[Occurrence of a special type of "polypoid cushion" and valve-like formations in arteries].

Intraarterial structures, known as 'polypoid cushions' and 'valve-like' projections at arterial branching sites, were observed in serial sections of human cleft lip and nasal mucous membrane biopsies. A particular type of 'polypoid cushions', which additionally contains a small artery in its center, is distinguished. It is suggested that both the particular type of 'polypoid cushions' and these 'valve-like' projections originate from the invagination of the entire vessel wall at arterial branching sites according to the location of the dissection or damage. The differences between these 'valve-like' formations and genuine arterial valves are mentioned.