Organ transplants can save countless lives, but sometimes they don't work as planned. Why does your body reject things? Watch More: How Smart Is Your Body? ►►►► https://www.youtube.com/watch?v=sl7dcxzVHag Support Life Noggin on Patreon: https://www.patreon.com/LifeNogginStudios?ty=h Follow Us! https://twitter.com/LifeNoggin https://facebook.com/LifeNoggin Click here to see more videos: https://www.youtube.com/user/lifenoggin Life Noggin is a weekly animated educational series. Whether it's science, pop culture, history or art, we explore it all and have a ton of fun doing it. Life Noggin Team: Director/Voice: http://lifenogg.in/patgraziosi Executive Producer: http://lifenogg.in/IanDokie Director of Marketing: http://lifenogg.in/JaredOban Animation by Steven Lawson Head Writer: http://lifenogg.in/KayleeYuhas Sources: https://medlineplus.gov/ency/article/000815.htm https://web.stanford.edu/dept/HPS/transplant/html/chronic.html https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2778785/ https://www.ncbi.nlm.nih.gov/books/NBK27163/ http://www.cts.usc.edu/hpg-heartvalvesurgery.html http://www.heart.org/HEARTORG/Conditions/More/HeartValveProblemsandDisease/Options-for-Heart-Valve-Replacement_UCM_450816_Article.jsp#.WNwNZdXytaR https://www.fda.gov/BiologicsBloodVaccines/Xenotransplantation/ http://www.smithsonianmag.com/innovation/future-animal-to-human-organ-transplants-180956402/ http://apps.engr.utexas.edu/ethics/organTransplant/nihxeno1.cfm https://www.technologyreview.com/s/540076/surgeons-smash-records-with-pig-to-primate-organ-transplants/ Written by: Michael Sago https://twitter.com/michaelsago