1 00:00:01,704 --> 00:00:02,962 - [Narrator] Now that we've gone through 2 00:00:02,962 --> 00:00:05,622 the small intestines and mentioned the different 3 00:00:05,622 --> 00:00:09,000 enzymes and components being secreted into it, 4 00:00:09,000 --> 00:00:10,767 it probably helps to figure out 5 00:00:10,767 --> 00:00:13,245 where those enzymes are coming from. 6 00:00:13,245 --> 00:00:17,068 A lot of the secretions that go into the GI tract 7 00:00:17,068 --> 00:00:20,148 come from accessory organs. 8 00:00:20,148 --> 00:00:24,154 One such accessory organ, is the pancreas. 9 00:00:24,154 --> 00:00:27,630 The pancreas is gonna secrete a whole series 10 00:00:27,630 --> 00:00:29,380 of digestive enzymes, 11 00:00:30,222 --> 00:00:32,639 but also sodium bicarbonates. 12 00:00:33,769 --> 00:00:37,779 Now this digestive enzymes can break down carbohydrates. 13 00:00:37,779 --> 00:00:39,226 They can break down some lipids. 14 00:00:39,226 --> 00:00:42,340 They can break down proteins. 15 00:00:42,340 --> 00:00:47,141 The sodium bicarbonate is helping as a buffering. 16 00:00:47,141 --> 00:00:51,093 A buffering which will help take the acidic solution, 17 00:00:51,093 --> 00:00:53,026 which came from the stomach, 18 00:00:53,026 --> 00:00:56,855 and help to buffer it back to more of a neutral solution. 19 00:00:56,855 --> 00:01:01,417 Which is where the small intestines likes to be. 20 00:01:01,417 --> 00:01:04,100 So two of these digestive enzymes are 21 00:01:04,100 --> 00:01:06,183 Trypsin and Chymotrypsin. 22 00:01:07,270 --> 00:01:11,016 Both, Trypsin and Chymotrypsin, are going to work 23 00:01:11,016 --> 00:01:13,183 on breaking down proteins. 24 00:01:14,674 --> 00:01:18,200 That means, in the stomach we had Pepsin, 25 00:01:18,200 --> 00:01:20,900 in the small intestines we're gonna have 26 00:01:20,900 --> 00:01:24,951 Trypsin and Chymotrypsin, which are being secreted 27 00:01:24,951 --> 00:01:26,284 by the pancreas. 28 00:01:28,284 --> 00:01:31,613 We also have pancreatic amylase. 29 00:01:31,613 --> 00:01:34,975 While the pancreatic amylase is helping to break down 30 00:01:34,975 --> 00:01:36,475 our carbohydrates. 31 00:01:38,211 --> 00:01:40,557 And we have Lipase. 32 00:01:40,557 --> 00:01:42,860 While Lipase, it kind of sounds like lipids, 33 00:01:42,860 --> 00:01:45,277 so Lipase breaks down lipids. 34 00:01:46,634 --> 00:01:50,590 So all three of these, proteins, carbohydrates and lipids, 35 00:01:50,590 --> 00:01:54,125 can all be broken down by different enzymes 36 00:01:54,125 --> 00:01:58,368 and all these enzymes are secreted from the pancreas. 37 00:01:58,368 --> 00:02:02,030 One thing to note, each one of these, protein, 38 00:02:02,030 --> 00:02:04,074 carbohydrate, lipid, 39 00:02:04,074 --> 00:02:08,241 each one is broken down by a very specific enzyme. 40 00:02:09,742 --> 00:02:12,409 You can't just take carbohydrates and say 41 00:02:12,409 --> 00:02:14,256 Lipase breaks them down. 42 00:02:14,256 --> 00:02:16,389 It doesn't wort that way. 43 00:02:16,389 --> 00:02:20,556 So each enzyme is specific to what it can break down. 44 00:02:22,990 --> 00:02:26,471 Another accessory organ is gonna be the liver. 45 00:02:26,471 --> 00:02:29,424 The liver can produce bile. 46 00:02:29,424 --> 00:02:31,674 Now, bile is not an enzyme. 47 00:02:33,074 --> 00:02:35,825 Bile's called an emulsifier. 48 00:02:35,825 --> 00:02:37,575 It emulsifies lipids. 49 00:02:38,579 --> 00:02:41,079 So, what emulsify actually is, 50 00:02:42,083 --> 00:02:46,632 is it take lipid molecules and pull them apart. 51 00:02:46,632 --> 00:02:49,099 So you still have lipids 52 00:02:49,099 --> 00:02:51,555 but instead of one big chunk of lipid 53 00:02:51,555 --> 00:02:55,265 it's broken into many smaller pieces of lipids. 54 00:02:55,265 --> 00:02:59,432 So by separating it, you've increased the surface area. 55 00:03:01,888 --> 00:03:04,247 The liver also deals with the system called 56 00:03:04,247 --> 00:03:07,137 the hepatic portal system. 57 00:03:07,137 --> 00:03:09,919 Now, the hepatic portal system 58 00:03:09,919 --> 00:03:13,989 is going to take all the blood from the digestive tract 59 00:03:13,989 --> 00:03:16,947 and shuttle it into the liver. 60 00:03:16,947 --> 00:03:21,203 Well, why do you think you'd want to collect all the blood 61 00:03:21,203 --> 00:03:23,085 from the digestive tract? 62 00:03:23,085 --> 00:03:25,874 I mean, you have the arteries that bring the blood in. 63 00:03:25,874 --> 00:03:28,396 Gives the nutrients and gases to the different parts 64 00:03:28,396 --> 00:03:30,256 of the GI tract. 65 00:03:30,256 --> 00:03:31,616 And then you have the veins, 66 00:03:31,616 --> 00:03:35,709 which are a part of a hepatic portal system. 67 00:03:35,709 --> 00:03:39,699 The veins are gonna collect all that blood, 68 00:03:39,699 --> 00:03:43,325 bring it all from the GI tract, back to the liver. 69 00:03:43,325 --> 00:03:44,158 So, why? 70 00:03:46,302 --> 00:03:49,461 Well, think about what you eat and what you ingest. 71 00:03:49,461 --> 00:03:52,753 Is the food you eat liquidy drink, sterile, 72 00:03:52,753 --> 00:03:54,430 totally clean? 73 00:03:54,430 --> 00:03:57,966 Not a single thing in it they don't want? 74 00:03:57,966 --> 00:04:00,234 Unfortunately not. 75 00:04:00,234 --> 00:04:01,709 You're gonna have bacteria, 76 00:04:01,709 --> 00:04:04,753 you're gonna have little particles, you're gonna debris. 77 00:04:04,753 --> 00:04:06,811 Well, all these things, 78 00:04:06,811 --> 00:04:09,322 that are being ingested, 79 00:04:09,322 --> 00:04:13,116 they're being sometimes absorbed through the walls 80 00:04:13,116 --> 00:04:15,181 of the intestines. 81 00:04:15,181 --> 00:04:18,566 That means they're entering your blood stream. 82 00:04:18,566 --> 00:04:21,820 What can happen is, the hepatic portal system 83 00:04:21,820 --> 00:04:24,210 can help filter and clean out 84 00:04:24,210 --> 00:04:28,593 those particles and things that shouldn't be there. 85 00:04:28,593 --> 00:04:32,154 But, on a better note, the hepatic portal system 86 00:04:32,154 --> 00:04:36,321 also helps to sort nutrients and store some nutrients. 87 00:04:39,790 --> 00:04:42,461 Look just usually below the liver, 88 00:04:42,461 --> 00:04:46,540 make it look toward the front, you'll find the gallbladder. 89 00:04:46,540 --> 00:04:51,215 The gallbladder is going to take the bile from the liver, 90 00:04:51,215 --> 00:04:54,715 it's going to concentrate it and store it. 91 00:04:56,209 --> 00:04:58,414 So the liver produces bile, 92 00:04:58,414 --> 00:05:00,844 which then goes down to the gallbladder, 93 00:05:00,844 --> 00:05:04,561 the gallbladder concentrates it, pulls the water out, 94 00:05:04,561 --> 00:05:07,978 and then stores the bile until necessary. 95 00:05:09,007 --> 00:05:13,174 That necessary is when the body needs to break down lipids. 96 00:05:15,447 --> 00:05:17,379 So if you've ingested lipids, 97 00:05:17,379 --> 00:05:21,309 your body will cheer the gallbladder to release. 98 00:05:21,309 --> 00:05:22,284 But if you're thinking, well, 99 00:05:22,284 --> 00:05:23,623 what happens to the person 100 00:05:23,623 --> 00:05:25,702 that had to go through gallbladder surgery? 101 00:05:25,702 --> 00:05:28,202 Had their gallbladder removed. 102 00:05:29,199 --> 00:05:33,618 Well in that case, the liver still produces bile. 103 00:05:33,618 --> 00:05:36,641 The difference is though, the bile goes straight 104 00:05:36,641 --> 00:05:39,470 into the small intestines. 105 00:05:39,470 --> 00:05:42,759 There's no storage and concentration. 106 00:05:42,759 --> 00:05:45,802 So the individuals that are without a gallbladder 107 00:05:45,802 --> 00:05:48,807 a lot of times have to kind of keep an eye their diets. 108 00:05:48,807 --> 00:05:52,219 Watch how much lipid they're ingesting. 109 00:05:52,219 --> 00:05:55,104 Because their body can only handle so much at a time. 110 00:05:55,104 --> 00:05:59,271 Because there's only so much bile available at a time. 111 00:06:00,487 --> 00:06:02,357 In this diagram you can see the liver, 112 00:06:02,357 --> 00:06:04,012 that huge thing taking up almost 113 00:06:04,012 --> 00:06:07,354 a good third of the screen there if not more. 114 00:06:07,354 --> 00:06:09,983 Then just below the liver, come off to your left, 115 00:06:09,983 --> 00:06:13,328 you can see the gallbladder in green. 116 00:06:13,328 --> 00:06:16,363 The gallbladder is connected into the liver. 117 00:06:16,363 --> 00:06:18,418 But both the liver and gallbladder then, 118 00:06:18,418 --> 00:06:21,377 are connected down through the pancreas, 119 00:06:21,377 --> 00:06:23,507 that yellow thing, the pancreas, 120 00:06:23,507 --> 00:06:26,386 into the small intestines. 121 00:06:26,386 --> 00:06:29,550 Specifically, the duodenum or duodenum. 122 00:06:29,550 --> 00:06:32,682 Again, pronunciation either or. 123 00:06:32,682 --> 00:06:34,756 So all this different pancreatic juice, 124 00:06:34,756 --> 00:06:36,438 all these different enzymes, 125 00:06:36,438 --> 00:06:39,174 all these different chemical substances, 126 00:06:39,174 --> 00:06:41,674 are coming in to the duodenum. 127 00:06:44,458 --> 00:06:47,131 Well, once you finally get through that small intestines, 128 00:06:47,131 --> 00:06:50,069 you end up in the large intestines. 129 00:06:50,069 --> 00:06:52,420 Now, the large intestines can also 130 00:06:52,420 --> 00:06:55,196 absorb nutrients and water. 131 00:06:55,196 --> 00:06:59,541 But not nearly as much as the small intestines. 132 00:06:59,541 --> 00:07:01,378 The small intestines really is 133 00:07:01,378 --> 00:07:04,015 where the majority of it occurs. 134 00:07:04,015 --> 00:07:06,086 So what's the large intestines doing? 135 00:07:06,086 --> 00:07:08,963 Well, it's temporarily storing waste. 136 00:07:08,963 --> 00:07:13,569 It'll escort waste if your body is ready for elimination. 137 00:07:13,569 --> 00:07:17,736 And then it'll eliminate all the solid waste at one point. 138 00:07:19,275 --> 00:07:22,445 So we're looking at this large intestines here. 139 00:07:22,445 --> 00:07:24,378 You can see the small intestines 140 00:07:24,378 --> 00:07:27,301 is leading into the large intestines. 141 00:07:27,301 --> 00:07:31,051 It past the valve called the Ileocecal valve. 142 00:07:32,008 --> 00:07:36,175 Well, this valve has a main purpose of back flow prevention. 143 00:07:37,262 --> 00:07:41,686 Because, what's inside of the large intestines? 144 00:07:41,686 --> 00:07:45,565 What's in the large intestines is all the waste. 145 00:07:45,565 --> 00:07:46,690 And you really don't want that waste 146 00:07:46,690 --> 00:07:49,273 going back up into your system. 147 00:07:50,383 --> 00:07:52,345 Well here's that appendix again, 148 00:07:52,345 --> 00:07:53,990 really no digestive function, 149 00:07:53,990 --> 00:07:57,107 but it's all sitting down there so. 150 00:07:57,107 --> 00:07:57,940 The cecum. 151 00:07:58,790 --> 00:08:01,750 The cecum is the start of a large intestines. 152 00:08:01,750 --> 00:08:05,623 It's where all the broken down particles 153 00:08:05,623 --> 00:08:08,641 and waste product, leaves the small intestines 154 00:08:08,641 --> 00:08:10,944 and enters the large intestine. 155 00:08:10,944 --> 00:08:13,702 The area's called the cecum. 156 00:08:13,702 --> 00:08:15,965 You head up the ascending, 157 00:08:15,965 --> 00:08:18,548 across the transverse colon, 158 00:08:18,548 --> 00:08:20,631 down the descending colon 159 00:08:21,531 --> 00:08:23,448 into the sigmoid colon. 160 00:08:24,488 --> 00:08:28,678 Eventually, you're storing in the rectum. 161 00:08:28,678 --> 00:08:31,093 Once enough has been stored in the rectum 162 00:08:31,093 --> 00:08:34,540 and potentially pushing up into the sigmoid colon there. 163 00:08:34,540 --> 00:08:38,518 Once enough is stored, the body is going to release it. 164 00:08:38,518 --> 00:08:41,281 So it's going to release it through defecation. 165 00:08:41,281 --> 00:08:43,698 Right through the anal canal. 166 00:08:47,118 --> 00:08:51,035 Now, on the anal canal, which ends at the anus, 167 00:08:51,960 --> 00:08:54,657 you can see there's an internal and external 168 00:08:54,657 --> 00:08:56,913 sphincter muscles. 169 00:08:56,913 --> 00:08:59,591 So you have two different and very distinct 170 00:08:59,591 --> 00:09:02,258 sets of muscles around the anus. 171 00:09:03,728 --> 00:09:05,890 These muscles are meant to control 172 00:09:05,890 --> 00:09:08,158 either the defecation process, 173 00:09:08,158 --> 00:09:10,435 allowing the defecation to occur. 174 00:09:10,435 --> 00:09:13,088 Or, control the defecation process 175 00:09:13,088 --> 00:09:16,088 by not allowing defecation to occur. 176 00:09:17,108 --> 00:09:20,411 So the internal, smooth muscle, 177 00:09:20,411 --> 00:09:22,171 your body controls it. 178 00:09:22,171 --> 00:09:23,359 It says what it wants to 179 00:09:23,359 --> 00:09:25,776 and when it doesn't want to open up. 180 00:09:25,776 --> 00:09:29,068 You have absolutely no choice over it. 181 00:09:29,068 --> 00:09:33,550 The external anal sphincter, which is skeletal muscle, 182 00:09:33,550 --> 00:09:37,413 that's the one you have conscious control over. 183 00:09:37,413 --> 00:09:40,185 So that's the muscles that needs to either be 184 00:09:40,185 --> 00:09:44,352 closed or opened by a conscious action of your thoughts.