1 00:00:00,000 --> 00:00:05,280 Good morning, my name is Naomi and I'm going to talk about the human digestive system. 2 00:00:06,519 --> 00:00:08,359 The digestive system. 3 00:00:08,720 --> 00:00:15,980 It takes around 24 hours for our dinners to make its way through the 9-meter-long digestive trough. 4 00:00:16,519 --> 00:00:21,000 On its trip, it's mixed with acids and digestive juices 5 00:00:21,000 --> 00:00:26,219 and squeezed until all the nutrients that the body needs are absorbed. 6 00:00:26,219 --> 00:00:33,219 Then the smelly leftovers along with the innards of the bacteria are ready to exit the body. 7 00:00:34,219 --> 00:00:42,219 We are going to follow our food to learn about the bits of our bodies that make up the human digestive system. 8 00:00:43,219 --> 00:00:51,219 It all starts here. Up to 28 strong teeth chomp our food breaking it into smaller bits. 9 00:00:51,219 --> 00:00:55,219 Meanwhile, the tongue keeps moving the food around. 10 00:00:55,219 --> 00:01:03,219 It also squeezed the chewed grub into swallowable lumps, pushing them back towards the throat. 11 00:01:05,219 --> 00:01:13,219 Here you also find the salivary glands that produce most of the slimy liquid in your mouth. 12 00:01:13,219 --> 00:01:19,219 This saliva moistens food, making it easier to swallow. 13 00:01:19,219 --> 00:01:40,219 The esophagus. This tube contracts to shift chewed food down to your stomach. The squeezing motion of the muscle is called peristalsis and it occurs throughout the digestive system. 14 00:01:40,219 --> 00:01:49,219 Stomach. Next stop in our journey through the human digestive system is stomach. 15 00:01:49,219 --> 00:02:00,219 This stretchy muscular bag is about the size of a tennis ball when it's empty, but expands to the size of a football one to store a massive meal. 16 00:02:00,219 --> 00:02:15,219 As soon as the food plops inside, the stomach lining releases digestive juices and acids that break down the food even more, giving harmful bacteria. 17 00:02:15,219 --> 00:02:28,219 Muscles help in putting the food together with the juices until it becomes a sloppy soup that will fly, that's ready to go into small intestines. 18 00:02:28,219 --> 00:02:36,199 Intestines. Despite the name, the small intestine is really not that small. It's 6.5 meters long. 19 00:02:37,159 --> 00:02:46,500 It's in this tube that all the nutrients in our mushy up food pass through. The small intestine lining and into the blood. 20 00:02:47,300 --> 00:02:52,400 Once all the goodness is gone, the sloppy mixture passes to the next part of the intestines. 21 00:02:52,400 --> 00:03:12,710 More than twice as wide as the small intestine, but only 1.5 meters long, the large intestine's job is to swoop up water, salts, and minerals from the indigestible leftovers. 22 00:03:12,710 --> 00:03:21,710 Finally, the remaining semi-solid waste, called feces, travels to the lower colon and red tongue for storage. 23 00:03:21,710 --> 00:03:29,710 When you go to the toilet, a ring of muscles calls. The anus relaxes to allow the poo out. 24 00:03:29,710 --> 00:03:37,710 A healthy diet, drinking water and plenty of exercise are key to taking good care of your digestive system. 25 00:03:37,710 --> 00:03:40,710 Fantastic!