hey everyone it's nurse Sarah and in this video I'm going to be covering the heart's Anatomy such as the chambers the great vessels and the valves so let's get started the human heart is located in the media stanum which is the cavity between your right and left lung and it's positioned slightly left to the center of the chest and is behind the sternum now when some people try to picture the human heart they think of a heart shape like this so a nice red heart that just sits right there in the chest but in reality it's more shaped like a cone that sets in your chest upside down so the base is on the top and the pointed part is at the bottom and it's sort of sideways in there so that pointed part is known as the Apex and it's going to point more to the left side of the body and the base is the top part and it's going to be like positioned toward the right shoulder in a nursing you want to be familiar with the Bas and the Apex especially the Apex because the Apex is the place where the appical pulse is taken so this is the point of maximum impulse hence the strongest contraction and the reason you want to know where this is is because whenever we give medications like dejin we want to measure that appical pulse beforehand and appical pulse is typically located on the left side of the chest at that fifth intercostal space at the midclavicular line while on the flip side the base of the heart is located more about right behind your sternum at that second inner coal space now let's go inside the heart and look at its structure so here you're going to see an anterior view of the heart and the left and right will be flipped on your view of the screen so just remember that whenever I'm talking about the right side and the left side so the chambers include the following on the right side we have the top chamber which is the right atrium and then right below that we have the right ventricle then over here on the left side we have the left atrium which is the top chamber and then below that we have the left ventricle and all of these Chambers work beautifully together to pump blood from the right side of the heart to the left side of the heart so it goes from the right side over on the right side that blood's always going to be deoxygenated it's going to go up through a great vessel known as the pulmonary artery it's going to hit the lungs get oxygenated now it's going to go back to the left side of the heart through the pulmonary vein and it's going to enter in the left atrium and then it's going to go all the way through the left side and go up through another great vessel known as the aorta and it's going to be pumped throughout the body so let's take it chamber by chamber talk about all those neat structures inside of the heart and we're going to go in the sequence of how blood would really flow through the heart so I'm going to start on the right side here is the right atrium and this is the top chamber that receives deoxygenated blood from the superior vnea inferior vnea and the coronary sinus now the walls that make up the right atrium are thinner compared to the walls that make up the left atrium and the reason for this is because the pressure PR is lower on the right side than the pressure on the left side so this Superior vnea will drain deoxygenated blood into the r Atrium and this blood is going to come from the head the neck and the upper part of the chest and the upper extremities while the inferior vena is also going to drain deoxygenated blood to the right atrium but this blood is going to come from the lower extremities the abdomen and pelvic area and then last but not least is the coronary sinus and it opens into the right atrium and it's going to drain deoxygenated blood from The myocardium and The myocardium remember is the middle layer of the heart and it allows the heart to contract also within this chamber is the fossa ovalis which is found in the wall between the right and left atrium known as the inter atrial septum this is a passage way in the heart of a baby in utero that allows blood to bypass the lungs which are not functioning at this point until birth because remember the placenta is what oxygenates the baby's Blood In Utero therefore for after birth when the baby takes its first breath this area should SE shut leaving only an indentation in the Atria however sometimes this doesn't always happen and this can lead to a payon framan ovali which is known as a PFO and this can lead to the formation of clots which could cause a stroke now let's take a look at the inner surface of the r Atrium and it's interesting because on its anterior inner side it has these comb like ridges known as pectinate muscles and pectinate is Latin for comb and as you can see here we have a heart and it's been like peeled open and look at those pectinate muscles they do look like comb like ridges now these comb like ridges actually have a purpose they're not just there to make the heart look more interesting what they do is they help that right atrium contract blood down into the right ventricle and these muscles are found in an area known as the Oracle of the heart and the oracle is like a pouch like extension that comes off of The Atrium and both the right and left atrium have them now you may be wondering why do they term this Oracle well remember from medical terminology that the term Oracle refers to the outer ear so just use your imagination a little bit and look at these oracles with me notice they sort of look a little bit like two little flappy dog ears just hanging off on the side of each Atrium so not only do they help the Atria control ract blood down into the ventricles a little bit better but they also act as an extra space of storage for blood so if your heart has increased physical activity it can access that extra blood storage up in those little flappy ears and help maintain cardiac output also located near the pectinate muscles in the right atrium is an important Smooth Ridge called the Christa terminalis and here you can see an example of what that looks like this heart again has sort of just been peeled open so you can see it and this plays a vital role in guiding how electrical impulses travel throughout the Atria and from the SA node to the AV node so the heart can contract in a rhythmic way then as we go down through the right atrium and open into the right ventricle we encounter the tricuspid valve the tricuspid valve is lined with endocardium and remember that's the inner layer of the heart and it has three strong cusp or flaps and that's why it's called the tricuspid valve this valve is one of the two atrio ventricular valves in the heart with the other being the mitol also known as the bicuspid valve and these valves connect the Atria and ventricles together hence why we call them atrio ventricular the tricuspid valve allows blood to easily flow from the right atrium to the right ventricle but prevents the back flow of blood from The ventricle to the Atria when the ventricles contract by tightly seiling shut the right ventricle is smaller and has thinner walls compared to the left ventricle and it can have these attributes because it just has to pump deoxygenated blood up through pulmonary circulation which typically has lower pressure whereas the left ventricle has to be larger and thicker wall because it has to pump blood up throughout the whole body and it has to go against a systemic High pressured system now there are important structures on the inner surface of the right ventricle that help it contract the tabuli Carney which carne means meaty are meaty ridges on the inner surface of the ventricle that give The ventricle support so it can contract blood out properly also within this area are papillary muscles and papilla means we're talking about a protruding structure similar to like a nipple or a cone and they connect the truspa valve to the citin Denny which are strong string-like cords that create tension on the trusa valve to keep it closed and they work together with a pap muscles to help prevent collapse of the valve during ventricular contraction and make sure that blood flows in the correct direction and they do this by Contracting when the ventricles contract then right after the right ventricle you will find the pulmonic valve also known as the pulmonary valve and this valve is one of the two semi lunar valves in the heart and the reason we call them semi lunar valves is because they're made up of three cuffs that sort of look like Crescent moons and these semi lunar valves help connect the ventricles to the great vessels and are lined with endocardium which is smooth and these valves are not supported in the same way as atro ventricular valves which use the cend Deni and the papillary muscles but these valves rely on the changes of pressure in the heart for example when the ventricles contract it causes the semi lunar valves to open and blood flows into either the pulmonary artery or the aorta then when the ventricles relax pressure Falls and this causes the valves to shut so blood doesn't go back into the ventricles therefore the pulmonic valve connects the right ventricle and the pulmonary artery while the aortic valve connects the left ventricle and aorta and notice that the name of the semi lunar valve tells you which areas it connects to either ventricle so taking a little bit more of an in-depth look at the pulmonic valve we know that its goal is to really just prevent back flow of blood into that right ventricle so how it does this is It's really dependent on pressure changes within that right ventricle so when the r ventricle goes to contract that increases pressure inside that ventricle and that allows that valve to pop open so once it opens that blood is pushed up through the valve into the pulmonary artery once it leaves that drops the pressure and that droing pressure will allow that valve to close which prevents the back flow of blood into that right ventricle so now that blood has left our right ventricle we are in the pulmonary artery and the pulmonary artery sometimes is referred to as the pulmon Ary trunk now the pulmonary artery is pretty unique because it carries blood away from the heart that is deoxygenated and I know sometimes you may hear this saying that arteries always carry oxygenated blood away from the heart but yes what the pulmonary artery is an exception to that little say because it carries deoxygenated blood away from the heart now this artery starts out as one artery and then it splits into two we have the right and the left and each of those arteries feed into the right and left lung because its whole goal is to get deoxygenated blood to the lung so it can get oxygenated and the walls of the pulmonary artery are actually thinner than the other grape vessel which is found on the other side of the heart known as the aorta and the reason for that is because we want that pulmonary artery to be able to efficiently deliver blood to the lungs without high pressure because if we get high pressure going to the lungs it can damage the lungs over time now after that blood becomes oxygenated by the lungs it will return to the left side of the heart via the pulmonary veins there are four pulmonary veins with two sets coming off each lung and connecting to the left atrium and as with the pulmonary artery the pulmonary veins are unique veins because they carry oxygenated blood back to the heart specifically the left atrium whereas veins you know generally carry deoxygenated blood back to the heart and the left atrium is mainly seen on the posterior side of the heart and is slightly smaller than the Rye Atrium because it has thicker walls these thicker walls are needed because it must contract against the high pressure on this side of the heart the inside surface of the left atrium is more smooth than the right atrium and it has less pectinate muscles within its Oracle oxygenated blood will leave the left atrium and go through the second atrio ventricular valve called the mitol valve which is also known as the bicuspid valve this valve has two cusps lined with endocardium and if you need help remembering where each atrioventricular valve is located think of how the blood flows through the heart by starting on the right side and remember the phrase try before you buy like you know whenever you buy something you want to try it out before you buy it so the tricuspid valve is first and this is on the right side and the bicus valve is second on the left side and as a side note from a nursing standpoint you really want to be familiar with these heart valves particularly whenever we're talking about cases of endocarditis endocarditis can be caused by IV drug use or it can be caused by a severe infection that's got in the blood because remember your blood just flows through these valves and if you have little germs in the blood it'll stick onto these valves as they flow through and I've assisted with transesophageal Echo tees and I have seen patients in their very early 20s who have been using IV drugs and they have had extremely large vegetations on these Valves and they end up having to have heart valve replacement surgery and other procedures done so it's very serious so back to the mitro valve this valve opens to allow blood to flow from the left atrium to the left ventricle and it helps prevent blood from back flowing into that left atrium now just like with the truspa valve this valve is also connected to the cend Denny and the papillary muscles and this is so the valve can be held in place during the contractions of the left ventricle and the left ventricle is a structure that pumps oxygenated blood throughout the body because it gets it into that other great vessel known as the aorta and it is a very important chamber if we have damage to this left ventricle let's say because a patient had a my cardion farction and this ventricle just doesn't want to contract like it should the patient will enter into heart failure so separating the left ventricle from the right ventricle is a wall called the interventricular septum and as I pointed out earlier the left ventricle is much larger and has thicker walls of mardum then the right ventricle and it helps form the apex of the heart so these unique attributes of the left ventricle allows it to just easily pump against the high pressure resistance of the systemic circulation it also contains the tabuli Carney those meaty ridges the papillary muses and the citin Denny on its inner surface which work in a similar manner as we discussed with the right ventricle when blood leaves the left ventricle it passes through the second semi lunar valve called the aortic valve and this valve connects left ventricle and aorta and it works in the same manner as the pulmonary valve in regards to pressure changes based on ventricular contraction and relaxation and after blood passes through the aortic valve it's going to enter into the aorta which is going to go up through the ascending aorta and distribute oxygenated blood throughout a network of arteries that are going to Branch off and one of those important branches is going to be the right and left coronary arteries and these coronary arteries are just want to like wrap around the heart and just feed that myocardium fresh oxygenated blood so that is a walk through of the anatomy of the heart now if you'd like to learn more about that network of branches known as the coronary arteries and the layers of the heart you can access the videos in the link below and thank you so much for watching