A variety of surface extensions are formed by BPAE cells. The small, narrow projections that extend out from the periphery of the cells like fingers are called filopodia. Functionally filopodia can serve in both a sensory and a locomotive capacity. The broad, flattened extensions that are particularly prominent along the leading margins of the cells are termed lamellipodia. These structures are extremely important for the motility of many animal cells, including BPAE cells, which produce crawling movements chiefly via the extension and contraction of lamellipodia.

Following mitosis, yet another type of protrusion from the surfaces of BPAE cells can be observed. Commonly known as blebs, small hemispherical mounds seem to bubble up from the exterior membranes of newly formed daughter cells. The rapidly appearing and disappearing lumps of material are remnants of the rounded form the parent cell assumes prior to division. The daughter cells lose the spherical shape as soon as they begin to settle and flatten on the substratum.

Sporadically throughout the video, small cytoplasmic fragments flow through the field of view. The cell debris, which can form following apoptosis or when migrating cells are forced to sever segments of trailing material in order to continue their advancement, are carried by currents in the culture medium. The currents are able to sweep along any fragments that are not sufficiently connected to the substratum. Strong anchorage points formed by most cells with the substratum prohibit the currents from carrying away entire cells.