1428 SUKFACE AND SUEGICAL ANATOMY. 



connective tissue and the space of Betzius, and ultimately ascend on the anterior 

 abdominal wall between the fascia transversalis and the parietal peritoneum. 



The bulbo-urethral glands, which lie immediately behind the membranous part of 

 the urethra, are overlapped by the bulb of the urethra, from which they are separated 

 by the inferior fascia of the urogenital diaphragm. The internal pudendal 

 artery lies just within the margin of the pubic arch. The artery to the bulb 

 runs transversely medially ^ in. above the base of the urogenital diaphragm, i.e. 

 above the level of a line drawn from the front of the tuberosities to the central 

 point of the perineum. 



The male urethra measures about eight inches from the external to the internal 

 orifice; the narrowest portion is at the external orifice; a second narrowing 

 occurs at the urogenital diaphragm. It is behind these constrictions that a 

 calculus is liable to become impacted. The most dependent part of the urethra 

 is the bulbous portion, and it is in this situation that an organic stricture is 

 most frequently met with. The membranous part of the urethra, situated between 

 the two fascise of the urogenital diaphragm, is surrounded by the sphincter urethrae 

 membranacese muscle, which, when thrown into spasm, may firmly grip an instru- 

 ment as it is passed into the bladder. Rupture of the urethra from a fall on 

 the perineum generally involves the bulbous portion. A. false passage made during 

 the passage of an instrument generally traverses the floor of the urethra at the uro- 

 genital diaphragm ; to prevent this the point of the instrument should always be 

 directed upwards, and the handle at the same time depressed as soon as the instru- 

 ment is felt to encounter the resistance of the inferior fascia of the urogenital 

 diaphragm. When the prostate is hypertrophied the prostatic part of the urethra 

 is elongated, and the internal orifice may look directly forwards, while if the lateral 

 lobes are unequally enlarged it may deviate laterally. Patients with prostatic 

 hypertrophy are seldom able to empty the bladder completely, on account of the 

 dependent well which exists behind the prostate. 



Cystoscopic Examination of the Bladder. On making a cystoscopic examina- 

 tion of the bladder special attention is paid to the trigone, as most of the patho- 

 logical lesions are associated with this region. At its anterior angle is the internal 

 urethral orifice, while at its postero- lateral angles are the small oblique slit-like 

 orifices of the ureters, surrounded by a very slight lip-like elevation of the mucous 

 membrane. At the base of the trigone the mucous membrane is raised into a 

 smooth transverse ridge which stretches between the ureteric openings, with a 

 slight forward convexity. The elevation is caused by a bundle of transverse 

 muscular fibres, continuous with the longitudinal fibres of the ureters. The 

 distance of the ureteric orifices from one another is rather more than an inch, 

 while their distance from the internal urethral orifice is slightly less than an inch. 



The urine is ejected into the bladder intermittently at intervals of a minute or 

 so. During each ejection the ureteric orifice is seen to pucker up, and as it relaxes 

 the gush of urine takes place in the form of a characteristic whirl "resembling an 

 injection of glycerine into water." The mucous membrane of the trigone is closely 

 connected with the subjacent muscular wall, so that it presents a smooth appear- 

 ance ; whereas over the rest of the- bladder it is thrown into folds owing to the 

 looseness of the submucous tissue. Further, the mucous membrane of the trigone 

 presents a pink injection, while over the rest of the bladder it is of a pale straw 

 colour. This contrast is due to the difference in the arrangement of the, blood- 

 vessels ; over the trigone they are larger, more numerous, and form a close network ; 

 hence, when this surface is inflamed, the congested vessels form a continuous vascular 

 layer. Over the rest of the bladder one sees, here and there in the mucous mem- 

 brane, small segments of fine vessels giving off a cluster of short branches, the finer 

 anastomoses of which are not visible when the mucous membrane is healthy. 



The form and shape of the trigone in women may be distorted by prolapse of 

 the bladder, by alterations in the size and position of the cervix, and by the 

 presence of fibroids. In the male, distortion is usually due either to the enlarge- 

 ment of the prostate or to disease of the vesiculse seminales. 



When the normal bladder is comfortably filled, the bladder walls appear 

 almost smooth, but when the bladder contracts the delicate muscular trabeculae 



