EXPERIMENTAL PHYSIOLOGY. 



upper part of the cut nerve. Stimulate with an interrupted current 

 of moderate strength and watch the effect on the vessels and pupils. 

 If no change occurs, repeat with the other nerve. The nerve which 



FIG. 26. Dissection of neck of rabbit to show relative position of nerves, 

 etc.: (c) carotid artery; (ft) vagus; (5) sympathetic; (d) cardiac depressor; (m) 

 descending branch of hypoglossal nerve. (After Jackson). 



causes definite effects is the sympathetic. Explain the causes of 

 the results. It is often advisable to introduce the tracheal and 

 carotid cannulae, as directed under par. 3, before attempting to 

 stimulate the nerves. 



