Rhythmical contractile activity of amnion accompanies development reptiles and birds in the course of the large part of embryogenesis. These rhythmical contractions are myogenic and spontaneous. The strength, frequency, and character of the amnion contractions change in embryogenesis in a regular way. This type of rhythmical activity is sensitive to many neurotransmitters and external factors. Features of similarity and difference of the amnion rhythmical contractile activity in the reptile and bird embryogenesis are considered. There are discussed a possible functional significance of this rhythmical activity and its participation in response of embryo to external actions, such as temperature fluctuations and acute hypoxia.
Amnion Animals