The Vagina

Categories: 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.

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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).