 This video will cover the following objective identify and describe the major anatomical areas of the heart chambers valves and greater vessels This illustration shows an anterior view of the heart blood flows through veins into the Superior chambers of the heart called the atria We'll start by focusing in here on the right atrium The right atrium receives deoxygenated blood blood that has a low oxygen Concentration that is coming from the systemic circuit So this blood has delivered oxygen to cells in tissues all throughout the body And this blood drains through the veins Into the right atrium And so the inferior vena cava is draining deoxygenated blood from the lower regions of the body So the lower limbs as well as the abdominal pelvic cavity are draining blood in through the inferior vena cava Whereas the upper regions of the body the head and the upper limbs are draining blood in through the superior vena cava blood also drains from the Coronary circuit the the blood vessels that are supplying blood to the muscle of the heart wall are the coronary Blood vessels there are coronary arteries that deliver the oxygen rich blood to the heart muscle And then cardiac veins drain that blood So the cardiac veins Like this great cardiac vein or this small cardiac vein Will also drain blood into the right atrium. They will join together So the cardiac veins drain into one large Cardiac vein known as the coronary sinus and then the coronary sinus drains into the right atrium Blood from the right atrium then moves down into the right ventricle the right ventricle Receives the deoxygenated blood from the right atrium and then it pumps this blood out Into the artery known as the pulmonary trunk So the pulmonary trunk then branches into the left pulmonary artery and the right pulmonary artery The left pulmonary artery is carrying this blood To the left lung Whereas the right pulmonary artery carries this blood to the right lung Then inside of the lungs There are small blood vessels known as the pulmonary capillaries where gas exchange occurs Oxygen will diffuse into the gas at the pulmonary capillaries Then the blood from the pulmonary capillaries Is oxygenated blood So notice I switched from the blue ink to the red ink to represent oxygenated blood We commonly illustrate the oxygenated blood in blue and oxygenated blood In red so this oxygenated blood is coming from the lungs And it's going to flow into the left atrium It will flow into the left atrium Through the pulmonary veins so we can see here the left pulmonary veins are draining the blood coming from the left lung and The right pulmonary veins are draining the blood coming from the right lung But both the left and the right pulmonary veins drain into the left atrium and then left atrium Pumps this blood down Into the left ventricle Then the left ventricle pumps blood out into the aorta So here we can see the ascending aorta as part of this large artery the largest artery of the Systemic circuit the aorta Distributes this oxygenated rich blood To smaller arteries that branch all throughout the body This illustration shows us a posterior view of the heart We can see the blood vessels are attached here at the superior region. This is the Base of the heart and down here this pointed region The apex of the heart is pointing off Inferiorly into the left side Now with the posterior view we can see the coronary sinus Which drains the deoxygenated blood from the coronary circuit Back into the right atrium So the inferior vena cava the superior vena cava and the coronary sinus Are the veins that return deoxygenated blood to the right atrium Blood flows from the right atrium down into the right ventricle And then from the right ventricle out into the pulmonary trunk that branches into the Right pulmonary artery and left pulmonary artery carrying the deoxygenated blood to the lungs where It becomes oxygenated then this oxygen rich blood flows back from the lungs through the pulmonary veins Into the left atrium And the left atrium then pumps the blood down into the left ventricle And blood flows from the left ventricle out into the aorta So the aorta is a large elastic artery that can stretch as it receives high pressure blood coming from the left ventricle And then the aorta will branch to numerous smaller blood vessels that distribute oxygen rich blood throughout the body So some more details of the surface anatomy of the heart that we can see in this illustration are the the oracles of the atria So the oracle of the left atrium is shown here the the oracle is a flap like outer portion of the atria That allows the atria to expand in order to hold more blood. So there's a little flap like Exterior portion of each atrium that Slightly resembles the External ear the oracle or pinna of the external ear and that's where this name came from this this flap shape here Looks a little bit like the ear And similarly on the left side this flap shape resembled the external ear And so it's called the oracle of the atrium So another thing we can see on the surface anatomy is the adipose tissue as well as the large arteries and veins are found within these grooves on the surface And so the grooves on the surface of the heart are known as the They're called a sulcus so this is a A sulcus on the surface of the heart and this sulcus is on the posterior in between the left and right Ventricles so we call this the posterior Interventricular sulcus There's also an anterior interventricular sulcus And then a coronary sulcus so the coronary sulcus is Where we see the coronary sinus is located this groove that's running In between the atria and the ventricles That contains the coronary sinus It's called the coronary sulcus And because it is separating the atria from the ventricles it is also sometimes referred to as the atrioventricular groove or atrioventricular sulcus So the coronary sulcus or atrioventricular sulcus are synonyms and they contain the large Cardiac vein known as the coronary sinus the coronary sinus functions to drain Deoxygenated blood coming back from the heart into the Right atrium of the heart There is a groove on the anterior of the heart here Located in between the left and right ventricles This groove is known as the anterior Interventricular sulcus So the anterior interventricular sulcus Is a groove on the anterior of the heart In between the left and the right ventricles and it contains The great cardiac vein as well as the anterior Interventricular artery Another structure from the surface anatomy. I wanted to point out on the anterior view here is the ligamentum arteriosome so ligamentum arteriosome Is connecting between the pulmonary trunk and the arch of the aorta And this is a remnant from a structure known as the ductus arteriosus In the fetal circulation the ductus arteriosus was a A blood vessel or a shunt a vascular shunt a blood vessel that allowed blood to bypass the pulmonary circuit and so In the fetal circulation the lungs are not functioning for gas exchange and the ductus arteriosus would allow blood to be Shunted from the pulmonary trunk into the aorta to bypass The lungs and go directly into the systemic circuit to travel to tissues throughout the body Here we see a view of the internal anatomy of the heart on this illustration from graze anatomy And we can see there are muscular ridges on the inner surface of the heart Within the atria these muscular ridges are called pectinate muscles And so I'll highlight the pectinate muscles in yellow to make those stand out. These are these muscular ridges Of the walls of the atria and so we can only see the pectinate muscles of The right atrium at the moment, but there's also pectinate Muscles that are muscular ridges on the inner surface of the left atrium Now there's also muscular ridges on the inner surface of the ventricles some of these ridges are called tribeculi carnii And there are others that are called papillary muscles So I will use the green color here to highlight the tribeculi carnii So these muscular ridges in here these muscular ridges within the ventricles and you can see they're sort of branching and irregularly arranged And all throughout the wall of the ventricle. There are these tribeculi carnii So the tribeculi refers to the irregularly arranged shape of these ridges and carnii refers to meat and so these are muscular ridges irregularly arranged muscular ridges the Inner surface of the ventricles called tribeculi carnii Now there are also ridges known as papillary muscles that are found in the ventricles and so the papillary muscles Look somewhat similar to the tribeculi carnii however they're attached to heart valves So I'm highlighting papillary muscles with the purple color now And so these papillary muscles they connect through tenderness cords we call the cordy tendony these cordy are what will distinguish the papillary muscles from the tribeculi carnii so cordy tendine like cords that are attaching from the papillary muscles to valves in the heart known as av valves or atrio ventricular valves So the atrio ventricular valves function to prevent blood from flowing backwards from the ventricles into the atria So I'm highlighting the av valves now in purple so av valves av stands for atrio ventricular and there's two av valves the right av valve is the tricuspid valve which prevents blood from flowing backward from the right ventricle into the right atrium whereas the left av valve is labeled bicuspid valve in this illustration however the there's another name for the bicuspid valve This is commonly referred to as the mitral valve So a mitre is the type of hat that the bishops and popes wear the pointed hat So that's where this name came from the mitral valve that has two flaps or cusps has the appearance of the mitre that the hat which is worn by the pope And so that's where its name comes from the mitral valve Also known as the bicuspid valve is the left av valve that prevents blood from flowing backwards from the left ventricle into the left atrium So when the ventricles contract the pressure of blood inside of the ventricles forces the av valves closed And blood is forced out of the ventricles into the arteries there are also Valves that prevent blood from flowing backwards into the ventricles from the arteries when the ventricles relax These are what we call the semilunar valves So semilunar valves we commonly just abbreviate sl So sl valve for semilunar valves Here's the aortic semilunar valve So the aortic semilunar Valve functions to prevent blood from flowing backward out of the aorta into the left ventricle As the left ventricle relaxes and there's a lower pressure in the left ventricle than there is in the aorta the blood in the aorta pushes back on the flaps of the aortic valve causing that those flaps to be pushed closed those flaps have a crescent shape like The moon so semilunar comes from that shape of the crescent similar to the shape of the moon and there's three of those crescent shaped flaps that Push closed in order to prevent backward flow from the aorta into the left ventricle Similarly, there's a pulmonary semilunar valve to prevent backward flow from The pulmonary trunk into the right ventricle, but we cannot see the pulmonary semilunar valve in this view With this illustration of the internal structures of the heart we can see the pulmonary semilunar valve This pulmonary semilunar valve functions to prevent blood from flowing backwards out of the pulmonary trunk into the right ventricle Another structure we can see here is the interventricular septum so the interventricular septum Is this muscular wall Separating the right and the left ventricles another structure we see here is Fossa ovalis Fossa ovalis literally means oval shaped depression in the surface of the right atrium, so this is an an oval shaped indentation In the right atrium But it's a remnant from a structure known as the foramen ovale And foramen ovale is a structure present in the fetal heart that allows blood to flow directly from the right atrium into the left atrium This is important in the fetal circulation because The fetal heart is bypassing the pulmonary circuit shunting blood directly into the systemic circuit as the lungs in the fetal body don't function to Support gas exchange. There's no need to send large amounts of blood through the pulmonary circuit and The foramen ovale would allow this blood to bypass from the right atrium directly into the left atrium normally the Foramen ovale seals at birth to become the fossa ovalis, although it is possible to have a patent foramen ovale A foramen ovale that is allowing blood to move from the right atrium into the left atrium after birth will make the heart Pump less efficiently and can increase the risk for blood clotting Here we have an internal view The picture of the internal structures of the heart where we can see the papillary muscles and the trabecular carnae the ridges of the muscular surface in the ventricles While they have a Similar appearance we can see that the papillary muscles are a little bit more prominent and also attached to the Cordy tendony the tendinous cords that are connecting the av valves to the papillary muscles When the ventricle contracts the papillary muscles also stimulated to contract placing tension on the cordy tendony Which helps to reinforce the av valve preventing Regurgitation preventing the valve from being forced backwards and preventing blood from Being able to move from the ventricle into the atrium