INTESTINAL OBSTEUCTION. 369 



that tuberculous ulcers exhibit. An important collection of 

 lymphatic glands lies around the termination of the superior 

 mesenteric artery at the ileo-caecal angle. These glands are 

 involved secondarily to ulceration of the lower part of the 

 ileum, and by suppuration may give rise to peritonitis, since 

 they are immediately beneath the peritoneum. 



In summer diarrhoea and various infectious fevers other than 

 typhoid, considerable swelling and even ulceration of the 

 lymphoid tissue of the intestine may occur. 



Ulcers of vascular origin, girdling the intestine, are sometimes 

 met with as the result of embolism, thrombosis, syphilis, and 

 amyloid disease. The distribution of the arterial twigs which 

 supply the intestine is the basis of the transverse arrangement 

 of these ulcers. 



Ulceration of the Large Intestine. Although there are no 

 Peyer's patches in the large bowel, lymphoid tissue is plentiful, 

 particularly in the caecum and vermiform appendix. Ulcers 

 may arise in this tissue in many infective conditions, such as 

 typhoid fever, tuberculosis, and dysentery. So-called stercoral 

 ulcers are particularly apt to form in the caecum as the result of 

 chronic obstruction of the bowel, and certain metallic poisons, 

 like mercury and antimony, may, during the process of excretion 

 by the colon, originate ulceration. 



INTESTINAL OBSTRUCTION. 

 (Other than that due to Malignant Disease.} 



Strangulation by a band is an accident which is almost 

 exclusively limited to the small intestine, this part of the bowel 

 being more easily ensnared than the colon owing to its greater 

 mobility, smaller calibre, and coiled arrangement. 



Bands are usually adventitious structures which have resulted 

 from past inflammation or operation. They occur most fre- 

 quently in the lower part of the abdomen, in connection with the 

 vermiform appendix, the hernial orifices, the Fallopian tubes, and 



C.A.A. 24 



