EARLY EFFECTS ON DOGS OF SECTION OF THE EIGHTH CERVICAL SEGMENT OF THE SPINAL CORD AND THEIR BEARING ON SHOCK

Since it has been considered that nervous factors may play an important part in the production of surgical shock by lowering the blood pressure and impairing the circulation, it should be of interest to study the physiologic, morphologic and biochemical reactions in animals in which the blood pressure is lowered by the alteration in nervous function which follows section of the eighth cervical segment of the spinal cord. The most immediate general effects are motor and sensory paralysis distal to the level of section and vasomotor paralysis, complete except for the vasodilator fibers to the chorda tympani and glossopharyngeal nerves and the antidromic pathways of the posterior roots of the cervical nerves. After a brief initial rise there follows a marked fall of blood pressure, a slowing of the pulse and respiration, a fall of body temperature and a variable degree of depression or stupor, which usually wears off within