The Vagina

Category: Diseases of Women

This is a membranous canal and extends from the vulva to the
uterus (womb) and connects the external and internal organs of generation.
It is four to six inches in length, the anterior wall being from one to
two inches shorter than the posterior. It lies in the cavity of the pelvis
in front of the rectum, behind the bladder and follows first the line of
axis of the cavity of the pelvis, and afterwards the axis of the outlet.

The vagina consists of an internal mucous lining (membrane) continuous
above with the mucous membrane lining the womb and below with the covering
of the labia majora. The next covering (inward) is a muscular coat
consisting of two layers--an external longitudinal and an internal
circular. There is a layer of erectile tissue between the muscular coat
and mucous lining. The lower end of the vagina is surrounded by a band of
striped muscular fibers comprising the sphincter muscle of the vagina
(sphincter vagina).

The internal organs of generation, more commonly called the pelvic organs.
These comprise the womb, fallopian tubes and ovaries.

The womb is the organ of pregnancy, and receives the fruitful egg (ovum),
supports it during its development and expels it at the time of labor
(parturition). In form it is pear-shaped, weighs from 12 drams to 3 ounces
and is situated in the pelvic cavity, between the bladder and the rectum,
with its base upwards and its apex, smaller end downward. Its upper broad
extremity is called the fundus--base of the organ, and the lower,
constricted, narrowed portion is called the Cervix (neck or constricted
portion). The body of the womb gradually becomes narrower from the fundus
to the Cervix.

Its anterior surface is covered on its upper three-quarters by the
peritoneum, while the lower fourth is connected with the bladder. The
peritoneum covers the whole of the posterior surface. The womb is held up
(suspended) in the pelvis by ligaments; two anterior, womb and bladder
(utero-vesical), two posterior, womb-sacral (utero-sacral), two lateral
broad ligaments, and two round ligaments. The womb sacral (utero-sacral)
which holds the womb well up in the hollow of the sacrum and the round
ligaments which keep the womb well forward enter most actively into the
support of the womb. The round ligaments are strong muscular fibrous cords
and serve to hold the womb forward. When pregnancy exists they increase in
size with the womb, and keep the fundus forward in its excursion upwards
into the abdominal cavity, and after confinement, become smaller with the
womb, guiding the womb back again to its regular position. The broad
ligaments are little more than reflection of the peritoneum serving to
support the vessels that nourish, as they go to and from the womb.

The womb has three coats, enclosing a central cavity. This cavity of the
womb is small by comparison with the size of the organ and it communicates
with the Fallopian tubes by two minute openings at each side of the body,
and with the vagina below, through the mouth or opening of the womb.

The external coat of the womb is called servos, derived from the
peritoneum; the middle or muscular coat, which forms the chief substance
of the womb, consists of bundles of unstripped muscular fibers intermixed,
with loose connective tissue, blood vessels, lymphatics and nerves; the
internal or mucous coat is continuous through the fringed extremity of the
fallopian tubes, with the peritoneum, and through the mouth of the womb
(os uteri) with the mucous membrane of the vagina. This mucous membrane is
lined in the body of the womb by epithelium arrayed in columns (Columnar
Epithelium) which loses its ciliated (eye-lash) movement character during
pregnancy. In the lower half of the Cervix, the epithelium (this kind of
cell lines all canals having communication with the external air) is of
the stratified (arranged in layers) variety. The appendages of the womb
are the fallopian tubes, the ovaries and their ligaments and the round
ligaments. The fallopian tubes convey the ova (eggs) from the ovaries to
the cavity of the womb. They are two in number, one on each side, situated
in the free border of the broad ligaments and extend from each horn, an
excrescence of the womb that looks like a horn, of the womb outward to the
sides of the pelvis; each is about five inches in length, and has a small
canal beginning at the womb in a very small opening called the internal
mouth (ostium internum). This canal gradually widens to its ending, the
abdominal mouth (ostium abdominal) by which it communicates with the
peritoneal cavity, the timbrae. A series of fringe-like processes
surround this mouth or opening and this farther end is known as the
fimbriated extremity. The tube has three coats, serous or external or
peritoneal; the middle or muscular, continuous with that of the womb, and
an internal or mucous coat continuous also with the lining of the womb and
peritoneum (covered with ciliated Columnar Epithelium).

Next: The Ovaries
Previous: The Vestibule

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The Vagina