Sport picture of the day: Laurine van Riessen’s spectacular evasive action
Laurine van Riessen of the Netherlands rides on the barrier wall with Virginie Cueff of France after avoiding a crash during the second heat of the keirin race first round, at the Olympic velodrome in Rio de Janeiro
White blood cells help us fight off infections and diseases by literally chasing down and attacking bacteria, viruses, and germs that invade our bodies. In this video, a white blood cell chases and engulfs a bacteria. Make sure you watch until the end.