528 THE THORAX AND VERTEBRAL COLUMN 



spinal anaesthesia,, the level of the anaesthesia may be roughly 

 regulated by the position of the patient after the injection. 

 Where it is desired to reach a high level, the patient may be 

 placed flat upon the back, but with the head and neck flexed lest 

 the centres in the medulla oblongata become affected. 



Injuries of the Vertebral Column and the Spinal 



Dens f 



Foramen in transverse ._ 

 process 



Joint between articular 

 processes 



Inferior articular pro- 



cess of 4th cerv. vert. 



Position of emerging 



C- 5 



Articular process of 

 5th cerv. vert. 



Pointer in interverte- 

 bral foramen 



FIG. 162. Unilateral Rotatory Dislocation of the Fourth Cervical Vertebra. 

 The inferior articular process of the fourth cervical vertebra has slipped 

 forwards over the superior articular process of the fifth. In this position 

 it usually presses upon the fifth cervical nerve and causes pain which is 

 referred to the areas supplied by its terminal branches. 



Medulla. The cervical part of the vertebral column most 

 frequently suffers injury since it normally possesses the greatest 

 range of movement. Slight injuries of the vertebral column 

 may produce serious results owing to the delicate structure of 

 the spinal medulla. 



Unilateral, rotatory luxation of an articular process 

 may occur as the result of a sudden twist or bend, and may be 



