THE TESTICLES 



1028 



Vessels and Nerves. — Tlic arteries of \hv prostate arise from the adjacent 

 vesical and lueniorrhoidal vessels. 'I'Ih' prostatic veins receive the dorsal vein oi 

 the penis, and after forming a plexns ( plexus of Santorini) investing the anterior 

 and a portion of the lateral surfaces, terniinate in tiie adjacent vesical veins. The 

 lymphatics end in the ])elvie glands, and a small gland may sometimes ))e foimd 

 on each side near the base of the organ. Tlu; nerves are d( rived from tin' 

 hyi)og;istric plexus. 



THE TESTICLES AND THEIR APPENDAGES AND COVERINGS 



The two testicles lie in a common pouch of integument called tlie scrotum, and 

 each organ is invested in addition by a series of coverings Avliich join in the middle 

 line to form a septum scroti. There are three ])rincipal layers: an outer (the 

 dartos) of unstrijxHl muscular fibre, a middle (the cremasteric) containing strijicd 

 nuiscular fibre, and an inner serous (tlie tunica vaginalis), separated from each 

 other by layers of connective tissue. The coverings (tig. G21), named from without 

 inwards, are (1) the dartos ; (2) the external spermatic fascia ; (3) the cremasteric 

 or middle spermatic fascia ; (4) the internal spermatic fascia ; (o) subi^eritoneal 

 fascia ; and (6) the tunica vaginalis. 



Fig. 621. — IIokizoxtal Sectiox of the Scrotum and Testicle. (Diagrammatic.) 



Septum scroti 



MEDIASTINUM TESTIS 



VAS DEFERENS 



- Skin 



Dartos 



External spermatic fascia 



Cremasteric fascia 



- — Parietal layer of tunica vaginalis 



=7—;^ — Internal spermatic fascia and 

 subperitoneal fascia 



Cavity of tunica vaginalis 

 Visceral layer of tunica vaginalis 

 Tunica albuginea 

 Digital fossa 

 EPIDIDYMIS 



THE SCROTUM. — Tlie scrotal integument is more or less pigmented, and 

 covereij in the adult with coarse, scattered hairs, and provided with strongly devil- 

 oped sebaceous and sudoriparous glands. It presents in the middle line a longi- 

 tudinal impression, the raphe, from which start on either side a multitude of 

 transverse wrinkles, efl"aceal)le by distension. 



(1) The dartos is a thin reddish layer composed of elastic tissue freely inter- 

 mingled with unstriped muscular fibres. It is adherent to the deep surface of the 

 skin, but passes inward septally betAveen the two testicles, forming a sejiarate sac 

 for each, and is prolonged over the penis and perina-iun. Its fibres assume various 

 directions, but for the most part run longitudinally at right angles to the scrotal 

 wrinkles, of which they are the cause. They are always moderately contracted in 

 health, and contract still more under the influence of cold and of mental emotion, 

 but are not affected l)y electricity. They ]>eeome relaxed in conditions of general 

 enfeei)lement. According to Barrois. the dartos is divided int<i two layers, the 

 more superlicial Ix'ing connnon to l)oth testicles, while the de(^]M'r and stronger 

 forms a separate investment for each testicle. an<l assists in the formation of the 

 septum scroti. 



(2) The external spermatic or ' intercolumnar ' fascia consists of a fatless, 

 laminated C(nmeetive tissue, within and closelv adherent to the darttxs, blending at 



