This is a time-lapsed sequence of a region of the yolk sac of an embryonic kill-fish that is about 2 days old. Blood vessels are forming, and over the period of several hours (here compressed to a minute or two) you see the first cells to travel through these newly-made vessels. The clock in the upper left-hand corner allows you to watch for certain events. At 9:07, the first blood cell to move through these new vessels appears. These very young embryonic blood cells are rounded, and often bleb. At 9:35, near the center of the screen, a small group of blood cells appears to get stuck in an unfinished blood vessel. The endothelial cells remodel, and the vessel opens up.At 10:14 the recording speed was changed, so that events appear to happen much closer to real time. The cells look like they are drifting slowly through the vessels, as the young heart just starts to pump. At 11:28, the time compression is once again set so that events are greatly speeded up, and the dynamics of blood cell movement are obviousComponente Curricular::Educação Superior::Ciências Biológicas::Biologia Geral