HANDItooK OF I'HVSIOLOGY 



NEIROI'IIYSIOLOGY III 



regeneration, 1017 



thyrotrophic secretion after, 1020, 1021 

 Placing reactions 



release of, 792 

 Plantai reflex 



pyramidotomy and, 839 



I'lastn.i 



osmotic pressure, relation to aqueous 

 humor, 1770 

 Plasmalogen 



structural formula, 1 711b 

 Plasticity 

 description, 1698 



in central nervous system adaptivity, 

 1698 

 Pneumotoxic centi c 



in pons, 960, I 1 13 

 pO ; : see Oxygen tension 

 Polarization 



see also Depolarization; Postsynaptic 

 potentials 



d.c. potentials and, 316-327 

 Polarized light : see Arthropods 

 Polypnea 



stt also Hyperpnea, Panting; Respiration 



body warming and, 1 182 

 Pons 



apneustic center, [ 1 13 



integration of vital regulation, 958 



lesions, 1565 



pneumotoxic center, 960, 1113 



respiratory renters in, 1 1 12 



section, activation and, 1565 

 Positive stimulus 



definition, 1475 

 Postcentral cortex: stt First somatic 



cortical field 

 Postcentral fields: see First somatic cortical 



field 

 Push entral homologue u-r first somatic 



cortical field 

 Postdischarges m Epileps) 

 Posterior nuclear thalamic group: see 

 Thalamic nuclei 



Posterior orbital cortex: t« 1 >i Iniuinsulo- 



temporal cortex 

 Pi>si. 1 101 pituitary, mi:ii [O34 

 see also Pituitary gland; Anterior 



pitiiit.ii \ 

 n h 1 11, il medullai \ hoi tnones, 1 033 

 as a trigger /one, 1 749 

 1 .1. 11 .< 1 1 1 smol ii pi essui e and, 103] 

 connections with hypothalamus, 1029 

 depletion ol aeurosecretorj material in, 



1049 

 exti .11 1, bod) tempo ature and, 1 189 



luii. turn, IO53, 1 u-, 1 



Inn moncs, structural formulas 



inn. ■ ItKMl 030 



in 1 miiis , ontrol ui .,i, 

 reflex activation, 1030, 1 033 



subdivisions, 1009, iu.ii 

 supraopticohypophyseal tract and, 1052 

 Postexcitatory depression 

 definition, 309 

 factor affecting, 309 

 Postsynaptic membrane: see Synapse, 



postsynaptic membrane 

 Postsynaptic potentials, 65-71, 150-190 

 anatomical considerations, 302 

 anoxia and, 302 

 changes in amplitudes, 189 

 character and nature of transmitter, 



166 

 definition, 149 

 depolarizing, 1 73 



central excitatory state and, 164 



hyperpolarization and, 189 



properties of, 151 



spatial considerations, 182 

 during depolarizing, 158 

 electrical stimulation and, 153 

 excitatory, 65, 152 

 factors affecting, 167 

 generation site, 150 

 genesis of, 166 

 gradation of, 167 

 hyperpolarizing, 151, 158 



central inhibitory state, 164 



depolarization and, 189 



spatial considerations, 182 

 hypothermia and, 302 

 inhibitory, 6g, 152 

 interrelation with spikes, 152, 170 

 latency, 162 



mechanical pressure and, 302 

 mode of spread, 165 

 nature, 1 50 



pyramidal neurons and, 303 

 reversal of, 160 

 standing 



1 1. 1 11 Him effects, 189 



nonpropagated, 164 



transfer to electrically excitable mem- 

 brane, 168 



trauma and, 302 



types of, 151 , 1 72 

 Postural reflexes 



see also Labyrinthine reflexes; Righting 

 reflex; Tonic neck reflexes 



central facilitation, 1075 



in spinal animal, 784 



reticular influences and, 107b 



mil- ul mi nil in, 557 



spm.il .ill. 1 ml milium is and, 1075 



vestibular mechanism and, 560, 1075 

 Postural tonus 



definition 

 Posture 



adjui in . U77. 1078 



afferent! in, 1078 

 central levels, 1078 

 in in. ui, 1 078 



afferents 



alpha and gamma, 1077 



from joints, 1070 



from muscle, 1068 

 afferents concerned, 1068-1071 

 alpha efferents and, 1077 

 center of gravity, 1 074 

 central aspects, 1075-1079 



cutaneous receptors and, 1070 



diencephalic structures responsible, 892 



efferent side, 1071 -1075 



endocrines, 1076 



enteroreceptors, 1 07 I 



Group II libers and, q44 



integration by reticular formation, 902 



in man, ontogeny, 905 



maintenance in man, 1074 



mesodiencephalic structures respon- 

 sible, 891 



motor innervation of spindles and, 1076 



muscle and ligament, elasticity and, 

 1074 



muscle plasticity and, 1067 



patterns of motoneuron activation, 

 1071, 107a 



relations to locomotion, 1079 



reticular formation and. [291 



role of extrapyramidal motor system, 

 901 



space perception and, [62g 



species difference in regulation, 902 

 Potassium 



conductance, 62, 1 18 



excitation and, 62-65, 118, 119 

 resting potential and, 168 



EEG and, 1880 



neural activity and, 1823 



ratio to calcium, brain function and, 

 1878 

 Potassium theory 



evidence against, 1 18 



resting potential and, 1 1 7 

 Praxic function 



definition, 1690 

 Prehension 



apparatus of phytogeny, 1680 



mechanical conditions, 1682 



Prepotenti.il 

 definition, 304 



Pressor mechanisms 



see also Vasomotor mechanisms 

 pathways, in spinal cord, 956 

 receptors, influence on respiration, 

 1 1 24 



Pressure, intra-abdominal: in Intra- 

 abdominal pressui e 



Pi rs\ naptic impulse 

 run ts un postsynaptic region, 163 



Presynaptic membrane: r« Synapses, 

 pi esynaptic membi ane 



Pi rs\ naptic potential 

 anatomical 1 onsida ations, 30a 



Volume I pages 1 780 Volutin 11 I ; ' '•/■/" 



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