PERITONEUM. 



935 



point of the knife is properly lodged in the 

 groove of the staff, and by the latter that it 

 follows the groove fairly into the bladder. 

 Some excellent instruments have been devised 

 to prevent the occurrence of so serious an acci- 

 dent, but to describe them here would be too 

 wide a digression. 



The lithotomist is liable to commit other 

 mistakes still in the same stage of the lateral 

 operation. His incisions may fall short of the 

 bladder altogether, leaving the prostate insuffi- 

 ciently divided ; or he may, on the other hand, 

 transfix the bladder by plunging his knife too 

 deeply. The former error may lead to disap- 

 pointment m extracting the stone, and to severe 

 injury of the neighbouring parts in the attempt 

 to do so ; it admits, however, of correction if 

 discovered in time, but the latter mistake must 

 be irreparable. Occurrences such as these 

 result from an imperfect knowledge of the 

 depth of the perineum, and may be accounted 

 for liy the great variation in this respect which 

 the region presents in different subjects. Du- 

 puytren and Velpeau found the distance from 

 the neck of the bladder to the integument of 

 the perineum to vary in different cases to the 

 extent of two inches and upwards, the disparity 

 depending chiefly on the degree of obesity of 

 the individual. 



The deep compartment of the anterior divi- 

 sion of the perineum has claims upon the 

 attention of the practical surgeon independent 

 of lithotomy. Matter sometimes forms within 

 this space, and from the contiguity of the 

 rectum on the one hand, and of the urinary 

 organs on the other, such collections produce 

 most distressing symptoms. The triangular 

 ligament of the urethra prevents the abscess 

 from gaining the surface directly, so that at 

 length it either bursts into the rectum or makes 

 its way gradually behind the base of the liga- 

 ment. The finger introduced into the gut affords 

 satisfactory information as to the nature of such 

 cases, and free incisions through the perineum 

 are followed by the most marked relief. 



Effusions of urine from accidental ruptures 

 of the urethra occur less frequently behind the 

 triangular ligament than in front of it, for in 

 the former situation the canal is so thoroughly 

 protected by its deep position that contusions 

 inflicted upon the surface of the region but 

 rarely affect it. False passages from the forci- 

 ble introduction of instruments take place in 

 general anterior to the triangular ligament; but 

 when the urethra gives way behind a stricture 

 in consequence of violent expulsive efforts of 

 the bladder, the urine sometimes escapes into 

 the deep compartment of the perineum, and 

 destructive consequences are sure to ensue 

 unless counteracted by timely treatment. 



Prostatic diseases are attended by a train of 

 symptoms which depend upon the sympathies 

 of neighbouring organs. When the gland sup- 

 purates (not an uncommon consequence of 

 acute inflammation), the matter usually dis- 

 charges itself by the urethra, the tough capsule 

 determining its route ; but at times the abscess 

 bursts into the rectum, or it may even point in 



the perineum after passing behind the base of 

 the triangular ligament. 



BIBLIOGRAPHY. The following authorities may 

 be consulted with advantage, in addition to the 

 various systems of descriptive anatomy. Abraham 

 Colles, A treatise on surgical anatomy, Dublin, 



1811. James Wilson, A description of two muscles 

 surrounding the membranous portion of the ure- 

 thra, Med.-Chir. Trans., vol. i, p. 175, London, 



1812. C. A. Key, A short treatise on the section 

 of the prostate gland in lithotomy, London, 1824. 

 Alf. A. L. M. Velpeau, Traite d'anatomie chirunu- 

 cale, on anatomic des regions, Paris, 1826. Wil- 

 liam Harqrave, A system of operative surgery, 

 Dublin, 1831. Ph. Fred. Blandin, Traite d'anato- 

 mie topogiaphique ou anatomie des regions, Paris, 

 1834. J. F. Mahjiiiane, Manuel de medecine ope- 

 ratoire, Pans, 1834. G. J. Guthrie, On two new 

 muscles of the membranous portion of the urethra, 

 Lond. Med. and Surg. Journ., 1833. Robert Har- 

 rison, The surgical anatomy of the arteries of the 

 human body, Dublin. Thomas Morton, The surgi- 

 cal anatomy of the perineum, London, 1838. Alf- 

 A. L. M. Velpeau, Nouveaux. elements de medecine 

 operatoire, Paris, 1835. 



(Robert Mayne.) 



PERITONEUM. The serous membrane 

 of the abdomen, investing the inner surface of 

 the abdominal walls and the outer surface of the 

 abdominal viscera, and forming, by duplica- 

 tion, sheets with both surfaces free, called 

 omenta, mesenteries, suspensary ligaments, 

 &c. 



The peritoneum of the male subject, in 

 accordance with the rule of serous membranes, 

 is a shut sac : in the peritoneum of the female 

 the single exception to this rule is met with: 

 here the Fallopian tubes open into the perito- 

 neal cavity, and their mucous surface is conti- 

 nuous, through their nmbriated extremities, 

 with the serous surface of the peritoneum. 

 Another circumstance that renders the female 

 peritoneum peculiar amongst serous mem- 

 branes is, that it is necessarily ruptured in the 

 occurrence of a normal process, namely, in 

 the escape of an ovum. 



The manner in which a single serous shut 

 sac, by a kind of intus-susception, invests 

 the external surface of viscera and the internal 

 surface of the cavity in which they are con- 

 tained, is admirably illustrated by the well- 

 known comparison of a double night-cap. 

 Where the cavity contains only a single, viscus 

 of a simple rounded form, as, for instance, 

 the pericardium containing the heart, the com- 

 parison is very apt. But when, as in the case 

 of the abdomen, numerous viscera of irregular 

 shape are contained in the cavity, the matter is 

 much more complicated, and the resemblance, 

 therefore, far less striking. Yet is the relation 

 of the parietal part of the peritoneum to the 

 visceral part, and of both to the abdominal vis- 

 cera, essentially similar to that indicated in this 

 well-known simile. The complexity of the 

 peritoneal folds seems mainly to depend upon a 

 strict adherence to such a simple relation, in 

 the case of each of a great number of viscera, 

 with their vessels, &c. contained in a single 

 cavitv. Each viscus, whatever its shape, whe- 

 ther closely or loosely connected, must have its 



