THE BLADDER 371 



female they remain separated by the pudendal cleft and form the 

 labia majora. In the male, they fuse with one another, caudal 

 to the genital tubercle, and they thus roof in the perineal orifice 

 of the bladder, which then opens on the caudal surface of the 

 tubercle. The genital tubercle forms the penis and the 

 urethral orifice is situated at the base of the glans, which 

 becomes canaliculised at a slightly later period. The urethra 

 thus acquires its normal external orifice, and the opening at 

 the base of the glans disappears. 



Congenital Anomalies of the bladder and urethra are by 

 no means uncommon. In the condition of epispadias the 

 urethra opens on the dorsal aspect of the penis, which is more 

 or less malformed. A similar deformity may occur in the 

 female, the urethra opening on the dorsal aspect of the clitoris. 

 This condition is brought about by rupture of the genito- 

 urinary membrane on the cephalic instead of on the caudal 

 aspect of the genital tubercle. 



Hypospadias, which is the normal condition in the female, 

 may occur abnormally in the male. The anomaly varies 

 greatly in degree, (i) The orifice at the base of the glans 

 may persist the commonest and simplest form. (2) The 

 two halves of the scrotum may fail to fuse in the median 

 plane ; either partially or (3) completely, in which case the 

 perineal orifice of the urethra persists. 



Extroversion of the Bladder is merely an exaggeration of 

 the condition of epispadias. 



The NERVE-SUPPLY OF THE BLADDER is derived mainly 

 from the hypogastric sympathetic plexus (p. 188), and the 

 fibres have their lower centres in the eleventh and twelfth 

 thoracic, the first lumbar, and the second and third sacral 

 segments of the spinal medulla. Reference to the description 

 of the nerve-supply of the large intestine will show that it is 

 also innervated from the same segments. 



Vesical Pain. Referred pains in connexion with the 

 bladder are not uncommon, and their distribution suggests the 

 probability that, whereas the internal trigone is supplied by 



