A finger-like process of cytotrophoblast (Cyto.) is seen in this section growing centripetally through the chorionic mesoderm. A small crescentic mass of syncytium (Syn.) has differentiated on the tip of the process. The intervillus spaces are lined with syncytium, which reveals a distinct "brush border." Section 204. X150.
Fig. 19. Heuser et al., 1945.
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Keywords: brush border, chorionic mesoderm, cytotrophoblast, intervillus space(s), syncytium
Source: The Virtual Human Embryo.