of this system, subjacent to the diaphragm, are then
less common. Observe that in man, hemorrhages of the gastro-pulmonary
surface are infinitely more frequent than those of the genito-urinary
surface, which on the contrary, are much more numerous in woman in whom
one of them is natural to a part of this surface, viz. menstruation.
At the period of puberty, the development of the genital parts in both
sexes, gives much activity to a part of the genito-urinary surface;
then menstruation begins upon that of the womb; then the sensibility
of the urethra is raised in order to feel acutely the passage of the
semen. Observe that this increase of energy is not attended with a
weakness of the other parts, as happens in many cases; on the contrary,
all the systems, all the apparatus seem to borrow, from the force which
the genital parts acquire, an increase of action.
II. _State of the Mucous System in the subsequent Ages._
In the years which succeed youth, the mucous system continues to grow,
thicken and become firmer. Its vital energy seems still to predominate
for some time, in the superior surfaces, as in the pituitary, the
membrane of the bronchia, &c.; thus the affections of these parts are
more frequent until the thirtieth year. But as we advance in age, the
abdominal mucous surfaces appear to predominate over the others, as in
general all the organs of this region do.
Besides, a thousand causes in the course of life, make the state of
the mucous system vary. We do not find it in two subjects, with the
same shade of colour, with the same density, with the same external
appearance. By taking any surface upon many subjects, that of the
stomach, for example, we easily see these differences, with which we
must be struck if we have opened dead bodies but ever so little.
The redness of the mucous texture is very bright until the thirtieth
year; after that, it begins to alter. This texture becomes more and
more pale in old age; the blood enters it but in small quantity; it
acquires more consistence and density. The fingers carried over it
no longer perceive that softness, that velvet so remarkable in the
first age. Its forces, which grow languid, render difficult, in the
excretories, the exit of the fluids which pass through these tubes to
be thrown out. Yet the mucous glands still secrete their fluids in very
great abundance. Often even these fluids increase in proportion which
constitutes the catarrhal affections, so common in old age. But these
affections then have the same character as the functions of the whole
system; secretion takes place slowly; the disease is always chronic;
most often it terminates only with life.
The mucous absorption is, at this age, slow and difficult, like all the
others; the various contagions are taken much less easily, either by
the respiratory surfaces, or by the contact of contagious miasmata upon
the neighbouring surfaces of the skin. The chyle slowly absorbed, makes
the digestive periods longer.
SEROUS SYSTEM.
This system, the name of which I borrow, like that of the preceding,
from the fluid that constantly lubricates one of its surfaces, is
always like it arranged in the form of membranes, and never in
fasciculi like the muscular system, or in round bodies like the
glandular. It is formed by the peritoneum, the pleura, the pericardium,
the arachnoides, the tunica vaginalis, &c. The term serous membrane
will then be very often used to designate it. No one, I believe, before
the publication of my Treatise on the Membranes, had considered in a
general manner these organs, which perform a less important part in
the functions than the mucous, but which in diseases are almost as
frequently affected. Pinel, who has perceived the analogy of their
inflammations, has taken this system as a character of one of the
classes of his phlegmasiæ.
ARTICLE FIRST.
OF THE EXTENT, FORMS, AND FLUIDS OF THE SEROUS SYSTEM.