1. Department of Histology and Embryology, Wroclaw Medical University, 50‑368 Wroclaw, Poland
2. Department of Anatomy, Wroclaw Medical University, 50‑368 Wroclaw, Poland
3. Department of Thoracic Surgery, Wroclaw Medical University, 50‑368 Wroclaw, Poland
4. Department of Pulmonology and Lung Cancer, Wroclaw Medical University, 50‑368 Wroclaw, Poland
5. Division of Ultrastructure Research, Wroclaw Medical University, 50‑368 Wroclaw, Poland