[Music] when new adventures complete what are the answers to never ranging questions in your brain f-zero race to find the reason or the play from he thought went to outer truth of any Ryu science in the real world hi I'm Olivia welcome to real-world science today we'll explore two amazing body systems so get ready for some heart pounding breathtaking action as we explore the circulatory and respiratory systems our bodies are like very complex machines whether we're running jumping swimming or just sleeping our bodies depend on many different systems working together in order to function properly today we'll explore two incredible body systems the circulatory system and the respiratory system first we'll take a look at the respiratory system then we'll discuss the circulatory system and learn how these two systems work together [Music] we need to breathe in order to live we breathe in oxygen that is something that every cell in our body needs breathing is only one part of respiration inhaling and exhaling the average person breathes more than 20,000 times in just one day the second part of respiration is called cellular respiration through cellular respiration our cells combine oxygen with food molecules this produces energy for our bodies and then releases carbon dioxide water your respiratory system consists of the lungs the trachea and the passageways that lead to the lungs like other body movements breathing is controlled by muscles the lungs are surrounded by our ribs which have muscles attached to them at the base of the lungs is a large dome shaped muscle called the diaphragm here's how it works when you inhale the rib muscles and diaphragm contract this lifts the chest wall upward and outward when you exhale or breathe out the rib muscles and diaphragm relaxed making the chest cavity smaller squeezing the air out of the lungs your nose is the primary passageway into and out of the respiratory system the inside of your nostrils are lined with cilia and mucus which trap particles that are found in the air cilia and mucus also warm and moisten the air inside of your nose from there the air moves down into the throat or the pharynx the pharynx is also used as a passageway for food but there's a cleverly placed a little flap of tissue called the epiglottis it prevents food from entering the trachea or windpipe the trachea carries air from the pharynx to the lungs when air reaches the lungs it moves through smaller and smaller passageways called Branka brach you look like upside-down trees at the end of each of the branch of the Brockie our alveoli through the alveoli oxygen passes into the bloodstream and carbon dioxide passes out of the blood and is eventually exhaled this is called the gas exchange the exchange of oxygen and carbon dioxide occurs where the respiratory system meets the circulatory system through the respiratory system you bring oxygen into your body the circulatory system delivers the oxygen and other nutrients to the rest of the body let's see how that works I am sure you've seen a stethoscope before a doctor uses it to hear what's happening inside of your body if you hold the stethoscope to the middle of your chest just listen to what you can hear that's the sound of a beating heart the heart is the strongest muscular organ in your body the heart is the central control for the entire circulatory system by placing two fingers on your wrist you can also feel your circulatory system at work that's called your pulse the circulatory system is also referred to as the cardiovascular system the cardiovascular system consists of the heart all the different blood vessels and blood it carries the substances your body needs to cells in your body then it carries the waste products away let's take a look at each part of the cardiovascular system first blood if you've ever cut yourself or had a nosebleed you've seen what blood looks like but what exactly is blood bud is made up of four components plasma red blood cells white blood cells and platelets blood transports materials to and from all parts of the body most of the materials travel in plasma plasma is the fluid part of the blood if you lad test tube filled with blood sit eventually the blood will separate into layers the yellow liquid at the top is plasma plasma is made up of 90% water the remaining 10% is minerals and nutrients sugars and proteins the red substance resting on the bottom is a mixture of blood cells the red blood cells are the cells of the blood that carry oxygen from the lungs and deliver it to every other cell in your body red blood cells or RBC's are made mostly of iron containing protein called hemoglobin hemoglobin chemically binds with oxygen molecules that caused the celtic bright-red in just one drop of blood there are about five million red blood cells viewed with a very powerful microscope red blood cells look like little disks with their middles pinched in a red blood cell has no nucleus and therefore cannot live long every second about two million red blood cells die it's a good thing for us that our bone marrow produces new red blood cells at the same rate white blood cells are also produced in bone marrow if you were to look at a white blood cell under a microscope it would look something like this in a single drop of blood there are about 80,000 white blood cells white blood cells are the body's disease fighters pathogens are viruses or bacteria these can enter your body and make you sick some way blood cells search for pathogens when they find some they engulf them other white blood cells release antibodies a chemical that helps destroy pathogens as soon as a person starts to bleed platelets begin to come together to form a plug that helps reduce blood loss platelets also release a variety of chemicals that react with proteins to create a chemical called fibrin fibrin leaves a net across the wound in the blood vessel and traps the blood cells eventually a blood clot forms a scab is a dried blood clot on the skin surface people who lose too much blood because of a wound or surgery may need a blood transfusion through a transfusion a person is given blood that has been donated by another person scientists determine blood type by marker molecules on red blood cells your red blood cell molecule markers determine your blood type and the type of blood you can safely receive and transfusions now that we know about blood let's take a look at the heart without the heart the blood wouldn't go anywhere the heart is the strongest muscle on your body it is able to pump blood around your entire body from head all the way down to your toes let me give you an idea of how much blood your heart pumps every day this is one quart of milk your heart pumps the equivalent of five to six thousand quarts of blood every day if we could look inside the heart we would see that it has a left and right side the sides are separated by a thick muscular wall called the septum each side of the heart has an upper chamber called the atrium this is the right atrium this is the left atrium each side has two lower chambers these are called ventricles the right ventricle and the left ventricle the atria and the ventricles are separated by one-way valves here is how blood flows through the heart first when the heart muscle relaxes oxygen-rich blood from the lungs filled the left atrium at the same time the right atrium those with oxygen-poor blood coming back from the body then the heart muscle contracts and blood is squeezed through the valves from the atria into the ventricles when the ventricles contract blood from the right ventricle goes to the lungs to pick up oxygen while blood from the left ventricle goes to supply oxygen to the rest of the body as blood moves through the heart the valve closes preventing blood from going backwards that love dub sound a beating heart makes is caused by the closing of the valves what makes the heart beat is a small group of cells in the right atrium called the pacemaker the pacemaker sends out electrical signals that make the heart muscle contract how does the blood get everywhere in the body the answer is blood vessels blood vessels are like hollow tubes through which blood flows there are three types of blood vessels in your body arteries carry blood away from the heart capillaries are where substances are exchanged between the blood and body cells and veins directs the blood back to the heart all of these work together to supply blood to the body the right ventricle pumps oxygen poor blood into arteries that lead to the lungs while in the capillaries in the lungs blood absorbs oxygen and releases carbon dioxide now the oxygen-rich blood travels through the veins to the left atrium this loop is called the pulmonary circulation the circulation of blood between your heart and lungs the heart pumps oxygen-rich blood from the left ventricle into the arteries and then capillaries as the blood travels through the capillaries it transports oxygen and other nutrients to the body's cells at the same time removing waste material the oxygen poor blood travels back to the heart and is delivered into the right atrium now it's interesting to know that veins don't push blood through the body as much as the force of the arteries do here is a cool experiment you can do to help you remember this all you need to do is take any kind of squeeze bottle like this ketchup and squeeze it as hard as you can with one hand that's like the force the vein uses now squeeze it as hard as you can with two hands that's the amount of force the artery uses when you feel your pulse while you're actually feeling is the pressure your blood is exerting against the walls of your blood vessels that's called blood pressure blood pressure rises and falls with each heartbeat and can be measured using an instrument called the sphygmomanometer blood pressure is expressed in millimeters of mercury and recorded by two numbers the first number is a measure of blood pressure while the ventricles contract and pump blood to the arteries this higher number is called systolic pressure when the ventricles relax the blood pressure Falls the lower pressure is called diastolic pressure the two numbers are expressed as systolic pressure over a diastolic pressure a typical blood pressure reading for a young adult is 120 over well that pretty much covers the respiratory and circulatory systems it is important to understand how your body systems work so you can keep them running smoothly how do you do that well to maintain cardiovascular health you should exercise regularly exercising strengthens your heart muscle and helps to prevent cardiovascular disease eating rate also helps eat a balanced diet with fruits and vegetables and other foods that have nutrients that your body needs stay away from foods high in fat like french fries chips and doughnuts exercising and eating right will help you maintain a healthy respiratory and circulatory system in the real world [Music] you