854 THE SPINAL CORD. 



to below that after cervical transection, it might have been supposed that 

 suppression of urine would, for some hours at least, succeed the transection. 

 This, however, does not, in my experience, happen ; the secretion of urine, 

 if ever stopped, soon recommences, and the regular emptying of the bladder is 

 one of the earliest and constantly recurring cares required from the attendant. 



The vagus appears to be the afferent and efferent nerve to the pancreas, 

 but the common bile duct, though opening together with the pancreatic, 

 possesses afferent fibres from the spinal ganglia. If a small quantity of saline 

 be injected into the common bile duct so as to distend the duct, a reflex altera- 

 tion of arterial pressure results, of very marked and regular character ; the 

 afferent channels for this reflex pass through a large number of the thoracic 

 spinal roots, especially perhaps those from the sixth to the twelfth, and I find 

 the reflex not obviously lessened by section of both vagi. The liver and 

 bile ducts have frequently, from Haller's experiments onwards, been found 

 insensitive to artificial stimuli ; this and the insensitivity of the liver under 

 incision or puncture by the surgeon, both stand in contradiction to the 

 pains caused by biliary calculi. The ease and certainty with which mechanical 

 stimulation of the duct by a little fluid excites a strong vascular reflex, is 

 of interest in this connection. The reflex still ensues when the fluid is pre- 

 vented from entering the gall bladder. In the tench the musculature of 

 the intestine is of the striped variety, but no spinal reflexes involving it 

 can be found. 1 



Spinal reflexes affecting the musculature of the blood vessels. 

 On severance of cord from bulb, arterial pressure falls, owing to damage 

 done not to the innervation of the heart, 2 but to that of the blood vessels, 3 

 especially of the smaller arteries. Goltz earliest drew attention to the 

 partial character of the atonia of the blood vessels of the spinal frog, and 

 its conversion into completeness by destruction of the spinal cord. In 

 the dog he transected the spinal cord at the hind-end of the thoracic 

 region, and waited until vascular tonus of the hind-limbs was restored ; 

 destruction of the lumbo-sacral region of the cord he found then renew the 

 vascular dilatation in the hind-limb regions. Schlesinger 4 obtained in the 

 spinal rabbit, after doses of strychnin, slight reflex alterations in general 

 arterial pressure ; and similar have been sometimes obtained without the use 

 of strychnin. In the rabbit the reflex has given heightening of pressure, in 

 the dog depression. Nussbaum 5 obtained in the curarised spinal frog reflex 

 contraction of the blood vessels of the plantar web; Yulpian 6 obtained a 

 similar result in the crossed hind-limb, after transection of the spinal 

 cord of the dog in the mid-thoracic region, on stimulating the sciatic 

 nerve central to section of it; fall of temperature, as evidenced by a 

 thermopile and galvanometer, was taken as index of the vaso-constriction. 

 The same result has been noted in the rabbit. In order to obtain these 

 reflexes, the lower part of the thoracic region of the cord must lie below the 

 transection ; the lumbo-sacral region of the cord does not of itself suffice. 

 After spinal transection at the hindmost thoracic segment, Goltz 7 found 

 mechanical stimulation of the glans penis cause erection ; this result was not 

 obtained after subsequent destruction of the lumbo-sacral region of the cord. 

 Similarly, excitation of the sciatic nerve, proximal to its section, causes flushing 

 of the skin of the contralateral hind-foot. After spinal transection at the 

 third cervical level, excitation of the brachial plexus cords, proximal to their 



1 Mahn, Arch.f. d. ges. PhysioL, Bonn, 1899, Bd. Ixxii. 



2 v. Bezold, "Untersuch. ii. d. Innerv. d. Herzens," Leipzig, 1863, Bd. ii. 



3 Ludwigu. Thiry, Sitzungsb. d. k. Akad. d. Wissensch., Wien, Bd. xlix. S. 421. 



4 Med. Jahrb., Wien, 1874, S. 20 ; cf. also Smirnow, Centralbl. f. d. med. Wissensch., 

 Berlin, 1886 ; and Ustimowitch, Arch.f. PhysioL, Leipzig, 1880. 



5 Arch. f. d. ges. PhysioL, Bonn, 1874, Bd. x. S. 374. 



6 " Lecons sur 1'appar. vasomoteur, " Paris, 1875, p. 288. 



7 Arch.f. d. ges. PhysioL, Bonn, 1874, Bd. viii. S. 463. 



