a 
1094 UROGENITAL SYSTEM: 
basal angles of the tetrahedron correspond to the bladder apex and to the two 
lateral angles. of the bladder or points where the ureters join the organ. The three 
surfaces, which meet inferiorly at the 
urethral orifice, are only marked off 
from one another by rounded borders, 
but as long as the organ is empty, or 
Infero-latera’ . nearly so, they are separated by dis- 
apes tinct borders from the superior sur- 
face. These three areas have been 
already described as the infero-lateral 
surfaces and the base of the bladder. 
Their relations have also been  in- 
dicated (Figs) 739 and 740).- The 
7 superior surface of the empty bladder 
Vee looks upwards into the pelvic cavity; it 
deferens jg convex when the organ is contracted, 
concave when relaxed. This surface 
- Bladder apex 
Urethra 
Ureter 
Seminal vesicle is covered by peritoneum, and its out- 
Fic. 740.—THE BLADDER, Prostate, AND SEMINAL line, which is approximately triangular, 
VESICLES, VIEWED FROM BELOW. is determined by lateral and posterior 
Drawn from a subject in which the viscera were hardened borders (Fig. 748). The lateral borders 
in situ. Same specimen as figure 741, A. The of the empty bladder are sharply 
bladder contained but a small amount of fluid. So ri 
marked, and extend from the bladder 
apex to the lateral angles of the bladder, or points where the ureters join the organ. 
The lateral borders separate the superior from the infero-lateral portions of the 
under aspect of the bladder wall (Fig. 741, A). The posterior border stretches across 
between the lateral angles of the bladder, and separates the superior from the basal 
surface of the viscus. The superior surface is related in the male to coils of intestine ; 
in the female it is also related to the anterior surface of the uterus. The lateral 
border of the empty bladder les against the pelvic fascia just above, or at the level of, 
the upper limit of the levator ani muscle. The vas deferens crosses the side wall of 
the pelvis parallel to it, but at a considerably higher level. In mesial section the 
; ; Vas deferens — 
Superior surface / 
Ureter of bladder 
Vas ( ( 
deferens” \ 
Seminal 
vesicle” 4 Sigg Urachus Semin 
Urachus 
Infero-lateral 
area of bladder 
Lateral aspect 
of prostate” Lateral 
aspect of 
prostate 
Infero-lateral 
a —— Urethra area of bladder 
( -—— Urethra 
A B 
Fic. 741.—THE BLADDER, PROSTATE, AND SEMINAL VESICLE, VIEWED FROM THE OUTER SIDE. 
Drawn from specimens in which the viscera were hardened before removal from the body. In A the bladder 
contained but a very small quantity of fluid; in B the quantity was somewhat greater. In A the 
peritoneum is shown covering the upper surface of the bladder, and its cut edge is seen where it is 
reflected along the lateral border of the organ. In B the level of the peritoneal reflexion is indicated 
by a dotted line. 
cavity of the empty and relaxed bladder often presents the appearance of a Y-shaped 
chink, the stem of the Y being represented by the urethra as it leaves the organ, 
and the two limbs by the narrow intervals between the superior surface and the 
under parts of the bladder wall which lie in front of and behind the urethral 
orifice. This relaxed form is sometimes described as the diastolic condition of the 
empty bladder, and is found associated with a bladder wall of but little thickness, 
anda concave upper surface. The condition is usually the result of an escape of 
