Accession Number : AD0722114

Title :   Physical Properties of Fluids and Structures of Vestibular Apparatus of the Pigeon.

Descriptive Note : Research paper,

Corporate Author : DEFENCE RESEARCH ESTABLISHMENT TORONTO DOWNSVIEW (ONTARIO)

Personal Author(s) : Money,K. E. ; Bonen,L. ; Beatty,J. D. ; Kuehn,L. A. ; Sokoloff,M.

Report Date : 15 JAN 1970

Pagination or Media Count : 9

Abstract : At pigeons' body temperature (44 C) endolymph has a specific gravity of 1.0017 and a viscosity of 1.19 cp (roughly twice the viscosity of water). Perilymph has a specific gravity of 1.0006 and a viscosity of 0.76 cp. No difference between the specific gravity of the cupula and the specific gravity of endolymph could be detected. The specific gravity of cut lengths of the membranous semicircular ducts with enclosed endolymph is 1.03. On the basis of these findings, it appears that gravity and linear acceleration cannot act directly on the cupula, but they could cause movement or distortion of the membranous labyrinth with resulting endolymph movement and cupular deflection. It is suggested that the semicircular canal reacts quite differently to small and to large stimuli: in response to small angular accelerations, only the proximal part of the cupula (near the hair cells) moves; in response to large angular accelerations, the cupula bends in the classical way and most of the movement is at the distal end. (Author)

Descriptors :   (*VESTIBULAR APPARATUS, *STRESS(PHYSIOLOGY)), (*BODY FLUIDS, VESTIBULAR APPARATUS), (*LYMPH, VESTIBULAR APPARATUS), ANATOMY, PIGEONS, EXPERIMENTAL DATA, EAR, SEMICIRCULAR CANALS, ACCELERATION TOLERANCE, THRESHOLDS(PHYSIOLOGY), NYSTAGMUS, GRAVITY, VISCOSITY

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE