634 



A MANUAL OF ANATOMY 



In the female the urinary bladder is developed from the cephalic 

 part of the uro-genital sinus. The entire urethra of the female is 

 developed from the cephalic part of the uro-genital sinus, in succes- 

 sion to the urinary bladder. The caudal part of the uro-genital 

 sinus, becoming expanded, gives rise to the vestibule, into the 

 cephalic part of which the urethra opens, whilst the external orifice 

 of the vagina is caudal, or posterior, to it. 



The female external genital organs are developed around the uro- 

 genital opening. At the cephalic part of the primitive vestibule 

 a small tubercle, called the genital eminence, makes its appearance 

 in the median line. On the lower, or vestibular, surface of this 

 eminence a furrow, called the genital grove, is formed. The lips 

 of this groove, which are laterally disposed, are called the internal 

 genital folds. On either side of the genital eminence, external to 

 the corresponding internal genital fold, a prominent ridge makes 

 its appearance. These ridges are known as the external genital 



Male. 

 Raphi of Penis Glans Penis 



Female. 

 Glans Clitoridis Genital (Labial) Fold 



Anus 



Uro-genit;:' 

 Aperture 



Coccyx Coccyx 



Fig. 280. — Development of the External Genital Organs. 



folds. They are continuous with each other on the ventral aspect 

 of the genital eminence, and they extend dorsalwards, lying on 

 either side of the vestibule, and finally meeting behind in the 

 perineum. 



The genital eminence undergoes lengthening, and gives rise to the 

 clitoris. The terminal extremity of the eminence becomes enlarged, 

 and forms the glans clitoridis, whilst the remainder gives rise to the 

 corpora cavernosa clitoridis. 



The internal genital folds, which in the male fuse, enclosing the 

 spongy part of the urethra, and forming the corpus spongiosum 

 penis, remain separate in the female, and form the labia minora, 

 or nymphcB. The external genital folds, which in the male fuse and 

 form the scrotum, remain separate in the female, and give rise to 

 the labia major a. The ventral portions of the external genital 

 folds, which are continuous with each other on the ventral aspect 

 of the genital eminence, form the mons veneris. 



