524 



DISSECTION OF THE PELVIS. 



THE BLADDER. 



After the bladder lias been separated from the surrounding parts its 

 form and the extent of its different regions can be more conveniently 

 studied. 



Whilst the bladder is in the body, it is conical in shape, and rather 



flattened from before backwards ; but 

 out of the body it is more circular than 

 when in its natural position, and it loses 

 that arched form by which it adapts it- 

 self in distension to the curve of the 

 pelvis. 



If this viscus is moderately dilated, 

 it measures about five inches in length, 

 and three inches across (Huschke). Its 

 capacity is greatly influenced by the age 

 and sex, and by the habits of the indi- 

 vidual. Ordinarily the bladder holds 

 about a pint without inconvenience dur- 

 ing life, though it can contain much 

 more when distended. As a general 

 rule it is larger in the female than in 

 the male. 



STRUCTURE. A muscular and a mu- 

 cous coat, with an intervening fibrous 

 layer, exist in the wall of the bladder : 

 at certain parts the peritoneum may be 

 also enumerated as a constituent of the 

 wall. The vessels and nerves are 

 large. 



The imperfect covering of peritoneum 

 has been described (p. 504). 



The muscular coat is formed of thin 

 layers of unstriated muscular fibres, viz., 

 an external or longitudinal, a middle or 

 circular, and an internal or submucous. 

 The longitudinal fibres (fig. 17!), ') 

 form a continuous covering, with the 

 usual plexiform disposition of the mus- 

 cular bundles, and extend from apex to 

 base. Above, some are connected with 

 the uraelius, and the subperitoneal 

 fibrous tissue. Below, the posterior 

 and lateral fibres enter the prostate; 

 whilst the anterior are attached to the 

 fascia covering the prostate, with the 

 exception of a fasciculus on each side, 

 which is united to the hack of the pubes 



through the anterior true ligament of the bladder. On the front and back 

 of the bladder the muscular layer is stronger, and its fibres more vertical 

 than on the lateral parts. Sometimes this outer layer of fibres is called 

 detrnsor urince from its action in the expulsion of the urine. 



The circular fibres (fig. 170, 2 ) are thin and scattered on the body of 



MUSCULAR FIBRES OF THE BLADDER, PROS- 

 TATE, AND URETHRA. 



1. External or longituiiinal fibres of the 



bladder. 



2. Circular fibres olf the middle coat. 



3. Submucous layer. 



I. Muscular layer around the urethra. 



o. Circular fibres of the prostate and ure- 

 thra continuous with the circular of 

 the bladder, 



6, 7. Septum of the corpus spongiosum. 



8. Corpus spuriL'iosum. 



9. Corpus cavernosum. 



10. Ureter. 



