The authors stressed the anatomic characteristics of the head segment and its significance is the detection of small lesions in the pancreatic head.

Caterpillars move by a wave that starts at the back end of their body and sweeps through each segment until it reaches the head, pushing it forward.

Richard Salant, head of the news division, reminded Paley that the second segment had already been announced as airing on Monday and that our viewers would be expecting it.