The Diaphragm. 167 



dome is on a level with the junction of the left sixth costal 

 cartilag-e with the sternum; from the side, this level is 

 seen to correspond to the seventh and eighth ribs, and, 

 from behind, to the ninth rib, while the central tendon is 

 on a level with the junction of the ensiform cartilage and 

 the sternum. 



Affections of the Diaphragm. -Diaphrag- 

 matic hernia occurs when the stomach or intestine pro- 

 trudes through the normal opening situated between the 

 muscular bundles arising from the sternum and those 

 from the ribs. This opening permits the passage of the 

 superior epigastric vessels in the normal state and is filled 

 with areolar tissue. Hernial protrusion is not confined to 

 this portion alone, but may take place elsewhere in the 

 diaphragm, through any abnormal opening the result of 

 some injury, such as a broken rib, etc. Pleurisy, when 

 limited to the portion of the pleura attached to the dia- 

 phragm, is termed diaphragmatic pleurisy, and is charac- 

 terized by severe pain in the region of the diaphragm 

 when this muscle is disturbed, as in respiration, with the 

 result that the patient tries as much as possible to prevent 

 any movement of it, so that the respirations are shallow 

 and principally thoracic. Locally, there is tenderness on 

 pressing upwards in the region of the tenth rib in this 

 affection. When the spinal cord is diseased at the levels 

 of the third and fourth cervical segment, or, compressed 

 in the same situation by a fracture or a dislocation of the 

 vertebrae, or when the phrenic nerve is severely affected 

 by a tumor, or aneurism, or by neuritis, paralysis of the 

 diaphragm results. The inability of the muscle to con- 

 tract, when the whole of it is paralyzed, causes the breath- 

 ing to be almost entirely thoracic, so that the abdomen is 

 retracted in inspiration and forced out in expiration, the 

 opposite of the normal conditions. The patient is unable- 



