THE EXTERNAL ORGAN8 1417 



are connected by oblique decussating fasciculi which pass from the one layer to the other. Above 

 the triangular ligament the fibres are nonstriated; in the region of the ligament they show stria- 

 tions. In addition to this, the vagina at its lower end is surrounded by a band of striped muscle 

 tissue, the Sphincter vaginae (p. 446). 



The fibrous coat is composed of dense white fibrous connective tissue, which connects the 

 vagina to the surrounding organs. It contains a large plexus of bloodvessels. 



The erectile tissue consists of a layer of loose connective tissue situated between the mucous 

 membrane and the muscular coat; embedded in it is a plexus of large veins, and numerous 

 bundles of unstriped muscular fibres derived from the circular muscular layer. The arrange- 

 ment of the veins is similar to that found in other erectile tissues. 



Bloodvessels, Nerves, and Lymphatics. The arteries of the vagina are branches of the 

 vesicovaginal artery, the vaginal branch of the uterine artery (p. 674), and branches of the 

 internal pudic and middle hemorrhoidal. The veins form an abundant plexus around the wall 

 of the vagina and pass to the internal iliac veins. The lymphatics (Fig. 1172) arise from two 

 communicating networks, one of which is below the mucous membrane, the other in the muscular 

 wall. There is a third network around the vaginal wall, from which the collectors arise. The 

 trunks from the upper third of the vagina pass to the external iliac nodes; those from the middle 

 third pass to the internal iliac nodes; those from the lower third terminate in the nodes at the 

 promontory of the sacrum or in the lateral sacral nodes. The nerves come from the third and 

 fourth sacral nerves and from the uterovaginal and vesical plexuses of the sympathetic. 



THE EXTERNAL ORGANS (PARTES GENITALES EXTERNAE MULIEBRES). 



The external reproductive organs in the female are the mons Veneris, the labia 

 majora and minora, the vestibule, the clitoris, the vaginal bulb, and the glands of 

 Bartholin. The term vulva (pudendum muliebre}, as generally applied, includes 

 all of these parts. In examining the structures entering into the formation of 

 the vulva we find the homologues of most of the structures which make up the 

 male genitals. 



Labia majora Scrotum. 



Clitoris Corpora cavernosa. 



Bulbus vestibuli Corpus spongiosum. 



Vestibular glands Bulbourethral glands 

 (of Bartholin). (of Cowper). 



The mons Veneris (commissura labiorum anterior} is the rounded eminence 

 in front of the pubic symphysis formed by a collection of fatty tissue beneath the 

 integument. It becomes covered with hair at the time of puberty. 



r Fhe labia majora (labia majora pudendi) (Figs. 1 173 and 1 174) are two prominent 

 longitudinal cutaneous folds, narrow behind but fuller and larger toward the mons 

 Veneris, and enclosing the pudendal slit (rima pudendi) or common urinogenital 

 opening. Each labium majus has two surfaces, an outer, which is covered by pig- 

 mentecf skin with numerous sebaceous glands and strong, crisp hairs, and an inner, 

 which is smooth and moist and is continuous with the genitourinary mucous 

 tract. In the subcutaneous areolofatty tissue of each labium majus the round 

 ligament of the uterus ends. The labia are joined with each other anteriorly 

 by the mons Veneris or anterior commissure. Posteriorly they appear to become 

 lost in the neighboring integument, although sometimes connected by a slight 

 transverse fold In front of the anus, the posterior commissure (commissura labiorum 

 posterior^ or posterior boundary of the vulvar orifice. The interval between 

 the posterior commissure and the anus, about an inch in length, constitutes the 

 obstetric perineum. 



Bloodvessels, Nerves, and Lymphatics. The arteries of the labia majora are derived from 

 the superficial external pudic arteries and from perineal branches of the internal pudic arteries. 

 Homoloo-ous with the scrotum, the nerve supply is derived from branches of the ilioinguinal, 

 internal" pudic, and perineal branches of the small sciatic. The lymphatics dram into the 

 superficial inguinal and internal iliac lymph nodes. 



