218 The Spinal Cord 



except in the area of distribution of the supra-clavicular nerves 

 (p. 146), becomes anaesthetic. (The phrenic nerve comes from the 

 third, fourth, and fifth nerves, chiefly the fourth, which passes out above 

 the fourth cervical vertebra.) When the lesion is in the mid-cervical 

 region the diaphragm acts imperfectly and the whole of the brachial 

 plexus is paralysed, as are, of course, all the nerves below. Death 

 rapidly closes the scene. At the second, third, or fourth cervical vertebra 

 the diaphragm, intercostals, and all other muscles of the trunk and 

 extremities are paralysed ; sensation may persist for a while in the 

 upper part of the neck and in the face, but immediate death is the 

 general result. 



In the case of a man with a tumour of the dura mater, which 

 pressed upon the back of the cervical cord, giving rise to agonising 

 girdle-pains and paraplegia, Mr. Horsley removed the laminas of the 

 vertebrae, from the third to the sixth, opened the dura mater, and 

 successfully removed the growth. 



It has been remarked elsewhere (p. 411) that the centre for micturi- 

 tion and defcecation is in the lumbar enlargement. When the cerebral 

 control is cut off, as in compression of the cord, the patient * passes 

 everything beneath him.' That is to say, he empties the bladder and 

 rectum without intent or even knowledge. As soon as the viscus gets 

 full the stimulus is conveyed to the grey matter of the cord and passes 

 out as a motor influence to the muscular tissue of the viscus. Let it 

 be remembered that these viscera, though containing non-striated mus- 

 cular tissue, are under cerebro-spinal and not merely sympathetic con- 

 trol. (See fourth sacral nerve, p. 378.) When the centre for micturition 

 is itself destroyed, as in extensive lesion of the lumbar enlargement, 

 or in disease of any part of the circuit, reflex is lost, and the bladder 

 quietly fills and overflows. 



The grrey matter in a cross section of the cord is seen as two 

 crescents with their convex borders joined by a transverse band. This 

 commissure is exposed at the bottom of the posterior median fissure 

 by separating the lateral halves of the cord, but it is shut off from the 

 bottom of the anterior fissure by a trafisverse band of white tissue. 



The posterior horn of the grey crescent tapers to the surface at the 

 postero-lateral fissure through which are issuing the sensory roots of the 

 spinal nerves. The anterior cornu is thick and tuberculated, and does 

 not reach the surface of the cord, the anterior roots of the spinal nerves 

 passing into it through the anterior column. That part of the lateral 

 half of the cord which the tapering posterior cornu cuts off constitutes 

 the posterior column, that part of it which lies close along the median 

 fissure being called the posterior median column or GolTs column. 

 Disease of this column gives rise to no known symptoms. 



Large, multipolar, g-anglionic cells occupy the anterior cornu ; 

 they regulate the movements of the muscles, and preside over their 

 nutrition as well as over that of the muscles and bones. The trophic 



