1. 1Department of Histology and Embryology, Poznan University of Medical Sciences, Swiecicki Str. 660-781 Poznan, Poland
2. 2Department of Histology and Embryology, University of Medical Sciences, Poznan, Poland Regional Specialized Hospital in Wroclaw, Research and Development Center, Wroclaw, Poland
3. 3Department of Histology and Embryology, University of Medical Sciences, Poznan, Poland