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upper part of the cervix is covered by peritoneum, and below this level the membrane
passes on to the posterior wall of the vagina, which thus separates the lower part of
the back of the cervix from the peritoneum. From the sides of the uterus the
peritoneum is prolonged outwards in the form of duplicatures named the broad
ligaments.

Cavity of the uterus. The walls of the uterus are of great thickness, and the
cavity is thus proportionately much reduced in size. The part within the body is




Fig. 274. DIAGRAMMATIC VIEW OF THE UTERUS AND ITS APPENDAGES, AS SEEN FKOM BEHIND. (A. T.) |.

The uterus and upper part of the vagina have been laid open by removing the posterior wall ; on the
left side the Fallopian tube, round ligament, and ovarian ligament have been cut short, and the broad
ligament removed ; u, the fundus of the uterus ; c, the cervix opposite the os internum ; the triangular
shape of the uterine cavity is shown, and the dilatation of the cervical cavity with the rugae termed
arbor vitse ; v, upper part of the vagina ; od, Fallopian tube or oviduct ; I, round ligament ; lo,
ligament of the ovary ; o, ovary (here represented with its long axis horizontal although in the natural
position within the body it is oblique or nearly vertical) ; i, wide outer part of the right Fallopian tube ;
/ i, its fimbriated extremity ; po, parovarium ; h, one of the hydatids frequently found connected with
the broad ligament.

triangular (fig. 274), and flattened from before backwards, so that its anterior and
posterior walls touch each other (fig. 273). The base of the triangle is directed
upwards, and is convex towards the interior of the uterus. The cavity, narrowing
gradually, is prolonged into its two superior angles, at each of which it leads by a
minute foramen into the narrow canal of the Fallopian tube. At the junction of
the body and the neck, the cavity is slightly constricted, and thus forms what is
sometimes named the internal orifice (ps uteri internum, isthmus vel ostium uteri) ;
this opening is often smaller than the os externum, and is of a circular form. That
portion of the cavity which is within the neck is tubular and slightly flattened
before and behind ; it is somewhat dilated in the middle, and opens inferiorly into
the vagina by the os uteri externum. Its inner surface is marked by two longitu-
dinal ridges or columns, which run, one on the anterior, the other on the posterior
wall, and from both of which rugee are directed obliquely upwards on each side, so
as to present an appearance which has been named arbor vihc, uterina, or palmcc,
plicatcc, (fig. 274) : this structure is most strongly marked anteriorly.

Position of the uterus. The question as to the normal position of the
uterus is one that has given rise to much controversy, and regarding which very



THE UTERUS.



63



contradictory statements have been made. The uterus does not occupy any definite
fixed position, but possesses a considerable range of mobility, the chief factors that
influence its position being the intra-abdominal pressure, and the condition of the
bladder and rectum. In the nullipara, with the bladder empty, the whole uterus is
inclined forwards (anteverted), and the body is also bent upon the cervix (anteflexed),
the body of the uterus lying upon the bladder. As the bladder becomes filled the
body and fundus are pushed upwards and backwards, until, if the bladder be fully
distended and the rectum empty, the upper part of the uterus may come to lie near
the sacrum, and the long axis of the organ be directed from above downwards and
forwards nearly parallel with that of the vagina. As a rule there are no intestines
in the pouch between the uterus and the bladder, these two organs lying in close




Ureter.
Rectum.

Suspensory liyit-
ment of ovary.

Utero-sacral
ligament.

Fallopian tube.
Ovary.

Ligament of ovary
Broad ligament.



Urachiis.

Obliterated Itypo-
gastric artery.



Fig. 275. VIEW OF THE FEMALE PKLVJC VISCKKA FROM AUOVE. (v. Bardeleben and Haeckel.)

U, uterus ; B, bladder.

contact. Occasionally however, especially in women who have borne children, the
upper part of the uterus points somewhat backwards, and the utero-vesical pouch is
occupied by some portion of the intestine. The uterus generally deviates to one or
other side, this lateral displacement usually affecting the body more than the cervix.
Ligaments of the uterus. The reflection of the peritoneum from the uterus
to the bladder is called the utero-rcsical fold or sometimes the anterior ligament of
the uterus. Posteriorly, as we have already seen, the peritoneum passes from the
uterus on to the upper part of the vagina before being reflected backwards to the
rectum, thus forming a recto-vaginal ligament. The peritoneal recess situated in
front of the rectum, and behind the cervix of the uterus and the upper part of the
vagina is usually termed the pouch of Doiif/Jas. This pouch is bounded on each side
by a semilunar fold of the peritoneum, which joins the upper part of the cervix
uteri in front and extends backwards en the side of the rectum towards the sacrum.
This fold contains a variable amount of fibrous tissue and some non-striped
muscular fibres forming the nfcrc-sacral ligament.



24 FEMALE REPRODUCTIVE ORGANS.

The broad ligaments (fig. 274) are formed on each side by a fold or double
layer of the peritoneum, which is directed laterally from the anterior and
posterior surfaces of the uterus, to be connected with the sides of the pelvic cavity.
Between the two layers of the serous membrane are placed the Fallopian tube, the
round ligament of the uterus, the ovary and its ligament, the parovarium, and
numerous blood-vessels, lymphatics, and nerves with fibres spreading from the
superficial muscular layer of the uterus. The Fallopian tube is situated at the
upper border of a special fold of the broad ligament sometimes termed the meso-
salpinx. This fold is attached to the main part of the broad ligament close to the
ovary and its ligament. It is narrow internally, but broadens as it passes outwards.
The parovarium is enclosed within its two layers between the ovary and the outer
part of the Fallopian tube. This fold is thin, its serous layers being separated by only
a small quantity of areolar and muscular tissue. The ovary and its ligament are
situated in a special extension from the posterior part of the broad ligament. The liga-
ment of the ovary is merely a dense fibro-areolar cord, containing some uterine mus-
cular fibres, and measuring from an inch to an inch-and-a-half in length, which
extends from the lower end of the ovary to the upper angle of the uterus, which
it joins immediately below and behind the point of attachment of the Fallopian tube.

The round ligaments are two flat, cord-like bundles of fibres, about four or
five inches in length, attached to the upper angles of the uterus, one on either side,
immediately in front of the Fallopian tube. As each ligament proceeds upwards,
outwards, and forwards towards the internal abdominal ring it raises the anterior
layer of the broad ligament into a more or less prominent fold. After having
passed, like the spermatic cord in the male, through the inguinal canal, it reaches
the fore part of the pubic symphysis, where its fibres expand and become united with
the substance of the mons Veneris. Besides areolar tissue and vessels, the round
ligaments contain, chiefly in their inner third, plain muscular fibres, which are
prolonged into them from the outer muscular layer of the uterine wall. Each
ligament also receives a covering from the peritoneum, which, in the young subject,
projects in the form of a tubular process for some distance into the inguinal
canal ; this, which resembles the processus vaginalis originally existing in the same
situation in the male, is named the canal of Nuck ; it is generally obliterated in the
adult, but is sometimes found even in advanced life.

STRUCTURE OP THE UTERUS.

The walls of the uterus consist of an outer serous covering, an inner mucous
membrane, and thick intermediate muscular substance. The serous covering or
peritoneal layer has been already referred to.

The thick middle part of the wall of the uterus is of firm consistence : being
mainly composed of plain muscular fibres of small size, 0'23 mm. in length, in the
nnimpregnated uterus, but greatly enlarged in the gravid state. These fibres
interlace closely with each other, but are disposed in bundles and layers, and are
intermixed with areolar tissue, a large number of blood-vessels and lymphatics, and
some nerves. The areolar tissue is more abundant near the outer surface. The
arrangement of the muscular fibres is best studied in the uterus at the full period
of gestation, in which the bundles become augmented in size. They may be
referred to three sets of which the two more external may be regarded as
corresponding with the muscular coat of other hollow viscera, whereas the internal
is an immensely hypertrophied muscular is mucosce, and will accordingly be described
with the mucous membrane.

Muscular coat. The external layer of the muscular coat forms a thin
superficial sheet immediately beneath the peritoneum, and incomplete strata situated
more deeply. A large share of these fibres, beginning as longitudinal bauds at the



THE UTERUS. 265

cervix, arch transversely and obliquely over the fundus and adjoining part of the
body of the organ, and pass on each side into the broad ligament. Of these some
converge at either side towards the commencement of the round ligaments, along
which they are in part prolonged to the groin ; others pass off to the Fallopian
tubes, and strong transverse bands from the anterior and posterior surfaces are
extended into the ovarian ligaments. Other fibres run back from the cervix uteri
beneath the utero-sacral folds of the peritoneum. The inner layer of the muscular
coat, -which is also thin, is composed of fibres which are found chiefly on the back of
the uterus, and stretch over the fundus and towards the sides, running somewhat
irregularly between the ramifications of the blood-vessels. The muscular coat proper
seldom exceeds 6 mm. in thickness altogether, but it is not easy to assign its limits
exactly, for there is little or no submucous areolar tissue forming a distinct coat as in
most of the hollow viscera. But the place of ramification of the blood-vessels before
they pass into the mucous membrane serves to determine the boundary between the
muscular layer of the mucous membrane and the muscular coat proper (J.Williams).

Mucous membrane. The mucous membrane of the uterus is characterized by
the enormous hypertrophy of the muscular layer proper to it the muscularis
mucosse ; indeed it is this which forms the greater part of the thickness of
the uterine wall. The presence of this mass of plain muscular tissue in it confers a
distinct character on the outer part of the membrane, so that in sections it is
distinctly differentiated from the inner part or corium.

Muscularis mucosse. This consists of bands of fibres which are disposed with
comparative regularity in its upper part, being arranged there in numerous
concentric rings round the openings of the two Fallopian tubes, the widest circles of
the two series meeting from opposite sides in the middle of the uterus. In the
lower part of the body, and in the cervix the internal fibres run more transversely.
They form the so-called sphincters of the os iuternum and os externum. At the
neck, however, there are also longitudinal fibres within the transverse.

Corium. As regards its inner part or corium the mucous membrane lining the
cavity of the body differs greatly from that of the cervix, a distinct line of
demarcation separating the two parts at the isthmus.

The mucous membrane of the body of the uterus is smooth, except during the
menstrual period, and in the unimpregnated state is entirely devoid of ridges ; it is
of a peculiar soft spongy consistence, and of a dull, reddish colour.

Under the microscope it appears composed in great measure of small, rounded,
spindle-shaped, or irregular cells imbedded in a homogeneous ground-substance
and with but few connective tissue fibres apparent (fig. 27(5). According to
Leopold there are, however, numerous fibres, and they form a spongework with
lymphatic spaces in the meshes. The inner surface is everywhere covered by
columnar ciliated epithelium, and is beset, but somewhat sparingly, by the orifices
of the uterine glands (fig. 277). These, which were discovered by Sharpey, are
simple tubes bounded by a basement membrane and lined with ciliated columnar
cells like those covering the inner surface. They pass usually obliquely and often
with an irregular or convoluted course into the deeper part of the mucous membrane,
and there terminate by blind, sometimes forked extremities, which are situated
amongst the bundles of the muscularis mucosse. Towards their extremities the
uterine glands are entirely filled by cells (fig. 277, &'), but in the greater part of their
extent they have a distinct lumen.

The mucous membrane of the cervix is much firmer and more fibrous than that of
the body. Between the ruga of the arbor vitce there are numerous saccular and
tubular glands. In the lower part of the cervix the mucous membrane is beset with
vascular papillse, and the epithelium is stratified, but in the upper half or more the



266



FEMALE REPRODUCTIVE ORGANS.



epithelium is columnar and ciliated like that of the body. The glands, which are
short, with a large lumen, are everywhere lined with columnar ciliated epithelium,
even where the epithelium of the surface is stratified. Besides the follicular glands
there are almost constantly to be seen the so-called ovula Nabothi, clear yellowish
vesicles of variable size, but visible to the naked eye, embedded in the membrane.
These probably arise from closed and distended follicles ; but their exact nature is
still doubtful.

During pregnancy the mucous glands of
the cervix secrete a considerable quantity
of tenacious mucus, which effectually closes
the passage downwards from the uterine
cavity.

The surface of the os uteri is covered,
like the vaginal portion, with stratified
epithelium, which conceals the vascular
papillse. It is destitute of glands.

The arrangement of the muscular fibres
both of the muscular coat proper and of the
muscularis mucosas is more regular and more
easily made out in the uterus of the lower





Fig. 276. SECTION OF THE UTERINE MUCOUS MEMBHANE PARALLEL TO THE SURFACE (Henle). 4.
1, 2, 3, glands (the epithelium has fallen out from 2) ; 4, a blood vessel.

Fig. 277. SECTION OF THE MUCOUS MEMBRANE OF THE HUMAN UTERUS FROM NEAR THE FUNDUS (adapted
by J. C. Ewart from a figure from J. Williams).

a, epithelium of inner suface ; 6, 5, uterine glands ; c, interglandular connective tissue ; d, part of
the muscularis mucosse with the ends of the glands, some of which, b', are entirely filled by epithelium
cells. This specimen was prepared from the uterus of a young woman who was accidentally killed three
or four days before the expected appearance of the menstrual flow, and the mucous membrane and
glands are therefore in the hypertrophied condition which precedes menstruation.

mammals (below Primates), which possess a bi-corned uterus consisting of two long tubular
portions, which unite below before opening into the vagina. A section across one of the
horns of such a uterus is represented in fig. 278, from which it will be seen that the fibres of
the muscularis mucosae (7..-?.) run almost entirely in a transverse or circular direction, and
are imperfectly separated by an areolar layer (.) containing the large bloodvessels of the
organ from the inner thin layer of circular fibres of the muscular tunic proper (e.m.). Outside
these are seen the stout bundles of the outer or longitudinal muscular layer (Z.w.), and most
externally is the peritoneal or serous coat (.?.).



THE UTERUS.



267



Periodic structural changes in the uterus. The changes which accompany
menstruation and gestation may be shortly indicated here.

At each successive recurrence of menstruation a complete removahof-the super-
ficial part of the mucous membrane takes place by a process of softening and
molecular disintegration which commences, along with, the menstrual discharge,
close to the cervix, or at the os internum, and advances progressively towards the
fundus during the remaining days of the flow of blood (J. Williams). Previous to
this change, there is a greatly increased general vascularity of the parts, and the
mucous membrane becomes very much thicker. The process of disintegration
reaches as far as the inner fibres of the muscularis mucosae ; and the hemorrhage
is the direct result of the destruction and open condition of the small vessels.

The process of restoration of the uterine membrane, which begins even before
the cessation of the menstrual flow, proceeds in the same order, from the lower end

Fig. 278. TRANSVERSE VERTICAL SECTION

OP THE WALL OP ONE OF THE CORNUA
UTERI OP THE RABBIT. (E. A. S.)

, serous layer; I. m., longitudinal fibres of
the muscular coat ; c. m., circular fibres of
the same ; , areolar tissue with large blood-
vessels ; m. m., muscularis mucosse ; m.,
mucosa, with coiled glands.

upwards to the fundus, and consists in
a very rapid proliferation of the cells
and nuclei which occupy the inter-
stices of the inner muscular fibres,
and among which are embedded the
deepest parts of the uterine glands.
The whole of the destroyed epithelial
structure both of the glands and of
the general surface is renewed from
the epithelium of these parts of
the glands. The epithelial regenera-
tion is very rapid, and the inner sur-
face is already covered again with
epithelium very shortly after the
menstrual flow has ceased, but the
original thickness of the mucous membrane is not at once attained, the growth in
thickness progressing gradually up to the time of the next menstruation, and
with it the growth in length and the intricacy of the uterine glands. The lining
membrane of the cervix does not participate in the changes referred to.

In gestation more extensive alterations ensue. The weight of the organ increases
from about one ounce to a pound-and-a-half or even three pounds. Its colour
becomes darker, its tissue less dense and its muscular bundles more evident. A
very great increase takes place in the muscular tissue, this increase being mainly the
result of the enlargement of the already existing elements, the cells becoming
enlarged to the extent of from seven to eleven times in length, and from two to five
times in breadth (Kolliker). A formation of new cells is also said to occur mainly
in the innermost layers (but whether by proliferation of pre-existing cells or other-
wise is not stated), and to continue until the sixtli month of pregnancy, when
it ceases. The round ligaments become enlarged, and their muscular structure more
marked ; the broad ligaments are encroached upon by the intrusion of the growing




268



FEMALE REPRODUCTIVE ORGANS.



uterus between their layers. The mucous membrane and the glands of the body of the
uterus at first undergo an enlargement very similar to that which precedes menstrua-
tion, and they subsequently become the seat of peculiar changes, more particularly
described under Development (Vol. I., Part 1), whilst the membrane of the cervix
loses its columns and rugae. The blood-vessels and lymphatics are greatly enlarged,
and it is observed that the arteries become exceedingly tortuous as they ramify upon
the organ. The nerves also undergo considerable increase in size.

After parturition, the uterus gradually but rapidly diminishes till it nearly regains
the size and structure of the uuimpregnated condition. During this change the
enlarged muscular fibres undergo fatty degeneration and are said to become subse-
quently absorbed, while a new set of fibre-cells is developed. After the first pregnancy,




Fig. 279. OUTLINES OF MOULDS OF THE UTERINE CAVITY IN DIFFERENT STATES (after F. Guyon).

NATURAL SIZE.

A, in a virgin of 17 years of age ; B, in a woman of 42 years who had not borne children ; C, in a
woman of 35 years who had borne children ; b, cavity of the body ; c, that of the cervix ; i, the
isthmus or os internum ; o, os externum ; t, passage of the upper angle into the Fallopian tube.

however, the organ never regains its original virginal character. In those who have
had children its weight usually remains from two to three ounces (102-117 grammes,
Vierordt) ; its cavity is larger (fig. 279, C) ; the os externum is wider and more
rounded, and its margins often puckered or fissured ; the arteries remain much
more tortuous, and its muscular fibres and layers more defined than in the virgin.

Peculiarities according to age. In the newly-born infant the neck of the uterus is
larger than the body, and also much firmer. There is no fundus, the upper end of the uterus
not forming a convex prominence between the attachments of the Fallopian tubes. The
cavity is narrow, there is no distinct internal os and it tapers above on both sides so as to present
an approach to the two-homed form prevalent in animals. The arbor vitse is very distinct
and reaches to the highest point of the cavity. At this period the uterus is usually from an
inch to an inch-and-a-quarter in length. It grows but slightly from birth until near puberty,
at which period it undergoes a rapid and marked increase in size. This growth is especially
marked in the body, which at the same time acquires a firmer consistence, while its mucous
membrane becomes smooth. The cavity remains comparatively narrow in all women who
have borne no children (fig. 279, B). while in those who have been pregnant it is widely
triangular (c). In old age the uterus atrophies : it becomes paler in colour and harder in
texture, and its external os frequently becomes diminished in size.

Varieties. The uterus is subject to numerous congenital defects or malformations
especially in connection with abnormal conditions of the other genital organs. Amongst



THE FALLOPIAN TUBES. 269

those involving: the uterus may be mentioned its more or less complete absence, the occurrence
of one or two horns at its upper part, and the presence of two distinct cavities. Such cases
ara obviously due to an imperfect development of one or both Mullerianjducts or their
incomplete fusion (see Development, Vol. I., Pt. 1). Occasionally the uterus retains its
infantile condition after puberty.

Vessels and nerves. The arteries of the uterus are four in number, viz., the
right and left ovarian (which correspond to the spermatic of the male) and the uterine.
Their origin, as well as the mode in which they reach the uterus and ovaries, has been
described in Vol. II., Pt. 2. They are remarkable for their frequent anastomoses,
and also for their singularly tortuous course. After passing a short distance into
the thickness of the uterine wall they divide into branches, which penetrate the
muscular tissue of the mucous membrane, supplying it with capillaries, and then
pass towards the inner portion of the membrane and open into a network of large
capillaries which pervades the tissue in that situation, and is especially developed
near the surface and around the glands. In the cervix, however, and especially in
the vaginal portion, the arteries, which in this situation possess walls of considerable
thickness, after entering the mucous membrane, divide into a number of small
branches which pass directly towards the surface and open into the capillary
network there present, from which loops pass into the papillae. The veins
correspond with the arteries ; they are very large, and form plexuses of sinus-like
vessels, with thin walls in immediate contact with the uterine tissue. The lymphatics
commence according to Leopold as cleft-like spaces in the mucous membrane, and
there are also well-marked lymphatic vessels extending as a plexus through the
whole thickness of the membrane (Hoggan). These open into plexuses of vessels in
the muscularis mucosaa and muscular coat proper ; and these again are in communica-
tion with valved vessels beneath and in the serous covering.

The nerves are derived from the inferior hypogastric plexuses, the spermatic
plexuses, and the third and fourth sacral nerves. They consist of both medullated
and non-medullated fibres, and in animals small ganglia have been observed in the
submucous tissue, connected with the non-medullated fibres.

THE FALLOPIAN TUBES.

The two Fallopian tubes may be considered as ducts of the ovaries (oviducts)



Online LibraryJones QuainQuain's Elements of anatomy (Volume 3:4) → online text (page 33 of 44)