Operation (game) around the United States. It consists of an "operating table", lithographed with a comic likeness of a patient (nicknamed "Cavity Sam") with a large red lightbulb for his nose. This could be a reference to classic cartoons, where ill characters' noses turn red. In the surface are a number of openings, which reveal cavities filled with fictional and humorously named ailments made of plastic. The general gameplay requires players to remove these plastic ailments with a pair of tweezers without touching the edge of the cavity opening. "Operation" includes two sets of cards: The "Specialist" cards are dealt out evenly
Body cavity cavity closes, except in the region of the connecting stalk. Here, the gut tube maintains an attachment to the yolk sac. The yolk sac is a membranous sac attached to the embryo, which provides nutrients and functions as the circulatory system of the very early embryo. The lateral body wall folds, pulling the amnion in with it so that the amnion surrounds the embryo and extends over the connecting stalk, which becomes the umbilical cord, which connects the fetus with the placenta. If the ventral body wall fails to close, ventral body wall defects can result, such as ectopia cordis,