348 



PKACTICAL PHYSIOLOGY. 



rhythm is produced by heating the ventricle, but each ventricular 

 contraction is augmented. 



The observation of the local effect of warmth may be carried out 

 equally well on a heart recorded by the ordinary suspension method. 



CHAPTEE XXY. 

 DISSECTION OF THE CARDIAC NERYES. 



Dissection of the Cardiac Nerves in the Dead Rabbit. After 

 moistening the fur over the neck of a rabbit cut it short. Make an 

 incision in the mid-line from larynx to sternum and pull apart the skin 

 flaps. Separate the sterno-laryngeal muscles from the sterno-mastoid 



Fio 229 Dissection of the vagus, the depressor, and cervical sympathetic nerves 

 in the rabbit. (Livon.) 



along one side of the trachea and expose the carotid sheath. Look for 

 three nerves running alongside of (Ca) the carotid artery: (P.n.) the 

 vagus, this is the largest ; (Dep) the depressor, a fine nerve which may 

 be traced up to where it arises by two branches, from the superior 



