Self-Test
Complex bleb forms
Many of the periderm cells seen in this scanning electron micrograph have more than one bleb projecting from their surface.
By week 15-16, periderm cells project complex blebs. The formation of the blebs greatly increases the cell surface area exposed to amniotic fluid. Tight - junctions exist between the cells suggesting a water-tight seal. This is considered the pinnacle of development of the periderm.