1052 



Summation of muscular contractions, 

 43 

 of stimuli in nerve-centers, 137 

 Superior olivary body, relation of, to 



auditory paths, 213 

 Supplemental air, 647 

 Swallowing, 709 



respiration, 711 

 Sweat, amount and composition of, 

 858 

 nerve-centers for, 861 

 nerves, action of, in heat regula- 

 tion, 962 

 secretory fibers of, 859 

 Sympathetic nervous system, general 

 relations, 247 

 resonance, 395 

 Synapse, 129 

 Syntonin, 776 



Systole, duration of, in heart, 552 

 Systolic arterial pressure, 490 



determination of, in animals, 

 492 

 in man, 498 



Tabes dorsahs, 169 

 Tactile discrimination, 174 



localization, 283 

 Taste buds, 292 



center for, in brain, 216 

 nerves of, 290 



sensations, classification of, 292 

 specific energy of, 293 

 threshold stimulus, 295 

 sense of, 290 



stimuli, mode of action, 294 

 Tectorial membrane, 397 

 Telophragma, 20 

 Temperature. See Heat. 

 coefficient, 115 



effect of, on body metabolism, 936 

 on gases in solution, 668 

 on heart-rate, 591 

 on muscular contraction, 29 

 of human body, 951 

 sense, distribution and character- 

 istics, 276, 278 

 path for, in spinal cord, 173 

 punctiform distribution of, 276 

 Tension of gases in solution, 670 

 Tensor tympani muscle, function of, 



391 

 Tenth cranial nerve, nucleus of, 246 

 Testis, internal secretion of, 882, 883 

 Tetanus, number of stimuli necessary 

 for, 45 

 of muscle, 42 

 opening and closing, 92 

 Tethelin, 880 

 Theobromin, 847, 928 

 Third cranial nerve, nucleus of, 242 



Third heart sound, 551 

 Thirst, sense of, 289 

 Thoracic autonomics, 728, 729 

 Thorax as closed cavity, 637 



aspiratory action of, 655 



normal position of, 638 



origin of negative pressure in. 654 

 Thrombin, 454 



method of obtaining, 454 

 Thrombogen, 455 

 Thrombokinase, 458 

 Thromboplastic substances, 458 

 Thrombosis, 452 

 Thyroid, extirpation of, 865 



function of, 867 



internal secretion of, 864 

 Thyroxin, 869 

 Tidal air, 646 



Tigroid substance in nerve-cells, 134 

 Tissue protein, 894 

 Tissues, exchanges of gases in, 680 

 Tone (musical) of muscular contrac- 

 tion, 44 

 Tonicity of heart-muscle, 570 



of muscle, 50 



of nerve-centers, 151 

 Tonometer, 671 

 Tonus, myogenic, 56 



neurogenic, 56 

 Touch sense, path of, in cord, 173 

 Tract of Lissauer, 166, 167 

 Tracts in cerebellum, 232 



in spinal cord, 163 



of Flechsig, 165 



of Gowers, 165 



of Helweg (olivospinal), ISO 



of Monakow (rubrospinal), 179, 198 

 Traube-Hering waves, 607 

 Treppe in muscular contractions, 35 

 Trigeminal nerve, area of distribution 

 of, 245 

 nucleus of, 245 

 Tritanopia, 352 

 Trophic nerve-fibers, salivary glands, 



753 

 Trypsin, 742, 788 

 Tryptophan, 791, 902 

 Tlirck's method for reflex time, 148 

 Twelfth cranial nerve, nucleus of, 247 

 Tympanic membrane, 383 

 Tyrosin, 790, 902, 1019 



reagent, 1022 



Unconditioned reflexes, 189 

 Unipolar method of stimulation, 93 

 Unitarian theory (blood-corpuscles), 



440 

 Urea, formation of, in fiver, 825 



origin and significance of, 843, 1019 

 Ureters, contractions of, 853 

 Urethra, sphincter of, 855 



