THE VULVA.
Forming a sort of flattened ring, with a long longitudinal diameter, directed from above downward, and from in front backward, the vulva is composed of the labia majora, the labia minors, the clitoris, the urinary meatus, and the vestibule. Besides these we find the hymen and the myrtiform caruncles, and the navicular fossa with the vulvar orifice.
I. Labia Majora. (See Fig. 52.) These are two folds of skin, which extend from the anterior and median part of the mons veneris, to the anterior portion of the perineum. In the centre they are separated by the vulvar cleft, but they unite above and below to form the vulvar commissures.
The anterior commissure is round, and is above the clitoris, from which it is separated by a space of about I inch. The posterior commissure is more acute. This latter unites with the corresponding part of the peri neum and forms a prominent fold, called the fourchette. This fold is separated from the entrance of the vagina by a depression that forms the fossa navicularis.
The external surface of the labia majora is convex and covered with hair. It is separated from the thigh by the genito-crural groove or fold.
The internal or mucous surface is almost completely without hair, is of a rosy color, and is applied to the corresponding surface of the opposite labium.
The anterior edge is free, rounded, and slightly convex.
The posterior edge is attached to the ischio•pubic ramus, and is con tinuous with the soft tissues of the surrounding parts.
In virgins and stout young women, the labia majora are firm, thick, even, and fit exactly one against the other; in multipara3, and aged or thin women they are flabby and loose. The vulva, which is closed in the former, is slightly open in the latter. It is even the same in children on account of the incomplete development of the labia.
Structure.—The skin of the labia majors is noticeable for the develop ment of its hair follicles and sebaceous glands. It also contains sudoripa rous glands, remarkable for their size and number.
Below is found what Sappey called the elastic apparatus of the mons veneris and the labia majora. It is composed of an anterior portion, two lateral lamina and a posterior part.
The anterior portion is composed of a series of lamelke, which pass from the hypogastric and the superior edge of the pubes to the mons and labia majora. They divide into several groups: a median, which forms the superior ligament of the clitoris, and which passes to the right and left of the vaginal bulb and the constrictor vulviv, to finally blend in the peri neum with the thin elastic lamina that proceeds from it. Two lateral, which descend in front of the inguinal ring, and blend with the median and lateral lamellie.
On the external and anterior edges of the labia majora are smooth fibres which form the dartos of woman. They only differ from the dartos in man by the atrophy of the fascia, and the fibres which compose it. In woman the two fascia do not unite, but remain separate, so that the dartos is really double.
Broca described a special pyriform sac situated in the thickness of the labia majora, and the large end of which pointed downward, and back ward, while the small end pointed upward, forward and outward, towards the orifice of the inguinal canal. He called it the dartoic sac of woman. Sappey has shown that this sac is not, like the dartos, composed of mus cular fibres; that it is not a true dartos, but that it is composed of elastic fibres which cross each other. He described it under the name of the elastic apparatus of the labia majora.
The cellular tissue forms an adipose layer between the dartos and the elastic apparatus. It accumulates especially in this latter, and thus helps maintain the shape of the labia majora.
The arteries come from the inferior perineal, from the external pudic, and from the epigastrics.
The veins unite with the veins of the bulb.
The lymphatics pass only to the inguinal glands.