WEBVTT 00:00:06.688 --> 00:00:09.778 Imagine two people are listening to music. 00:00:09.778 --> 00:00:10.615 What are the odds 00:00:10.615 --> 00:00:11.375 that they are listening 00:00:11.375 --> 00:00:13.180 to the exact same playlist? 00:00:13.180 --> 00:00:14.783 Probably pretty low. 00:00:14.783 --> 00:00:18.370 After all, everyone has very different tastes in music. 00:00:18.370 --> 00:00:19.735 Now, what are the odds 00:00:19.735 --> 00:00:20.921 that your body will need 00:00:20.921 --> 00:00:23.154 the exact same medical care and treatment 00:00:23.154 --> 00:00:24.924 as another person's body? 00:00:24.924 --> 00:00:26.301 Even lower. 00:00:26.301 --> 00:00:27.772 As we go through our lives, 00:00:27.772 --> 00:00:29.763 each of us will have very different needs 00:00:29.763 --> 00:00:31.806 for our own healthcare. 00:00:31.806 --> 00:00:34.439 Scientists and doctors are constantly researching ways 00:00:34.439 --> 00:00:37.005 to make medicine more personalized. 00:00:37.866 --> 00:00:39.031 One way they are doing this 00:00:39.031 --> 00:00:41.644 is by researching stem cells. 00:00:41.644 --> 00:00:45.034 Stem cells are cells that are undifferentiated, 00:00:45.034 --> 00:00:48.560 meaning they do not have a specific job or function. 00:00:48.560 --> 00:00:50.644 While skin cells protect your body, 00:00:50.644 --> 00:00:52.358 muscle cells contract, 00:00:52.358 --> 00:00:54.485 and nerve cells send signals, 00:00:54.485 --> 00:00:58.915 stem cells do not have any specific structures or functions. 00:00:58.915 --> 00:01:00.908 Stem cells do have the potential 00:01:00.908 --> 00:01:04.264 to become all other kinds of cells in your body. 00:01:04.264 --> 00:01:05.842 Your body uses stem cells 00:01:05.842 --> 00:01:08.759 to replace worn-out cells when they die. 00:01:08.759 --> 00:01:11.209 For example, you completely replace 00:01:11.209 --> 00:01:14.556 the lining of your intestines every four days. 00:01:14.556 --> 00:01:16.808 Stem cells beneath the lining of your intestines 00:01:16.808 --> 00:01:19.719 replace these cells as they wear out. 00:01:20.349 --> 00:01:22.971 Scientists hope that stem cells could be used 00:01:22.971 --> 00:01:26.512 to create a very special kind of personalized medicine 00:01:26.512 --> 00:01:29.691 in which we could replace your own body parts with, 00:01:29.691 --> 00:01:32.188 well, your own body parts. 00:01:32.188 --> 00:01:34.628 Stem cell researchers are working hard 00:01:34.628 --> 00:01:36.696 to find ways in which to use stem cells 00:01:36.696 --> 00:01:38.196 to create new tissue 00:01:38.196 --> 00:01:39.572 to replace the parts of organs 00:01:39.572 --> 00:01:43.118 that are damaged by injury or disease. 00:01:43.118 --> 00:01:45.962 Using stem cells to replace damaged bodily tissue 00:01:45.962 --> 00:01:48.675 is called regenerative medicine. 00:01:48.675 --> 00:01:51.907 For example, scientists currently use stem cells 00:01:51.907 --> 00:01:53.799 to treat patients with blood diseases 00:01:53.799 --> 00:01:55.911 such as leukemia. 00:01:55.911 --> 00:01:57.799 Leukemia is a form of cancer 00:01:57.799 --> 00:02:00.051 that affects your bone marrow. 00:02:00.051 --> 00:02:03.109 Bone marrow is the spongy tissue inside your bones 00:02:03.109 --> 00:02:05.383 where your blood cells are created. 00:02:05.383 --> 00:02:08.903 In leukemia, some of the cells inside your bone marrow 00:02:08.903 --> 00:02:12.652 grow uncontrollably, crowding out the healthy stem cells 00:02:12.652 --> 00:02:14.865 that form your blood cells. 00:02:14.865 --> 00:02:16.991 Some leukemia patients can receive 00:02:16.991 --> 00:02:19.069 a stem cell transplant. 00:02:19.069 --> 00:02:20.753 These new stem cells will create 00:02:20.753 --> 00:02:24.041 the blood cells needed by the patient's body. 00:02:24.041 --> 00:02:25.558 There are actually multiple kinds 00:02:25.558 --> 00:02:27.288 of stem cells that scientists can use 00:02:27.288 --> 00:02:29.623 for medical treatments and research. 00:02:29.623 --> 00:02:32.913 Adult stem cells or tissue-specific stem cells 00:02:32.913 --> 00:02:34.710 are found in small numbers 00:02:34.710 --> 00:02:37.046 in most of your body's tissues. 00:02:37.046 --> 00:02:39.180 Tissue-specific stem cells replace 00:02:39.180 --> 00:02:41.180 the existing cells in your organs 00:02:41.180 --> 00:02:43.433 as they wear out and die. 00:02:43.433 --> 00:02:45.676 Embryonic stem cells are created 00:02:45.676 --> 00:02:48.827 from leftover embryos that are willingly donated 00:02:48.827 --> 00:02:51.444 by patients from fertility clinics. 00:02:51.444 --> 00:02:53.867 Unlike tissue-specific stem cells, 00:02:53.867 --> 00:02:57.145 embryonic stem cells are pluripotent. 00:02:57.145 --> 00:02:58.524 This means that they can be grown 00:02:58.524 --> 00:03:01.430 into any kind of tissue in the body. 00:03:02.168 --> 00:03:03.782 A third kind of stem cells 00:03:03.782 --> 00:03:07.240 is called induced pluripotent stem cells. 00:03:07.240 --> 00:03:10.988 These are regular skin, fat, liver, or other cells 00:03:10.988 --> 00:03:12.156 that scientists have changed 00:03:12.156 --> 00:03:15.146 to behave like embryonic stem cells. 00:03:15.146 --> 00:03:17.450 Like embryonic stem cells, 00:03:17.450 --> 00:03:20.401 they, too, can become any kind of cell in the body. 00:03:20.401 --> 00:03:22.409 While scientists and doctors hope to use 00:03:22.409 --> 00:03:24.218 all of these kinds of stem cells 00:03:24.218 --> 00:03:26.825 to create new tissue to heal your body, 00:03:26.825 --> 00:03:28.597 they can also use stem cells 00:03:28.597 --> 00:03:32.134 to help understand how the body works. 00:03:32.134 --> 00:03:34.640 Scientists can watch stem cells develop 00:03:34.640 --> 00:03:36.908 into tissue to understand the mechnanisms 00:03:36.908 --> 00:03:39.941 that the body uses to create new tissue 00:03:39.941 --> 00:03:42.656 in a controlled and regulated way. 00:03:42.656 --> 00:03:44.996 Scientists hope that with more research, 00:03:44.996 --> 00:03:47.329 they can not only develop specialized medicine 00:03:47.329 --> 00:03:49.239 that is specific to your body 00:03:49.239 --> 00:03:51.036 but also better understand 00:03:51.036 --> 00:03:52.294 how your body functions, 00:03:52.294 --> 00:03:53.788 both when it's healthy 00:03:53.788 --> 00:03:55.404 and when it's not.