508 BRUISES OF THE ABDOMINAL WALLS. 



SURGICAL DISEASES OF THE 

 ABDOMEN. 



The abdominal walls comprise the skin, yellow elastic tissue, a fibrous 

 aponeurosis, the muscles, a layer of fat, and the peritoneum. The muscles 

 partly overlap and cross one another, and have numerous tendinous 

 expansions. In herbivora the thick abdominal walls, which always appear 

 distended, have to support the bulky digestive viscera, and effectually 

 protect them from external injury, but render examination of them almost 

 impossible. Externally the abdominal walls are clothed with skin, pos- 

 sessing a well-developed subcutis, whilst internally they are lined with 

 peritoneum, which is continuous with that which invests the viscera. 

 The healthy peritoneum is smooth and shining, allowing the viscera to 

 play easily over one another ; but when inflamed, exudation occurs, and 

 the surfaces may become adherent. Except as a result of penetrating 

 wounds or severe bruising the abdominal organs are seldom injured from 

 without. Voulton (Stockfleth) found, however, the rumen of an ox 

 ruptured by a blow from a horse's foot. Death rapidly followed from 

 peritonitis. In horses ruptures of the spleen and liver have been observed. 

 The abdominal walls receive their blood from (a) the lumbar arteries 

 which enter between the lumbar muscles, pass across the abdomen, between 

 the outer and inner oblique muscles, and between the latter and the trans- 

 verse abdominal muscle, and communicate with the other vessels of the 

 abdominal parietes ; (b) the anterior abdominal artery which arises from 

 the internal thoracic artery and passes backwards ; (c) the posterior 

 abdominal artery which arises from the prepubic, takes a course close 

 below the peritoneum in the middle line, crosses the inner inguinal ring in 

 a forward direction, and anastomoses with the anterior abdominal and 

 lumbar arteries. 



I.— BRUISES OF THE ABDOMINAL WALLS. 



These occur rather frequently in the domestic animals, and are 

 caused by kicks, thrusts with the horn, by animals rushing together, 

 or by collisions with vehicles. The nature of the injury mainly 

 depends on the character of the injuring body, and the force with 

 which it is applied. Sometimes the walls are ruptured,— a condition 

 described later ; whilst the skin, on account of its greater elasticity, 

 remains intact. Sharp objects produce surface wounds, sometimes 

 perforate the abdominal walls, and may even penetrate the internal 

 organs. Bruises of the abdominal parietes from horn-thrusts, &c., 

 are frequent in herbivora, on account of the tension of the abdominal 

 walls ; and, as in other regions, are characterised by a subcutaneous 

 solution of continuity in the tissues and vessels. When small blood- 

 vessels and limited tracts of tissue are ruptured, more or less hard, 



