1 00:00:00,620 --> 00:00:05,419 Nutrition is the function that we need to get energy for the body. 2 00:00:06,219 --> 00:00:08,220 You can get that energy from food. 3 00:00:09,039 --> 00:00:11,580 Having a varied diet helps you to be healthy. 4 00:00:12,259 --> 00:00:20,399 The vitamins and nutrients from food are processed by your digestive system and absorbed by your circulatory system. 5 00:00:21,019 --> 00:00:24,839 What you don't need is expelled by the excretory system. 6 00:00:25,519 --> 00:00:28,699 Here are the main parts of the digestive system. 7 00:00:28,699 --> 00:00:57,359 The nose, mouth, salivary glands, esophagus, stomach, pancreas, liver, small intestine, large intestine, rectum, and the anus. 8 00:00:57,359 --> 00:01:05,269 There are five steps to digestion. The first starts with the nose and the mouth. 9 00:01:06,150 --> 00:01:15,230 The second with the esophagus. The third with the stomach. The fourth, the small intestine. 10 00:01:16,069 --> 00:01:24,980 And finally, the fifth, the large intestine. In the first step of digestion, the sense of smell 11 00:01:24,980 --> 00:01:31,140 triggers the production of saliva in your salivary glands. You can see here that the 12 00:01:31,140 --> 00:01:38,640 salivary glands are connected to your nasal cavity. Then the saliva helps your teeth to 13 00:01:38,640 --> 00:01:47,469 crush food before we chew it. In the mouth, the tongue makes a ball with the food. This ball is 14 00:01:47,469 --> 00:01:55,290 called the bullous. We then swallow the bullous through the esophagus. The esophagus is a stretchy 15 00:01:55,290 --> 00:02:01,230 tube that connects the back of the throat with the stomach. The muscles of the esophagus squeeze 16 00:02:01,230 --> 00:02:09,909 the food down to the stomach. The stomach breaks down the food using its strong muscular wall 17 00:02:09,909 --> 00:02:17,370 and gastric juices. The gastric juices mix with the bolus to kill dangerous bacteria. 18 00:02:18,310 --> 00:02:27,270 When food leaves the stomach, it has been transformed into a liquid. The liquid food 19 00:02:27,270 --> 00:02:35,009 arrives to the small intestine and mixes with bile and the pancreatic juices. There, proteins, 20 00:02:35,389 --> 00:02:43,409 carbohydrates, vitamins, minerals, and fats are separated. The nutrients pass through the wall 21 00:02:43,409 --> 00:02:51,590 of the small intestine and they are absorbed into the blood. The waste, which is what the body does 22 00:02:51,590 --> 00:02:59,389 not need, passes to the large intestine. There, water is absorbed into the blood and the solid 23 00:02:59,389 --> 00:03:08,650 waste leaves the body through the rectum and the anus. The circulatory system delivers blood 24 00:03:08,650 --> 00:03:15,349 through blood vessels to different tissues in the body. At the center of your circulatory system 25 00:03:15,349 --> 00:03:23,490 is the heart. The heart is a powerful organ that beats every second. It beats faster when we do 26 00:03:23,490 --> 00:03:31,830 exercise because our body needs more oxygen. It is made by a special type of muscle that never 27 00:03:31,830 --> 00:03:39,650 gets tired. We can find four chambers in the heart. The top two chambers are called the right 28 00:03:39,650 --> 00:03:46,770 in the left atrium and the bottom ones are called the right and left ventricles. They are separated 29 00:03:46,770 --> 00:03:53,969 by valves which prevent blood from flowing backwards. The heart sends oxygen and nutrient 30 00:03:53,969 --> 00:04:02,229 rich blood to the body. Here we can see the different parts of the heart. Here is the superior 31 00:04:02,229 --> 00:04:18,259 vena cava, the aorta, the pulmonary artery, the right atrium, the left atrium, the 32 00:04:18,259 --> 00:04:30,649 right ventricle, the left ventricle, and the inferior vena cava. Inside of your 33 00:04:30,649 --> 00:04:37,670 circulatory system is blood. Blood is a warm mixture of liquid and cells. The 34 00:04:37,670 --> 00:04:40,750 The different cells carry oxygen and fight germs. 35 00:04:41,730 --> 00:04:46,110 The liquid carries nutrients to body cells and takes away waste. 36 00:04:47,189 --> 00:04:50,790 Your blood flows in your blood vessels every second of the day. 37 00:04:51,449 --> 00:04:55,250 It can flow quick in arteries and slower in your veins. 38 00:04:56,870 --> 00:04:59,889 Let's take a closer look inside of a blood cell. 39 00:05:00,170 --> 00:05:05,589 If we were to look at it underneath a microscope, we would be able to see the different parts. 40 00:05:06,509 --> 00:05:09,250 There are three different types of blood vessels. 41 00:05:10,430 --> 00:05:14,009 There are arteries, veins, and capillaries. 42 00:05:15,269 --> 00:05:22,470 Inside of these blood vessels, there is plasma, which is a yellow liquid that carries nutrients and waste products. 43 00:05:23,629 --> 00:05:28,009 The red blood cells carry oxygen and carbon dioxide. 44 00:05:29,350 --> 00:05:34,689 The white blood cells surround and absorb germs to fight infection. 45 00:05:36,959 --> 00:05:44,000 The platelets are what joins together to stop bleeding when we're losing blood because of a cut. 46 00:05:46,839 --> 00:05:49,740 Let's talk about the three different types of blood vessels. 47 00:05:50,379 --> 00:05:57,120 The arteries carry oxygenated blood from the heart to the rest of the body. 48 00:05:58,079 --> 00:06:04,720 The veins carry blood that contain carbon dioxide back to the heart. 49 00:06:04,720 --> 00:06:09,500 And the capillaries are the tiniest blood vessels. 50 00:06:10,399 --> 00:06:13,220 They connect the arteries and the veins. 51 00:06:14,139 --> 00:06:17,579 Gases and nutrients can pass through their thin walls. 52 00:06:19,120 --> 00:06:20,720 How does circulation work? 53 00:06:21,379 --> 00:06:25,279 The first step is the deoxygenated blood from your body 54 00:06:25,279 --> 00:06:30,759 passes from the right atrium to the right ventricle inside of your heart. 55 00:06:31,660 --> 00:06:35,879 Then it leaves the heart through the pulmonary artery to go to the lungs. 56 00:06:37,120 --> 00:06:45,160 The second step, blood releases carbon dioxide and takes oxygen in through the lungs when we breathe. 57 00:06:45,759 --> 00:06:49,199 And then it returns to the heart through the pulmonary veins. 58 00:06:52,639 --> 00:07:00,300 Next, the oxygenated blood flows to the left atrium and the left ventricle in the heart 59 00:07:00,300 --> 00:07:03,720 to be pumped to the rest of the body through the aorta. 60 00:07:04,920 --> 00:07:08,319 The aorta is the biggest artery in the body. 61 00:07:11,420 --> 00:07:17,379 The aorta carries blood to small arteries and then to capillaries throughout the body. 62 00:07:17,379 --> 00:07:25,420 It is in the capillaries where blood exchanges with oxygen and nutrients to carbon dioxide and 63 00:07:25,420 --> 00:07:35,160 waste. The deoxygenated blood passes from capillaries to veins and finally to the superior 64 00:07:35,160 --> 00:07:46,110 vena cava and the inferior vena cava. Blood is carried by these veins to the heart where the 65 00:07:46,110 --> 00:07:59,040 process starts again. Let's review the steps of circulation. The first step, the deoxygenated blood 66 00:07:59,040 --> 00:08:05,800 passes from the right atrium to the right ventricle. It leaves the heart through the 67 00:08:05,800 --> 00:08:15,360 pulmonary artery to go to the lungs. Second step, blood releases carbon dioxide and takes oxygen 68 00:08:15,360 --> 00:08:21,319 in the lungs. Then it returns to the heart through the pulmonary veins. 69 00:08:23,199 --> 00:08:31,639 Third, the oxygenated blood flows to the left atrium and the left ventricle to be pumped to 70 00:08:31,639 --> 00:08:39,460 the rest of the body through the aorta. The aorta is the biggest artery in the body. 71 00:08:39,460 --> 00:08:49,179 Fourth step, the aorta carries blood to small arteries and then to capillaries. 72 00:08:50,000 --> 00:08:59,019 It is in the capillaries where blood exchanges oxygen and nutrients to carbon dioxide and waste. 73 00:08:59,019 --> 00:09:10,539 Fifth, the deoxygenated blood passes from capillaries to veins and finally to the superior 74 00:09:10,539 --> 00:09:19,419 vena cava and the inferior vena cava. Blood is carried by these veins to the heart where the 75 00:09:19,419 --> 00:09:29,870 process starts again. The respiratory system. The cells in our body cannot survive without oxygen. 76 00:09:30,529 --> 00:09:38,230 During the process of respiration, oxygen is combined with nutrients to produce energy. 77 00:09:38,230 --> 00:09:45,129 In that process, our cells produce carbon dioxide that is expelled from the body. 78 00:09:45,129 --> 00:10:06,379 The main parts of the respiratory system are the trachea, the bronchus, the lungs, the diaphragm, bronchioles, alveoli. 79 00:10:10,210 --> 00:10:13,990 The trachea carries air in and out when you breathe. 80 00:10:15,690 --> 00:10:19,809 The bronchus branches from your trachea into your lungs. 81 00:10:19,809 --> 00:10:26,509 The bronchioles are smaller branches from your bronchus. 82 00:10:27,850 --> 00:10:35,309 The alveoli carry out the exchange of gases of carbon dioxide and oxygen. 83 00:10:35,929 --> 00:10:40,240 Let's talk about the steps of respiration. 84 00:10:41,340 --> 00:10:45,000 The first step, air enters through the nose and the mouth. 85 00:10:46,440 --> 00:10:52,379 Second, air passes down through the larynx and then to the trachea. 86 00:10:56,299 --> 00:11:03,179 Third, the bronchus are subdivided into bronchioles to connect the trachea to the lungs. 87 00:11:07,039 --> 00:11:14,860 Fourth, at the end of each bronchiole, we find the alveoli, where the exchange of gas takes place. 88 00:11:15,340 --> 00:11:21,899 Here, oxygen passes from the alveoli and lungs to capillaries into the blood. 89 00:11:24,159 --> 00:11:29,039 At that time, carbon dioxide leaves blood and enters the alveoli. 90 00:11:29,960 --> 00:11:34,259 The air goes through the bronchioles and bronchus to the trachea. 91 00:11:34,980 --> 00:11:37,960 It finally leaves the body through the mouth and the nose. 92 00:11:40,279 --> 00:11:41,799 What happens when we breathe? 93 00:11:42,320 --> 00:11:45,379 Let's talk about inhalation and exhalation. 94 00:11:46,259 --> 00:11:52,639 When we take a breath, our diaphragm contracts and allows the lungs to inflate. 95 00:11:53,299 --> 00:11:56,539 The ribs expand to make more room for the air. 96 00:11:59,700 --> 00:12:00,299 Exhalation. 97 00:12:00,299 --> 00:12:06,659 When we breathe out or exhale, our ribs relax and move back. 98 00:12:07,860 --> 00:12:16,200 The diaphragm relaxes, pushing carbon dioxide out of the lungs through the trachea, nose, and the mouth. 99 00:12:18,840 --> 00:12:25,879 The excretory system excretes waste from the body. 100 00:12:26,220 --> 00:12:31,480 Our body excretes carbon dioxide, urine, and water. 101 00:12:32,179 --> 00:12:37,820 This system is made up by urinary system and the sweat glands. 102 00:12:38,840 --> 00:12:42,820 So here's the urinary system, and here are the sweat glands. 103 00:12:44,340 --> 00:12:49,080 The urinary system helps us get rid of waste from the blood. 104 00:12:49,080 --> 00:12:55,500 It produces and expels 1.4 liters of urine each day. 105 00:12:58,279 --> 00:13:01,019 We also eliminate water through the skin. 106 00:13:01,019 --> 00:13:06,759 The sweat glands help us to cool down by excreting sweat 107 00:13:06,759 --> 00:13:10,240 Sweat is a mixture of water and minerals 108 00:13:10,240 --> 00:13:13,000 It leaves the body through our pores 109 00:13:13,000 --> 00:13:18,250 Here are the renal arteries 110 00:13:18,250 --> 00:13:21,070 They carry blood to the kidneys 111 00:13:21,070 --> 00:13:24,330 The kidneys 112 00:13:24,330 --> 00:13:28,370 They clean your blood and filter your waste 113 00:13:28,370 --> 00:13:31,450 Your readers 114 00:13:31,450 --> 00:13:35,529 They carry urine from kidneys to the bladder 115 00:13:35,529 --> 00:13:42,899 The bladder stores urine and releases it when it's convenient. 116 00:13:45,440 --> 00:13:49,519 Your urethra, it helps the bladder to be emptied.