644
UTERUS AND ITS APPENDAGES.
nerally softer and less tenacious in proportion
as they are younger.
c. The uterus during menstrual life. The
average duration of menstrual life is thirty
years. It occupies usually the interval be-
tween the ages of fifteen and forty-five. The
uterus in healthy women, throughout this en-
tire epoch, is maintained in a state of perfect
aptitude for the reproductive office, being, so
to speak, under the control of the ovaries,
with which it manifests so direct a sympathy,
that every periodic change in the condition of
the latter is, so far as the present state of our
knowledge justifies the assertion, represented
by a corresponding preparatory change in the
former. But the menstrual phenomena being
reserved for subsequent notice, it is only ne-
cessary to remark here that the uterus under-
goes usually a slight alteration in size about
the time of each eatamenial flow, when its
tissues are opened up, and become more spongy
from the larger afflux of blood to them.
The lining membrane appears to suffer a va-
riable amount of disintegration. In the uterus
of women who have died during menstruation,
the interior may present a slightly roughened
appearance in certain places, or this may ex-
tend over the greater portion of the cavity.
In women who menstruate painfully, it not
infrequently happens that the entire uterine
lining, to a greater or less depth, is exfoliated
and discharged ; the process of expulsion
being accompanied by much suffering and a
greater escape of blood than occurs in ordi-
nary menstruation. These dysmenorrhceal
membranes (fig. 443.) present all the charac-
Fig. 443.
Portion of the lining membrane of the uterus cast off
during painful menstruation. (Ad Nat.}*
teristics of a true decidual structure, having
upon their inner side, or that which had cor-
responded with the uterine cavity, the fine
cribriform surface occasioned by the orifices of
numerous utricular glands, and upon the re-
verse side the usual rough flocculent appear-
* For this illustration
Oldham.
I am indebted to Dr.
ance characteristic of the outer surface of
membranes ordinarily discharged, along with
the ovum, in abortion.
In other respects, the uterus, throughout
menstrual life, exhibits little or no alteration
in form or bulk, but continues to present those
characteristics of constant aptitude for its
greatest and most important office, which have
been explained in the description already given
of the adult organ ; and these characteristics,
if no pregnancy intervenes, it preserves until
the period arrives at which menstruation, to-
gether with the capacity for procreation, finally
ceases.
d. The uterus during gestation. The fully
developed uterus. The gravid uterus is only
another term for the fully developed uterus ;
for, although the latter designation is com-
monly applied to the unimpregnated organ,
when it has reached its ordinary size in the
adult, the uterus does not attain the greatest
amount of development of which it is nor-
mally susceptible until the term of gestation
is complete.
The case of the uterus is perhaps in certain
respects sui generis ; for it is the case of an
organ which, having reached a certain period
of growth, remains in a nearly passive con-
dition, so far as mere growth is concerned,
until a further amount of development is
evoked by a new stimulus. There are, in-
deed, two notable periods in the history of the
development of the uterus, at which the in-
fluence of such an additional stimulus is per-
ceptible.
For, first, as already shown, the uterus,
like the mamma, remains without any material
change from birth to puberty. The establish-
ment of the latter condition is characterised
by a correspondingly rapid evolution of both
these organs. But the pubertal age may not
arrive ; the individual may retain, in respect
of reproductive capacity, the pre- pubertal con-
dition ; and the uterus, in these cases, does
not proceed beyond its first stage of develop-
ment.*
Again, the second stage, having been reached
at puberty, may be continued through men-
strual life, until, with the cessation of pro-
creative power, the period of natural decline
in the organ commences, and this is the con-
dition which the part retains during the pe-
riods or intervals when it is not employed in
the process of reproduction, as well as through-
out life in those cases in which it is never so
employed. This degree of growth of the ute-
rus is evoked by the full development of the
ovary and the commencing discharge of ova,
and is coexistent with the establishment of
menstruation and the other conditions of pu-
berty.
But a third stage of development of the
uterus is produced normally by the stimulus
of impregnation, and partly by the growth of
the ovum, and abnormally by the formation of
* Compare >"# 405., representing the pre- pubertal
uterus in a -woman agerl nineteen, with fig. 442., of
the uterus of a child at three years.
UTERUS (DEVELOPMENT).
any substance within the uterus, such as a
polypus, which may cause distension of its
walls ; or by the accumulation of fluid in its
cavity, such as the menstrual fluid collected
in cases of atresia or impsrforation of the
vagina.
The development of the uterus which is
occasioned by the stimulus of pregnancy, takes
place whether the impregnated ovum arrives
within the uterine cavity or not ; although
this does not occur in equal degrees in the
two cases. In the case of extra-uterine preg-
nancy, a very considerable thickening of the
uterine substance usually takes place, together
with a general enlargement of the entire organ,
fully equal to that which is observed in the third
month, and, in some cases, when gestation is
not interrupted, even in the fourth month of
ordinary pregnancy.
In cases where gestation follows an ordi-
nary course, the development of the uterus is
such, that the weight, at the end of the period,
is found to be increased about twenty-four-
fold, and its length about five-fold.
This development, as it affects the size,
weight, form, and position of the entire organ,
as well as the physical condition of its special
parts, will now be considered.
There is no example in man, and few in the
animal kingdom generally, of a development
of any organ or structure comparable in rapi-
dity with that which takes place in the uterus
during gestation, although the periodical
growth of the deer's horn, and the formaiion
of the placenta, may be quoted as in some
respects analogous cases.
Size. The rate of increase of the uterus,
during pregnancy, is subject to great varia-
tions. But, with due allowance for these,
which are dependent chiefly upon the size of
the foetus and placenta, the quantity of liquor
amnii, or the number of ova fertilised, an
approximate estimate may be formed of the
average alterations in size and bulk which the
organ exhibits at different periods of normal
gestation.
These may be expressed in calendar months
as follows :
RATE OF INCREASE IS SIZE OF THE GRAVID
UTERUS ACCORDING TO MONTHS.
Length.
Breadth.
End of 3 months
4 5 inches
4 inches.
4
5 6
5
5
6 7
5i
G
7
89
10
i
8
11
8 .,
9
12
9
The antero-posterior has usually an average
of one inch less than the lateral diameter.
Weight. The weight of the gravid uterus,
when fully developed, is most correctly ascer-
tained in cases where death has taken place
during, or soon after, labour at term. In
twelve examples, estimated by Meckel, the
645
minimum weight was 2lbs., and the weight,
relatively to the unimpregnated organ, was
as 2-4 to' 1.*
Form. The form of the uterus undergoes
many changes in the course of gestation.
During the first three months, although there
is a considerable increase of size, the primitive
figure is retained with only slight alterations.
After the third month, the body rapidly en-
larging, while the cervix remains nearly un-
altered, the figure of the former approaches
that of a sphere. For the perpendicular and
transverse diameters of the body then become
nearly equal, and the only deviation from the
spherical form is occasioned, first, by the
cervix, which increases the vertical dia-
meter of the entire organ by one inch ; and
secondly, by the more tardy expansion of the
body in the antero-posterior diameter, pro-
ducing the form of a flattened sphere. After
this, the perpendicular increasing more rapidly
than the transverse diameter, and the upper
segments widening faster than the lower ones,
the uterus gradually acquires the ovoid figure
which characterises it at the end of pregnancy.
Alterations, nearly corresponding with these,
take place in the cavity of the uterine body.
The walls of this flattened triangular chamber
begin to separate from each other ; and by
their gradual expansion,, the angles and supe-
rior and lateral lines, by which the cavity was
at first bounded, are unfolded, so that the tri-
angular is gradually exchanged for the pyri-
form shape, and this again for the figure of a
flattened sphere as in the fourth and fifth
months of gestation ; after which period the
figure of the cavity corresponds very accu-
rately with the general external form of the
organ.
During these alterations, the fundus be-
comes strongly arched; while the sides un-
dergo a slighter relative expansion, so that
they exhibit only a gentle swelling ; but the
anterior and posterior walls become curved
and prominent sometimes the former, and
sometimes the latter, according to Dr. W.
Hunter, showing the greater amount of con-
vexity.f
It has often been asked whether, during
these changes, the walls of the uterus increase
in thickness, or the contrary. In other words,
whether the dilatation of the uterine cavity is
to be regarded as a mere passive distension,
with thinning of the walls; or whether the
process of enlargement consists of an active
excentric hypertrophy.
In order to determine this point, Meckel
examined the average thickness of the uterine
walls at different periods of gestation. From
observations which he had made in sixteen
uteri, at all periods of gestation, he concluded
that the walls increase a little in thickness in
the beginning, but that this increase is not
very considerable, and that towards the end
of pregnancy they become gradually much
* The estimates of Heschl, given at page 658.,
differ somewhat from these.
f W. Hunter. An anatomical description of the
human gravid uterus, page 5.
T T 3
646
UTERUS AND ITS APPENDAGES.
thinner. He found the thickness of the ute-
rine walls, three weeks after conception, 6'";
Fig. 444.
Human gravid uterus at eight months. The vessels
have been injected, and the peritoneum removed from
the sides and fore-part of the uterus. {After Wm.
Hunter.)
a, commencement of the cervix; bb, portion of
the body corresponding with the brim of the pelvis ;
cc, Fallopian tube concealing the ovary; dd, round
ligament ; e, hypogastric artery, and /, vein ; g,
spermatic artery, and h, vein.
at the commencement of the third month, 5'" ;
at the commencement of the fourth month,
4 /// . At the end of the fourth month, in two
cases, 4 /x/ ; in a third, %"' at the upper, and
4 X// at the lower part ; in a fourth, 5'". At
five months, in one case, 3'"; in another, 2"'
superiorly, and 4"' inferiorly. At six and
seven months, rather less than 3'" ; at eight
months, in one case, 2 /// , and 2^'" ; and in
another, 3"' above, and more than 4'" below.
At nine months, they appear to be still rather
thinner.
In several uteri, which I have examined at
all stages of gestation, I have found the thick-
ness of the uterine walls exceedingly variable
in different instances, even at corresponding
periods of pregnancy, and particularly variable
also in different parts of the same uterus.*
According to my measurements, the extremes
of thickness range from 2'" to 9"'.
* This circumstance is remarkably exemplified
in prep. No. 3605, in the Museum of the Koyal
College of Surgeons, London.
During these changes, which take place in
; the uterine body in the course of pregnancy,
similar, but much slighter, alterations occur in
the cervix. For the latter, being only the ex-
cretory channel of the uterus, undergoes no
further modification than is necessary to pre-
pare it for transmitting the foetus when fully
developed. Accordingly, in the early months
of gestation, while the body is rapidly en-
larging, the cervix undergoes but little change.
Its tissues, however, become slightly expanded,
so that the whole part is thicker, softer, and
more elastic than in the virgin state. The
margins of the os externum are consequently
rendered more cushiony, and the orifice itself
is enlarged. The canal of the cervix is also
widened, and the palmse plicatae become un-
folded, and project in the form of frill-like
expansions (jtfg. 446.) ; while an unusual ac-
tivity, occurring in the crypts and follicles,
by which these parts are covered, a tough
gelatinous secretion is poured out, which
Fig. 445.
Os and cervix uteri in the eighth month of pregnancy.
The os is surrounded by a broad disc of enlarged
cervical follicles filled with a gelatinous secretion.
The os is represented as seen from the vagina, va,
vaginal walls divided ; u, walls of uterus. Half the
natural size. {Ad Nat.)
collecting here in the form of a plug, assists
in shutting out the uterine cavity and its
contents from contact of external air and
other influences.
The increase in size of the os and cervix,
which is gradually progressive through the
whole of gestation, will be sufficiently ex-
pressed by comparing the dimensions of these
parts in their two extreme states. The virgin
cervix measures usually at the base 7 & f/f in
its shorter, and 11 12" 7 in its transverse dia-
meter, and has an aperture of 3 4'" wide.
It projects into the vagina to the extent of
4 /// (fig. 425). At the end of pregnancy,
the whole vaginal portion of the cervix would
fill a circle of 1^" diameter ; the orifice
measures transversely 10 II" 7 ; and that
part which formerly projected into the fornix
of the vagina, is now reduced nearly to the
level of the vaginal walls.
During these changes, it is often observed,
especially in a first pregnancy, that, as gesta-
tion advances, the projection of the cervix
UTERUS (DEVELOPMENT).
uteri into the upper part of the vagina be-
comes gradually less and less distinctly ascer-
tainable by the finger. The latter change is
commonly termed the "shortening of the cer-
vix;" but the conditions upon which it de-
pends, have not been very accurately examined,
and they are certainly not at all clearly or
adequately represented by the figures by
which the description of this process is usu-
ally accompanied. As much importance is
usually attached, in works on forensic and
obstetric medicine, to the changes in question,
it will be necessary here to examine a little
more closely the process by which this appa-
rent shortening of the cervix is produced.
It is commonly said that no material altera-
tion, in the length of the cervix uteri, occurs
before the fifth month of gestation ; that, at
the sixth or seventh month, the uterine neck
has begun to shorten ; at the eighth month,
it is nearly, and at the end of the ninth month,
it is quite, obliterated.
But while it is true that a lessening of the
projection of the cervix into the vagina com-
monly takes place in pregnancy (fig. 446.),
I can hardly coincide in the explanation which
is usually offered of this circumstance, namely,
that it is due to a gradual drawing up, as it
were, of the cervix, by which its walls become
added to those of the body of the uterus, for
the purpose of increasing the capacity of the
uterine cavity ; and that in this way the ute-
rine neck is gradually shortened, until it finally
disappears.*
The accompanying fig. 446. exhibits the
condition of the cervix in a woman aged
thirty-seven, who, having previously borne
children, died of phthisis in the eighth month
of pregnancy. Here it will be perceived, that,
without any actual diminution of the length
of the cervix, which measured rather more
than one inch, still there is no projection of it
into the vagina ; but that it forms a flat roof
to that canal in the mode which is usually
described and explained as indicating the en-
tire absorption of the uterine neck. The true
explanation of this, as it appears to me, is,
that the apparent shortening of the neck is
caused not, at first, by any diminution of its
actual length, but by an increase of its breadth,
or its extension in the lateral direction, where-
by the projection of the lips into the vagina is
reduced to the smallest possible amount. The
rest of the process, upon which the shorten-
ing of the cervix depends, may be explained
* See description of the figures in Gooch : "An
account of some of the most important diseases
peculiar to woman," p. 212 ; and Beck's Elements
of Medical Jurisprudence, oth edit. p. 128.
Regarding this explanation, which had been given
by many preceding authors (see Mauriceau, torn. i.
p. 97.; Smellie, vol. L p. 183. et seq.), but which
Gooch was, I believe, the first to illustrate by dia-
grams, it appears to me that much imagination has
been exercised. The illustrations usually given are
evidently diagrams supplied for the purpose of
aiding the description of the process, as it has
been supposed to occur, from examination of the
part by the finger during life, but they give a very
imperfect notion of the actual state of the cervix
in pregnancy, as ascertained by dissection.
647
by the variable condition of the internal os
uteri, or upper orifice of the cervix. If this
remains unyielding until the time of labour,
Fig. 446.
Vertical section of the os and cervix uteri represented
in the last figure.
v, walls of vagina ; c, of cervix, and , of uterine
body. The cervical canal is nearly filled by the
expanded palmae plicatse. Half the natural" size.
(Ad Nat.)
then the finger, on being placed within .the
cervix, traverses the whole length of the canal
before it reaches any part of the child ; and
the general form and substance of the cervix
being retained, the neck is said to be unob-
literated. Such is usually the state of parts
after repeated pregnancies. But if the in-
ternal or upper os yields readily, as it usually
does in the more advanced stage of a first
pregnancy, then the head of the child gradu-
ally settles down upon the lower orifice, press-
ing aside the soft and yielding wall of the
cervix, which thus forms for it a shallow, cup-
like, or funnel-shaped recess, that may be so
far said to be added to the uterine cavity ; and
the finger, on passing within the os readily,
touches the child, without having to traverse
any length of cervix.
When, therefore, the term, shortening of
the uterine neck, is employed, it should be
understood to imply that change which takes
place from the hypertrophy and lateral exten-
sion of the vaginal portion of the cervix, com-
bined sometimes with a separation of the cer-
vical walls from each other, occasioned by the
descent of the head of the child ; the degree
of this descent being regulated by the amount
of yielding of the internal os uteri. But it
does not signify any alteration in the anato-
mical condition of the cervix and body of the
uterus, which in every case retain their dis-
tinctive characteristics to the end of preg-
nancy : while the dilatation of the cervical
canai is only an occasional occurrence, limited
to the last stage of pregnancy, and having
nothing to do with that apparent shortening
which begins after the fifth month.
Position actual and relative. The enlarge-
ment which the uterus undergoes during ges-
tation, occasions of necessity very considerable
alterations in its actual and relative position.
On the occurrence of pregnancy, the organ, at
first concealed within the pelvis, sinks, by its
increased weight, lower than usual within that
T T 4
648
UTERUS AND ITS APPENDAGES.
cavity; and, pressing upon the bladder and
rectum, occasions sometimes an irritable con-
dition of these parts. But usually at the end
of the third month, the fundus may be felt
emerging from the pelvic cavity ; and in the
course of the fourth month, it is always easily
distinguishable in the lower part of the hypo-
gastric region, having then risen to the height
of about three fingers-breadth above the pelvic
brim. In the fifth month, the hypogastric
region is completely filled ; the abdomen then
acquiring a considerable rotundity in this situ-
ation. By the termination of the sixth month,
the umbilical region also is filled, and the
fundus uteri may be felt on a level with, or a
little above, the navel. In the course of the
remaining three months, the uterus rises gra-
dually, until its fundus reaches the level of the
ensifonn cartilage. And this is very nearly
the limit of its ascent, though it occasionally,
and chiefly in first pregnancies, rises slightly
above that point. In women who have a
roomy pelvis, and in those cases where the
natural form of the uterus is not altered by
over-distension nor mal- position of the foetus,
there usually takes place, a few days or shortly
before labour, a certain descent of the uterus,
which has the effect of partially emptying the
epigastric region, and relieving it from the
pressure which it had sustained, especially
during the last month.
The direction which the uterus takes in
rising from the pelvis into the abdominal ca-
vity, is determined by various circumstances ;
and it is interesting to observe in what way
the addition of so large a body as the fully
developed uterus to the already occupied ab-
domen, is provided for, without any of the
viscera suffering injurious pressure, and with-
out that impediment to the circulating and
respiratory systems, which, in the absence of
such a provision, must inevitably take place.
The oblique direction of the uterus, up-
wards and forwards, is determined, firstly, by
the corresponding obliquity of the pelvis, the
plane of whose brim forms with the horizon
an angle of 60. But as the fundus gradually,
after three months, emerges from the pelvic
cavity, the oblique direction of the uterus is
maintained by the symphysis pubis in front,
and the sacral promontory behind. Between
these, the superior portion of the uterus con-
tinues to ascend, supported next by the abdo-
minal walls anteriorly, and the spine poste-
riorly. The intestines, being bound down by
the mesentery, cannot be displaced, and will
Fig. 447.
Position of the uterus at the end of pregnancy. (After Maygrier.)
UTERUS (DEVELOPMENT).
649
therefore occupy a position midway between
the spinal column and the posterior uterine
wall. The pressure of the sacral promontory,
and of the lumbar vertebrae, will still give to
the uterus a forward tendency, which, on the
other hand, will be prevented from becoming
excessive by the elasticity of the front walls
of the abdomen. If these have not been pre-
viously much distended, the fundus glides
upwards, and ultimately fills the epigastric
hollow ; but if the abdominal walls have been
much relaxed, as by frequent child-bearing, or
if the pelvis is much deformed, the fundus
uteri is usually turned directly forwards, or
even downwards.
At the end of pregnancy, the whole of the
fore part of the abdomen is occupied by the
uterus ; on either side lie the ascending and
descending colon ; the transverse arch, to-
gether with the omentum and stomach, fill the
space between the fundus of the uterus and
the diaphragm, while the rest of the abdomi-
nal viscera lie laterally and posterity to its
hinder wall.
Thus it results, that in pregnancy, and espe-
cially in its last stages, no injurious pressure
is exercised, either upon the great vessels, the
aorta and vena cava, or upon the intestines,
liver, or stomach, whilst the descent of the
diaphragm, and, consequently, the act of
respiration, is not materially impeded, and
space is left for the bladder and rectum to
perform their appropriate acts.
The situation and direction of the pregnant
cervix, are necessarily affected by the increase
of the principal organ, as well as by its con-
tents. So long as the weight of the uterus
causes it to descend lower into the pelvic
cavity, as in the second and third months, the
cervix is more readily reached, lying in the
lower part of the hollow of the sacrum ; but