CONTENTS xi 



PAGE 



Hvpothermia and the Nervous System — C. McC. Brooks 260 



Differential susceptibility of A, B, and C fibers. Excitability of nerve. Rate of rise 

 of action potential. Responsiveness of central nervous system in the cold. Dorsal 

 root potentials and reflex. Repetitive firing. Tetanus. 



Experimental and Clinical Observations on the U.se of Hypotliermia to 

 Prevent Ischemic Damage to the Central Nervous System — R. G. Pon- 

 tius and M. E. De Bakcy 2CA 



Thoracic aortic occlusion in dogs. Cord damage and survival. Human data. 



Discussion: 



W. H. Loiighccd 270 



Possibilities and Limitations of Dififerential I'.rain Cooling in Dogs — 



/. M. Jensen, W. M. Parkins, and H. M. Vars 271 



Inflow occlusion in dogs. Carotid arterial perfusion. Brain temperature versus jien- 

 eral body temperature. 



Discussion: 



]]'. M. Parkins, J. Cahn, and J. D. McMnrrey 274 



REVIEW AND APPRAISAL OF PARTS I AND II — /. W. Scveringhaus 279 



Metabolism. Temperature gradients. Temperature regulation. Nervous system. 

 Hemodynamics. Hematology. Respiration. Renal function. Endocrine -ystem. 

 Electrolytes. 



REVIEW AND APPRAISAL OF PARTS I AND II S. M. HoTVatll 2S4 



Variables in hypothermic experiments. Tolerance of homoiothermic animals. Elec- 

 trolyte shifts. Circulation. Oxygen consumption. 



Part III — Myocardial Irritability and Hypothermia 



Hypothermia and the Physiology of Cardiac Excitability — C. McC. Brooks. . 2><7 



The excitatory process. Hypothermia and heart rate. Pacemaker action ; propaga- 

 tion of excitation. Phases of excitability cycle identified by testing stimuli. Fibril- 

 lation as a response to excitation. Hypothermia and the initiation of a contractile 

 response. 



Temperature Effects on Cardiac Transmembrane Potentials — B. F. Hojfiuaii. M)2 



Transmembrane potentials of single cardiac fibers. Normal records, auricle, papil- 

 lary muscle, Purkinje system. Ionic basis of transmembrane potentials: ionic perme- 

 ability and ionic fluxes. Transmembrane potentials and excitability: threshold, 

 pacemaker activity, refractoriness. Effects of temperature : resting and action poten- 

 tial, rate and rhythmicity, refractoriness, conduction velocity. pH and pCOj. K 

 and Ca. 



[discussion: 



G. E. Burch, J. ]V. Scveringhaus, and D. Durrer \2A 



