126 



HUMAN EMBRYOLOGY AND MORPHOLOGY. 



THE PROSTATE. 



The Prostate is developed round the uro-genital sinus. It con- 

 sists of glandular tissue and stroma. 



(1) The glandular tissue is composed of tubular glands which 

 open into the prostatic part of the urethra. They are developed in 

 the 4th month, as series of solid buds from the epithelium lining 



bladder 



cord* '■ '_»^-< 



reter. 

 median lobe prostate 

 Wolffian duct 

 'aterat lobe prostate 



rectum 



aenit. tuber.' 



perineal, dep. 



Fig. 101. — A diagram to show the position at which the Prostatic Tubules arise. 



the upper part of the uro-genital sinus (Fig. 101). The buds grow 

 out as a right and left lateral mass, and form the glandular tissue 

 of the lateral lobes. At first the two lateral lobes, as in mammals 

 generally, lie separately behind the urethra. Then they fuse 

 behind the urethra ; in man only do they meet to form a dorsal or 

 pubic commissure over it. The third lobe (Fig. 91) appears later; 

 the tubular buds which form it rise from the posterior part of the 

 stalk of the bladder (Fig. 101) above the opening of the sinus 

 pocularis. It is not unfrequently absent or very small. 



Skene's tubules, which may be found opening into the urethra 

 of the female, probably represent prostatic tubules. 



(2) The Stroma of the Prostate. — While the glandular tubes 

 arise in three groups — two lateral and one posterior median — 

 from the epithelium lining the uro-genital sinus, and stalk of the 

 bladder — the muscular and fibrous elements arise from the meso- 

 blastic tissue surrounding the terminal parts of the Wolffian and 

 Miillerian ducts. The stroma surrounds the glandular tissue and 

 forms the peripheral part of the gland. It contains muscular 

 tissue which is especially developed in the pubic commissure. 



