1 00:00:04,910 --> 00:00:07,629 How do our bodies create electricity? 2 00:00:07,629 --> 00:00:09,550 The short answer is chemical energy. 3 00:00:09,550 --> 00:00:12,470 To understand why, let's look at the long answer. 4 00:00:12,470 --> 00:00:16,809 What most people think of as electricity is simply the movement of an electrical charge. 5 00:00:16,809 --> 00:00:21,570 To move, and as a result use, the potential charge, we need an energy source. 6 00:00:21,570 --> 00:00:25,750 Some of the most common are hydroelectric, nuclear, solar, and wind. 7 00:00:25,750 --> 00:00:29,690 Technological advances have allowed us to harness these sources, giving us wonders like 8 00:00:29,690 --> 00:00:32,329 computers and vibrating smartphones. 9 00:00:32,329 --> 00:00:37,210 The energy created by chemicals is due to the reactions of the atoms and molecules present. 10 00:00:37,210 --> 00:00:41,850 All of the elements we take in our bodies, like oxygen, sodium, potassium, and calcium, 11 00:00:41,850 --> 00:00:46,329 have a specific electrical charge, meaning they have a specific number of electrons, 12 00:00:46,329 --> 00:00:47,850 protons, and neutrons. 13 00:00:47,850 --> 00:00:52,570 Those specific charges, whether positive or negative, react to the charges of adjacent 14 00:00:52,570 --> 00:00:53,570 molecules. 15 00:00:53,570 --> 00:00:57,810 This reaction is what creates the energy needed to create electricity. 16 00:00:57,810 --> 00:01:02,210 When we eat or drink, the large molecules within our food get broken down by digestion, 17 00:01:02,210 --> 00:01:03,869 creating similar molecules. 18 00:01:03,869 --> 00:01:07,090 Those smaller molecules can be used by our cells to do work. 19 00:01:07,090 --> 00:01:09,989 This process is called cellular respiration. 20 00:01:09,989 --> 00:01:13,829 All of those molecules and elements in our bodies have the potential to create electrical 21 00:01:13,829 --> 00:01:14,829 impulses. 22 00:01:14,829 --> 00:01:19,870 Arguably, the most commonly mentioned electrical current within our bodies is the heart rhythm. 23 00:01:19,870 --> 00:01:25,049 Hearts contain, within them, a grouping of cells known as your sinoatrial node, or SA 24 00:01:25,049 --> 00:01:26,049 node. 25 00:01:26,049 --> 00:01:29,810 These cells within the SA node, sometimes called the pacemaker of the heart, contain 26 00:01:29,810 --> 00:01:33,170 electrolytes both inside and outside of the cells. 27 00:01:33,170 --> 00:01:37,950 The most common electrolytes within the body are sodium, potassium, calcium, magnesium, 28 00:01:37,950 --> 00:01:40,209 phosphorus and chloride. 29 00:01:40,209 --> 00:01:44,489 Sodium and calcium generally reside outside of the SA node cells. 30 00:01:44,489 --> 00:01:46,430 Potassium generally lies within them. 31 00:01:46,430 --> 00:01:49,950 The cell membrane acts as a barrier between these electrolytes. 32 00:01:49,950 --> 00:01:53,909 Pressure within the bloodstream allows sodium to enter the cell, causing potassium to leave 33 00:01:53,909 --> 00:01:54,909 it. 34 00:01:54,909 --> 00:01:57,969 Less potassium leaves the cell than sodium entering it. 35 00:01:57,969 --> 00:02:01,230 The result is a continually growing positive charge. 36 00:02:01,230 --> 00:02:05,849 When the charge reaches a certain point, calcium channels in the cell membrane open up and 37 00:02:05,849 --> 00:02:07,849 allow for calcium to enter. 38 00:02:07,849 --> 00:02:12,710 This makes the interior of the cell extremely positive compared to the outside of the cell, 39 00:02:12,710 --> 00:02:15,069 known as an action potential. 40 00:02:15,069 --> 00:02:19,289 Once that potential reaches a certain point, it has enough power to discharge down the 41 00:02:19,289 --> 00:02:20,729 nerves of the heart. 42 00:02:20,729 --> 00:02:25,930 This electricity causes the muscles to contract and your heart to beat. 43 00:02:25,930 --> 00:02:30,590 Just crossing cell membranes, creating electrical discharges, is one of the countless ways the 44 00:02:30,590 --> 00:02:35,430 body uses the food we eat to create energy and power to do work. 45 00:02:35,430 --> 00:02:41,949 This is why the food content we eat is classified in calories, a calorie being a unit of energy. 46 00:02:41,949 --> 00:02:46,990 As technology advances, medical science will continue to unravel all the mysteries surrounding 47 00:02:46,990 --> 00:02:52,250 how the chemical reactions within our bodies maintain our daily lives and create our own 48 00:02:52,250 --> 00:02:53,150 bioelectricity.