Histological sections revealed considerable differences with respect to age. These differences are noticeable in all three parts. During the first days of adult life, the
thickness of the muscle layer and the glandular epithelium decreases. However, the degree of decrease is more pronounced in the glandular epithelium than in the muscle layer. The lumen, on the other hand, increases at the onset of adult life and reaches a maximum diameter of B540 mm at 9 d