Biomedical subjects
Publications and source records attributed to S P Sirenko.
Mechanical processes and factors involved in gravireception of a plant cell qualitatively considered and their changes caused by microgravity and clinostat modeling conditions are discussed. It is supposed that the most of the cell microgravity effects as well as clinostat modeling effects on a cell may be attributed to the generalized unspecific reaction of a cell to external influence.
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This review discusses present-day concepts concerning the structure and function of semicircular canals of the vestibular apparatus. It is indicated that the data available today about the function of semicircular canals suggest that they should be considered as a system with distributed parameters and that particular attention should be given not only to canal-canal interaction but also to canal-otolith interaction. A special section is allowed for the discussion of an agreement between mathematical description of the behavior of semicircular canals and experimental data. This work is of theoretical and practical importance and can help clarify the potential role of semicircular canals in the development of space motion sickness.
This paper discusses the applicability of a previously developed model of endolymph movement in the semicircular canals of the vestibular apparatus for an adequate interpretation of experimental data concerning the effect of microgravity on thermal responses of the semicircular canal.
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A model of the otolith as a system with distributed parameters in which the otolith is described by a two-dimensional elastic plate fixed at its sides is presented. The behavior of the model in response to centrifugal and gravitational forces is discussed. Comparison of this model with experimental data yields the value of Young's module of the otolith membrane equal to 10(2)-10(3) dyne/cm2. It is shown that deformations of different compartments of the otolith are dissimilar even for a homogeneous otolith membrane, depending on its configuration and orientation relative to the force vector. It is concluded that intralabyrinthine pressure may be the cause of original nonhomogeneous deformation of hairs in receptor cells at rest.
A mathematical model of the time-course variations of the cupula of the semicircular canals of the vestibular apparatus is presented. The model is found to be in good agreement with experimental data which suggests that the cupular matter has viscosity-elasticity properties. Their role in the functioning of the vestibular apparatus is discussed in qualitative terms. The applicability of the membrane model to the description of the time-course variations of the cupula is considered.
This paper presents a mathematical model of time-course variations of the cupulo-endolymphatic system which can be described by the Steinhauzen phenomenological equation for the case of a unidimensional toroid, assuming that the densities of the cupula and endolymph are identical. If the densities are different, the time-course variations of the cupuloendolymphatic system may aggravate and manifest at the powered stages of space flight.
This paper describes a mathematical model of the otolith of mammals represented as a system with parameters of distribution. Two versions of the model are analyzed and the lowest frequencies of natural oscillations of the system are evaluated.