all right, hi everyone, welcome to the first part of the chapter 20 lecture on the heart, the last lectures focused on chapter 19 with the blood, and now we're going to be talking about the muscular pump that drives the blood through the entire body, which is of course the heart, no need to remember these exact numbers I just think they're pretty mind-blowing, that your heart beats about a hundred thousand times per day, every day, for your entire life, which is pretty incredible, and about 8,000 liters of blood moves through your heart every day if you remember, we have about 4 to 6 liters of blood in our whole body, so our entire blood volume is circulating through the heart many many times per day, so, pretty incredible... all right, so let's start by talking about how the heart is really two pumps in one, there is a right side of the heart and there is a left side of the heart, the right side of the heart is all about driving blood out to the pulmonary circuit, pulmonary means lungs, so blood that's in the right atrium up here will then travel down to the right ventricle, when the right ventricle squeezes, it pumps the blood out through the pulmonary trunk and the pulmonary arteries to the lungs, notice that the color of the blood on the right side of the heart is blue, blue represents oxygen-poor blood, the reason why you're sending the blood to the lungs, of course, is to get oxygen, so once the blood has been oxygenated in the lungs, it's going to come back to the left side of the heart, into the left atrium, the left atrium then sends blood down to the left ventricle, and the left ventricle, when it squeezes, pumps blood out the aorta, heading out to all the other tissues in the body, this is called the systemic circuit, so think of the systemic tissues or the systemic circuit as being everywhere in the body except the heart and lungs, and of course the pulmonary circuit is referring specifically to just blood that's traveling between the heart and lungs... now, color, again, blue means oxygen-poor, red means oxygen-rich, so notice how most of the arteries that are shown in the body here are systemic arteries, so they're shown as red, most of the veins are systemic veins, so they're shown as blue, but the pulmonary circuit is the opposite, pulmonary arteries are usually shown as blue or purple pulmonary veins are shown as red, because remember, it's not about color with the definition of an artery versus a vein, it's about direction of flow, see how the pulmonary veins are shown in red because they're carrying blood back to the heart even though it's oxygen-rich, and the pulmonary arteries are shown in bluish purple here because they're showing blood being carried away from the heart even though it's oxygen-poor, so again mostly red vessels, sorry, mostly red vessels that you see on a diagram like this will be arteries, but pulmonary arteries will be blue or purple, and mostly when you see blue vessels on a diagram like this they will be veins, but pulmonary veins are the opposite... all right, the heart is located in between your lungs, behind the sternum, in a space called the mediastinum, if you recall the mediastinum, (the) mediastinum is the space between the lungs in the thoracic cavity, the heart sits a little bit to the left of midline, about two-thirds to the left of your midline, about 1/3 to the right of your midline, for that reason the left lung is a little bit smaller than the right lung, because you have to accommodate for the heart being a little bit shifted to the left, the heart is between the sternum and the esophagus there in the mediastinum... if we were to look at what contains the heart in the mediastinum, it's a sac called the pericardium, breaking that down, ium is tissue, card, heart, peri, surrounding or around, so the tissue that surrounds the heart, the outermost part of the pericardium is the fibrous pericardium or pericardial sac, it's this dense fibrous connective tissue, very strong and leathery, that kind of forms the outer protective layer of this pericardium, it's also the tissue that anchors the heart to the underlying diaphragm that sits below the heart there... just inside the fibrous pericardium, or the pericardial sac, will be the serous pericardium, now, if you remember from back in the fall, serous means watery, and a serous membrane is always going to have two layers to it, if I take you back to the fall with chapter 4, when we were learning about the different tissue membranes, we talked about how serous membranes are usually these simple squamous type of membranes that, again, produce a watery, serous, lubricating fluid, they have two parts to them, there's a deeper visceral part, and a slightly more superficial parietal part, and in between those two parts will be a space that will contain a lubricating, watery fluid, so the pericardium is one example of a serous membrane, and that's what we see here in chapter 20, so the outer layer of the serous pericardium is the parietal layer, the parietal layer, there you can see the little simple squamous running along the inside of the fibrous part, and then there's a space in between, called the pericardial cavity, that contains pericardial fluid, which is just, again, lubricating, watery-type, serous fluid, and then the visceral layer of the pericardium is what's on the outside of the heart, so the innermost layer of the pericardium is really the same layer as the outermost layer of the heart wall, as we will see on the next slide... so we take a closer look, we see the pericardium here, and here is the innermost layer of the pericardium, which is the visceral layer, and notice that's really the same as the outermost layer of the entire heart wall so again, visceral layer of the pericardium and epicardium are the same thing, it just depends on your framework, your context... the myocardium is by far the thickest layer of the heart wall, it consists of a bunch of cardiac muscle tissue, if you remember, cardiac muscle tissue has a bunch of cells that are connected by intercalated discs and gap junctions, so ions can flow from cell to cell, which means action potentials, you know, electrical impulses, can flow from cell to cell, this will be important for allowing the heart to contract in a smooth, rhythmic way, as we will see a little bit later, so myo means muscle myocardium is the tissue of the heart that is muscle, and again, the function of it is to contract and squeeze the chambers of the heart to force blood out and move blood through the system, and then the innermost layer of the heart wall is the endocardium, remember endo means inside or within, so it's going to be a nice simple squamous endothelium that provides a smooth surface so that as blood cells are bumping by, there's minimal friction, similar to how the inner lining of blood vessels, called the tunica intima, is also a nice, smooth simple squamous type of endothelium as well... all right, so in terms of the anatomy of the heart, we are really focusing on that in lab, so as long as you know the anatomy of the heart well from the lab learning guides, you would be fine for any heart anatomy question that I would ask on a lecture exam, so I may ask a few heart anatomy based questions on the first lecture exam, but again, it'll be redundant with what you're learning in lab, so make sure to really get this stuff down in lab, and you would be fine for any questions I would ask on the lecture exam about heart anatomy... so some things we can see here, we can see the outer parts of the four chambers, the atria are the upper chambers of the heart, so we see part of the left atrium and the right atrium, we see the lower chambers of the heart, the right ventricle and then the left ventricle here over on the other side, this bottom part of the heart is called the apex, the point, of the heart, and then up here is called the base of the heart, and that is going to be where all the major blood vessels move in and out, so we can see looking at the posterior view, again, you can see all four chambers, you can see some of the major vessels as well, so definitely focus on that when you get into your lab learning... so here's a view, a sectional view, through the heart, so this is as if you were gonna take a blade and just cut through the heart in a coronal, or frontal, section, so same thing as before, make sure to learn this anatomy well in lab, and then if I ask you any questions about it on a lecture test, you'll be ready to go... I would also like you to know just the basic flow through the heart, which we'll talk more about in the next few slides, but as you can see, the blue arrows are representing oxygen-poor blood, the red arrows are representing oxygen-rich blood, you know, blood in the right side of the heart never mixes with blood in the left side of the heart, and so, again, we will talk more about, kind of, what to know here in terms of where blood flows from one place to another... here is a schematic view of the heart, and this is meant to be just a simplified line drawing to show you pretty much the same thing that was on this figure, I do like this picture, it's pretty detailed, it shows you how the thickness of the left ventricular wall is is thicker than the thickness of the right ventricular wall, that's because the right ventricle, if you remember, pumps blood out through the pulmonary circuit, the lungs, which are right next door, that's easy, whereas the left ventricle pumps its blood out into the systemic circuit, which is everywhere else in the body from head-to-toe, fighting gravity and the whole nine yards, so the left ventricle has to have a much thicker, thicker wall we can see here the valves are all represented, SLV stands for semilunar valve, we just call this the pulmonary valve for short same thing here, we call this the aortic valve, but here it's shown as the aortic SLV, or semilunar valve, the AV valves are shown with the chordae tendineae, the heart strings, anchored to papillary muscles, so again, it's a fairly accurate representation of the heart, so if this helps you learn heart anatomy please use it... so we're gonna go chamber by chamber through the heart, and talk about how the blood flows through, let's start with the right atrium, again, the atria are the receiving chambers of the heart, so the right atrium receives oxygen-poor blood from three sources, from parts of your body in the systemic circuit that are above the chest level, so that's going to include your head, your neck, your upper limbs, your arms, oxygen-poor blood from those areas are going to come in through the superior vena cava, and vena cava just means great vein, so these are very large veins, if you're coming from systemic tissues from below chest level, so the rest of your trunk, your legs you're gonna come up through the inferior vena cava into the right atrium and then the coronary sinus is actually coming from the coronary circulation which we will talk more about later, you can see the opening of the coronary sinus right there, that's going to be oxygen-poor blood that's actually coming from the heart wall itself, so that'll make more sense when we cover the coronary circulation a little bit later... you're going to see little bumpy ridges inside the wall of the atria, those are called pectinate muscles, you can't really see them very well in this picture, you'll be able to see them better on the, in the models in lab, there's actually more pectinate muscles than shown here, they're just on the inside of the anterior part of the right atrial wall, same thing with the left atrium, there are pectinate muscles in there, they're just not visible in this view because they're shown better on the anterior part of the atrial wall, which is cut away, and not shown... there's a shallow depression, and a shallow depression is a fossa, and it's oval shaped, so it's called the fossa ovalis, in a fetal heart this was actually a hole called the foramen ovale, because if you think about it, a fetus doesn't really need a pulmonary circuit to be that important, you know, if you have oxygen-poor blood that's coming in to the right atrium, there's really no need to send that blood out to the pulmonary circuit, to the lungs, to get oxygen because in a fetus, the the lungs aren't working yet, so instead, in a fetus there's a hole here, and the blood that's in the right atrium can directly pass into the left atrium, it's hard to see from this picture, but the two atria share a common wall called the interatrial septum, it's just located in the back, so blood that can be in the right atrium can flow through the foramen ovale into the left atrium, and then it can just get on its way through the systemic circuit, it's just a bit of a bypass in the fetus, but once you're born and your lungs start working, this is now a liability, you do not want your oxygen-poor blood to intermingle with the oxygen-rich blood on the left side so this will seal up, it usually seals up within about three months after birth and then it's just the fossa ovalis at that point, in some instances it won't seal up naturally, so a minor procedure will need to be done to go in and actually fix that and make sure it's all sealed up... all right, so blood travels from the right atrium down through the right AV valve, the right AV valve, or right atrioventricular valve, here, is also known as the tricuspid valve because it has three flaps, which you will be able to see better a little bit later, AV valves are anchored in place by chordae tendineae which just means tendinous cords, these are your heartstrings, and then those are anchored to the ventricular walls by papillary muscles, papilla means little bump, so these bumps of muscle that have the chordae tendineae attached are papillary muscles, a lot of students think that the papillary muscles and the chordae tendineae are what actually open and close the valves, and that is a mistaken viewpoint, in reality, valves open and shut based on pressure changes within the heart, but the papillary muscle will contract and put tension on the chordae tendineae to basically anchor the AV valves during ventricular contraction, to make sure they don't evert, or prolapse, which is, go the wrong way back into the atrium, so they're basically just trying to stabilize the valves and keep them from flopping back backwards into the atrium... trabeculae carneae this means beams of flesh, so you see all these, like, different, I guess, ridges that are in the ventricles, the ridges that don't have the chordae tendineae attached are called trabeculae carneae, and then, again, the bumps of muscle that do have the chordae tendineae attached are papillary muscles and then the little ridges in atria are pectinate muscles, so kind of three different terms for the muscles that you will find inside the heart... there's a special little ridge here called the moderator band, it's going to have an electric function that we will discuss more later in this lecture... all right, so when the right ventricle squeezes, it forces the right AV valve shut, the papillary muscles and chordae tendineae keep the right AV valve from prolapsing into the right atrium, so since this is shut here, the only place for blood to go is to force its way through the pulmonary valve at the base of the pulmonary trunk, up through the pulmonary trunk, which then branches, and you have branches that go to the left and branches that go to the right, those are the pulmonary arteries that are taking this oxygen-poor blood to the lungs, so when it comes to blood flow, you know, I may ask a question or two on the lecture exam, I may say, hey, you're a drop of blood in the right ventricle, what's the next valve you would normally go through, which would be the pulmonary valve, or I might say you're a drop of blood in the pulmonary trunk, or a pulmonary artery, what's the next major structure that you will encounter, and that would be the lungs, because again, pulmonary means you're taking to the lungs, and artery means carrying blood away from the heart, so these are the types of questions, kind of higher-level questions, I'll sprinkle in a couple of them in the first lecture exam, that's what I mean about kind of just knowing the general flow of blood through the heart with these arrows... okay, so once the blood has been oxygenated in the lungs, it's going to return to the heart, to the left atrium, through pulmonary veins, we see a couple pulmonary veins coming from the left lung, the ones coming from the right lung are actually hidden right here, so this oxygen-rich blood comes in to the left atrium, the left atrium contracts to squeeze it down through the left AV valve into the left ventricle, the left atrioventricular valve is also known as the bicuspid valve because it has two flaps, which I'll show you better in a minute, it's also known as the mitral valve, a miter is a Catholic bishop's hat, and you know me, I'm a word nerd, I gotta look up stuff like this, so when I put in miter hat in Google image search, this is what I got, notice how you have a couple different flaps here on the hat, so somebody a long time ago probably Catholic, an early anatomist, looked at that valve and said, hey, that kind of looks like the hat that's on a Catholic bishop or the pope, let's call it the mitral valve, because the hat is called a miter... all right, so once the blood has gone through the mitral valve and is now in the left ventricle, we will notice that the left ventricle, like I mentioned before, has a much thicker myocardium than the right ventricle does, and we explained why earlier, the right ventricle has to only squeeze with enough force to get blood to and from the lungs, whereas the left ventricle has to squeeze with enough force to deliver blood all throughout the entire rest of the body, the systemic circuit, also, notice it's saying (the) left ventricle is right here, this is more accurately the outer wall of the left ventricle, what that line is actually pointing at is the myocardium of the heart wall, so make sure that you realize that when a line is going to the myocardium, if we were to ask, name the layer of the heart wall, myocardium would be the best answer, whereas if we were to say, for example, right here in the middle, what's this structure, the interventricular septum, so hopefully that makes sense, please let me know if you have questions about that... all right, and then, finally, the left ventricle squeezes with a lot of force, and it forces blood up through, you can barely see a little bit of it right there, the aortic valve, into the aorta, and the aorta is the largest artery in the body, it's the main systemic artery, all other systemic arteries branch off of it, so these branches are going to go to your head and neck and arms, and then it's going to curl around to the back of the heart and actually end up going down to feed the rest of your trunk and your legs, notice, it's kind of interesting, the left ventricle, the exit point kind of crosses behind towards the right, and the right ventricle, the exit point crosses in front to the left, so they do this kind of cross, where the pulmonary trunk crosses anterior to the aorta, it's kind of an interesting arrangement... all right so that's the basics of the anatomy of the heart chambers, and what you're gonna find in there, and how blood is going to flow through the heart... here's what a real heart looks like from a cadaver, so I'm not going to spend a lot of time on this here in the lecture, but these images are in the lab learning guide for the gross anatomy of the heart, so you're going to be learning what these structures really do look like in a real heart... here's just another way to look at the difference in the thicknesses of the walls of the left ventricle versus the right ventricle, notice, again, the right ventricle has a much thinner outer wall, and the left ventricle has a much thicker outer wall and it's not about volume, they're both pumping the same amount of blood with each heartbeat, it's about force, it's about pressure, so by being much thicker, you can squeeze harder, and drive the blood out through the systemic circuit, which takes more force than the right side pumping blood through the pulmonary circuit... here's a different look at the valves, and all the valves really work in a similar way in that they function to prevent blood from going backwards from where it came, you want all of the flow through the heart to be a one-way street, you never want blood to flow back where it came from, so for example, if you have blood up here in the left atrium, you want it to be able to flow from the left atrium to the left ventricle, but you want that valve to be able to close to prevent the blood from going backwards, back into the left atrium, so this is kind of how it works, when the left ventricle is relaxed, blood is just flowing freely from the left atrium down through the left AV valve into the left ventricle, but when the left ventricle squeezes and contracts the pressure in here rises, that forces the blood into these little flaps of the left AV valve, it forces them shut, the papillary muscles and the chordae tendineae anchor and hold, to prevent the valve flaps from prolapsing or everting back into the left atrium, the blood only has one place to go, and that's to force its way through the aortic valve into the aorta now, when the ventricle starts to relax again, it's gonna start sucking the blood back, as the blood starts to get sucked back, that forces the flaps of the aortic valve to push together and it closes the valve, so now the blood can't go back into the left ventricle once it's left, so that's the basic mechanics of how the heart valves work, if you have this bird's-eye view, you can see maybe why these valves here are called semilunar valves, somebody thought that these little flaps look like little half moons, also, when we look at this bottom picture we see how the tricuspid valve truly has three cusps, or flaps, and the bicuspid, or mitral, valve has two cusps, or flaps... all right, so next up, coronary circulation one of the true ironies of the heart is that all the blood that's actually flowing through the chambers of the heart is not nourishing the myocardium of the heart itself, the blood that goes to the heart wall itself is through the coronary circulation, we see some coronary arteries in red here coming off the base of the aorta, we see some coronary veins, which are sometimes called cardiac veins, as well, all the coronary veins send their blood to the coronary sinus, which then dumps its blood into the right, the right atrium here, as we discussed before, so it's a bit of a weakness that you have these tiny, these relatively tiny vessels that provide the circulation to the myocardium, which is what drives the heart's function, now, as it says in the yellow box, you're learning coronary arteries and veins in general, in lab you're also learning the coronary sinus specifically in lab, so as long as you know the coronary circulation to that pretty basic level, you'd be able to ask any coronary circulation question I would, you'd be able to answer any coronary circulation question that I would ask in the lecture exam, as well what happens if this goes wrong, well, here on the left, this is an angiogram of a healthy coronary circulation, notice that the vessels are pretty wide open, on the right here, this is a form of heart disease, this is coronary artery disease it's when cholesterol plaques build up in your coronary arteries, and they narrow, and so the myocardium is not getting as much blood as it needs to here, and if one of these coronary arteries gets completely blocked, that's a heart attack, that's a myocardial infarction, so this is a big deal heart disease, it's one of the biggest killers of Americans every single year all right, that is a wrap on the anatomy of the heart, I want to go a little bit further in today's lecture, talk a little bit about some cardiac physiology specifically the electric flow through the heart, so that is done through the cardiac conducting system, these are cardiac muscle cells, (but) their main job is not necessarily to contract, their main job is to just send action potentials efficiently through the heart, you can see over here in purple, the SA node, the AV node, all these other little kind of purple pathways, that makes up your cardiac conducting system, and as it says in this bullet point here, they are really good at conducting electrical impulses, action potentials, more so than a typical cardiac muscle cell would be, so it's just a very efficient way to have electrical flow through the heart this system, everything you see in purple here, is said to be autorhythmic, or automatic, it can set its own rhythm, it's automatically, just spontaneously depolarizing all the time, it all starts up here at the sinoatrial or SA node, we'll talk more about it on the next slide, it's also known as the pacemaker of the heart, this is what actually automatically just every, you know, second or so, it's generating its own action potentials, and then those action potentials are spreading through the rest of the system, so it's important to realize, you do not need your brain or some hormones to cause your heart to beat, it will beat automatically, it sets its own rhythm, you do need neural or hormonal stimulation to change the heart rate, to either slow it down or speed it up, but again, it'll automatically set its own baseline heart rate... and before I go any further, notice these green bars that I added to the drawing here, representing the fibrous cardiac skeleton, and also kind of where the valves are, the AV valves, the electricity does not really flow very well through those parts of the heart, the connective tissue is not very conductive to electrical flow, and the reason I mention that is because the electricity will flow freely through the atria first, but then it won't automatically just go right to the ventricles like this it's blocked here by the connective tissue of the valves and the cardiac skeleton, the only place that the electrical flow can really go through is here at the AV bundle, so that will make more sense in a few minutes when we talk about the overall flow, so I just wanted to kind of point that out now... okay, let's start with the pacemaker, again, the official term is sinoatrial node, or SA node, but it's also just known as the cardiac pacemaker because it sets the pace, of all these different parts of the cardiac conducting system, it has the fastest rate of spontaneous depolarization, it's usually in the 60 to 100 depolarizations per minute range, so that means, again, every second or so, you automatically, or it automatically, generates its own action potential, now if you might remember, normally, if you had an action potential, you get back down to the resting potential down here, you would have to stimulate the muscle cell or the neuron again, to depolarize it back to threshold, to get a new action potential, but it's all automatic with the pacemaker, it's called the pacemaker potential, or prepotential, and it's because the pacemaker cells are already very very leaky to sodium, they already have a lot of sodium channels open, so as soon as the previous action potential finishes, sodium just starts leaking right back in again, whenever positive ions enter, it's becoming more positive, it's depolarizing back to threshold, and automatically generating the next one, and then the next one, and so forth for every single heartbeat, now you may be saying, hey Tony, my resting heart rate is never above 60 or 70, does that mean that my pacemaker doesn't have a hundred beats a minute for its spontaneous rate, not necessarily, yours might naturally be 100 per minute, but when you're at rest, your brain is sending parasympathetic stimulation to the heart, usually via cranial nerve X, the vagus nerve, to slow it down, so even if you naturally had a pacemaker that was more towards the higher end of this range, your resting heart rate would probably still be lower than that, thanks to the brain saying, all right, just slow down a little bit, slow down, let's keep it around 60 or 70... okay, so once the action potential is generated at the SA node, it's gonna spread through the atria first, and again I know you can't see it well in this picture, but the right atrium is actually connected to the left atrium in the back at the interatrial septum, so the signal will be sent through both atria first, remember that there is insulative material here that's preventing it from going directly down to the ventricles, so the next place the signal will go is the AV node, and that's where we'll pick up on the next slide, so the AV node is a little bit slower and more inefficient than the SA node was, and so the signal slows down a little bit as it comes through, you get about a hundred millisecond delay, now that's not a lot that's only a tenth of a second, but having that delay there, that's enough time to finish the atria, the atria depolarizing, and allows the atria to begin, and hopefully finish, their contraction before the ventricles contract, this will be super important in the second part of this lecture that'll be coming early next week, when we talk about the cardiac cycle, how it's very important that the atria get a chance to finish their contraction before the ventricles begin their contractions, so that little 100 millisecond delay by the AV node is very helpful for that... all right, so here we have the AV bundle, also known as the bundle of His, it's not the bundle of his there's no bundle of hers, it's a capital H because that was named after somebody named His, bundle of His, and again, the AV bundle is the only way to basically electrically connect the atria with the ventricles, so as the signal goes down the AV bundle, it branches, it splits, so those are left and right bundle branches, and then the moderator band is a bit of a shortcut, so off of the right bundle branch, the moderator band connects over to some of the papillary muscles in the right ventricle, you want the papillary muscles to begin tensing just right before the entire ventricle contracts, to kind of get ready, because the right ventricular wall is thinner than the left ventricular wall, it's a little bit of a slower signal out to those papillary muscles, if you didn't have this shortcut, so again, the function of the moderator band is just to be a little bit of an electrical shortcut on the right side, to the papillary muscles in the right ventricle, we don't really need that over here on the left side, because since the left side is thicker, the flow of electrical signals through the left side is much faster, so you're able to still get those left papillary muscles tensed right on time and what finishes out the pathway here are the Purkinje fibers, Purkinje fibers also named after a person, Purkinje, very very fast conducting speeds, and so you just accelerate the signal up the outer sides of the ventricles, that way you're really squeezing from the bottom of the heart up, remember, the right ventricle needs to squeeze upwards to put its blood up into the pulmonary trunk, and the left ventricle needs to squeeze upwards to force its blood up into the aorta, so to finish things out for this lecture let's just kind of put a wrap on this flow, you do not need to memorize all these steps, or memorize how many milliseconds each step takes, but you should know the general sequence of the flow here, so let's review, it all starts up here with the SA node, the pacemaker, up here in the right atrium, it spontaneously generates its own action potentials, those action potentials then spread through the walls of both the right atrium and the left atrium, from cell-to-cell, remember how the myocardium has intercalated discs with gap junctions, so it's just a nice smooth flow of electrical signals through the atria first, then remember, it will not go directly down to the ventricles, it'll hit the AV node first, and the AV node gives you that little tenth of a second delay, and then sends the signal down through the AV bundle, the bundle of His on to the bundle branches, the bundle branches that are traveling through the interventricular septum, you've got the little shortcut that branches off on the right, that's the moderator band, and then finally, you reach the apex of the heart and then the Purkinje fibers take over, and they really accelerate the speed of the signal up the outer walls of the ventricles, and that's going to force the ventricles to contract from the bottom up, forcing the blood upward, from the right side through the pulmonary trunk, and from the left side out through the aorta, because of course the AV valves will be shut and reinforced at that point... okay, that is a great stopping point for this particular lecture hopefully you've been jotting down any questions, things that aren't making sense, remember to check with your book, your book is going to be explaining this stuff as well, but anything that's still not making sense after that, make sure you either email me your questions, or hop on to a Zoom session to ask me live all right, have a good day, and I will see you next time