FUNCTIONAL MECHANISM OF THE PANCREAS. 385 



sympathetic fibers. The pancreas forming part of this same 

 system, the vascular as well as the nervous arrangement of 

 the latter are undoubtedly similar. Indeed, we can repeat 

 almost word for word the explanations given of the phenomena 

 observed under the same conditions when the stomach was in 

 question: i.e., the general motor mechanism (sympathetic) serves 

 only to maintain the tonic contraction of the vascular supply and 

 the immanent potentiality of the pancreas when it is in the passive 

 state, while the added impulses of the vagus excite and govern its 

 functional activity. 



The functional mechanism of the pancreas would now be 

 as follows: 



The nerve-supply of the pancreas is derived from two auton- 

 omous sources: the general motor system (sympathetic) and the 

 vagus system. 



The general motor system supplies efferent nerves, which only 

 serve to maintain tonic contraction of the arteries and to insure 

 the functional activity of all pancreatic structures during the 

 passive or resting period. 



The vagus system supplies loth sensory and motor nerves, 

 which excite and govern the functions of the pancreas during its 

 active period. 



The extrinsic efferent nerves of the pancreas, also derived 

 from the "general motor" and vagus systems, accompany the or- 

 gan's arterial supply and jointly constitute its extrinsic vasocon- 

 strictor system : i.e., that through which the Uood-flow in the organ 

 is increased. 



The intrinsic efferent nerves are divided into two sets: (1) 

 branches of the general motor system; (2) branches of the vagus 

 system. 



(a) Each branch of the general motor system subdivides into 

 two branches: one of these supplies the arterioles; the other sub- 

 divides into two branches, one of which is distributed to the mus- 

 cles and the other to the glands. 



(b) The branches of the vagus subdivide in the same manner 

 and inosculate with the general motor filaments and plexuses ex- 

 cept with those distributed to arterioles that supply capillaries to 

 the glands. 



When the pancreas is in the resting state, the general motor 



