[Extraembryonic motor activity during embryogenesis of higher vertebrates]

Rhythmic motor activity of the extra-embryo structures as well as the embryo motor activity play a major part in normal development of higher vertebrates. When comparing birds and mammals, a trend towards complication of the motor activity regulation is observed. Reptiles as a class of the vertebrates have not been studied enough in this respect. Apart from the regular changes of extra-embryonic rhythmic motor activity, there are some changes in this activity depending on alterations of environmental factors (temperature, gas composition of air, etc.). The extra-embryonic rhythmic motor activity seems to take part in adaptation of the embryo to changing environmental conditions thus maintaining homeostasis of developing embryo.