1053 



Uric acid, 63, 846 

 in spleen, 828 

 significance of, 846 

 Uricolytic enzyme, 849 

 Urinary bladder, movements of, 854 

 nerves of, 856 

 pigments, 841 

 Urination, physiological mechanism 



of, 853 

 Urine, composition of, 839 

 nitrogenous excreta of, 841 

 origin of acidity of, 836, 839 

 reaction of, 839 

 secretion of, 830 

 pressure of, 834 

 Uterus, changes of, during menstrua- 

 tion, 977 

 effect of, on mammary glands, 992 

 Utriculus, function of, 410 



Vagus nerve, action of, on gastric 

 secretion, 770 

 on heart, 572. See also Inhibi- 

 tion, 

 on pancreas, 784 



as motor nerve to stomach, 720 



nucleus of, 246 



relations of, to respiratory cen- 

 ter, 686 

 Valin, 789, 1019 



Vasomotor fibers, centers for, in cord, 

 606 



in brain, 626 



to pulmonary arteries, 615 

 nerves, action of, in heat regula- 

 tion, 962 



course and distribution, 597, 607 



general properties of dilators, 608 



history of discovery of, 593 



methods used to demonstrate, 594 



of heart, 614 



position of constrictor center, 600 



reflex actions of, 602 



rhythmical action of constrictor 

 center, 606 



to abdominal organs, 628 



to dilator center and reflexes, 609 



to genital organs, 628 



to head, 626 



to kidneys, 837 



to skeletal muscles, 629 



to trunk and limbs, 627 



to veins, 630 



Vasomotor nerves, tonic activity of, 



600 

 Veins, vasomotor supply of, 630 

 Velocity of blood-flow. See Circula- 

 tion. 



pressure in blood-vessels, 508 

 Venomotor nerve-fibers, 612 

 Venous blood-pressures, 504 



cistern, 514 



pulse, 525 



in brain sinuses, 623 

 Ventilation, principles of, 661 

 Ventricle. See Heart. 

 Veratrin, effect of, on muscle, 31 

 Vernix caseosa, 862 

 Vestibular nerve, 211 

 Vestibulospinal tract of spinal cord, 



180, 232 

 Villi, intestinal, movements of, 725 

 Vision. See Eye and Retina. 

 Visual acuity, 339 



center in cortex, 206 



field, binocular, 369 

 monocular, 338 



fields, conflict of, in binocular vision, 

 372 



purple, 334 

 Vital capacity, 646 

 Vitamins, 736, 902 

 Volume curve of heart, 543 

 Voluntary muscular contractions, 46 

 Vomiting, 730 



Wallerian degeneration, 123, 162 



Warm spots of skin, 277 



Water, absorption of, in stomach, 781 

 excretion of, 853 



Water-soluble B, 904 

 I C, 904 



i Weber-Fechner law, 281 

 j Wharton's duct, 747 

 i Wirsung, duct of, 783 



Work done by contracting muscle, 41 



Xanthin, 64, 846 



oxidase, 849 

 Xanthoproteic reaction for proteins, 



1022 



Zymogen, 744 

 granules, 755 

 Zymoids, 741 



