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Current time:0:00Total duration:4:49

Video transcript

so a creature means something is not developed or underdeveloped so we talked about tricuspid atresia we're referring to the fact that the tricuspid valve does not develop and it's not there so usually if we have our normal heart here the oxygenated blue blood comes from the body like that goes into from the right atrium to the right ventricle through the tricuspid valve so remember it's on the right side and his three leaflets if that's why it's tricuspid so blood goes through here from the right ventricle it gets pumped to the pulmonary artery which goes to the lungs so in tricuspid atresia I'm going to erase this whole thing here because the tricuspid valve actually does not develop instead of an opening there and a valve to prevent backflow we just have solid tissue here it's literally just blocked off before we worry about what happens to the blood here let's look at the right ventricle since this is something that happens when the baby's still in the uterus the first thing that happens is our right ventricle also does not develop it's kind of like you don't use it you lose it so since it doesn't get to pump blood there's nothing in here the muscle doesn't develop and our right ventricle is just a tiny little sac it's not functional and therefore there's no blood going to the lungs either I'm just going to block off this whole area it doesn't work all right now we got a big problem because there's no blood come going to the lungs and that is why first let me draw I was forget to draw the atrial septum here because it's like that this is the atrial septum separates the left and right atrium therefore in tricuspid atresia we need a few septal defects for this child to survive so we have an atrial septal defect or we just call it ASD this way when the blood the blue blood comes into the right atrium since you can't go this way into the ventricle it has somewhere to go and in fact it flows through this ASD into the left atrium the left atrium also receives oxygenated blood coming back from the lungs now you might say wait a minute you just said there's no blood flow to the lungs there is but and we'll see you in a second but for right now remember that blue blood coming from the right side through the ASD into the left atrium red blood coming from the lungs here and then we have a mixture of purple blood in the left atrium so the valve here on the left side is fine this is the mitral valve or the bicuspid has two leaflets so this purple blood flows through here into the left ventricle and from there you can go into the aorta so if purple blood going into the aorta to the body it's not good red blood but at least we get some out there get some oxygen out there and now we have to come back to how did the blood get to the lungs in the first place and that's where we have our second septal defect this is our ventricular ventricular septal defect or VSD and of course this one happens between the left and right ventricle so this mixture of purple blood aside from going to the aorta it also comes through here and into our pulmonary artery since the right ventricle is out of commission a left ventricle does the job for the right side and pushes blood purple blood into here as well and from there it goes to the lungs we use green for the branches of lungs from there picks up oxygen and comes back here to the left atrium so this is how our cycle works by taking this right ventricle out of the game we have a hole here to allow the left ventricle to push some blood to the lungs and we have a hole above here in the ASD area so that blood can get to the left side of the heart to begin with at any time you see purple blood going into the aorta this child will be signed on it because that just means the Austrian content of blood we're giving to the body is not very high now the lungs don't care if it receives propyl blood because all it does is give it more oxygen so we actually have a higher oxygen content in the blood going to the lungs but what makes us cyanotic is the fact that purple blood instead of red blood is going out to the body through the aorta so there you have it tricuspid atresia no tricuspid valve meaning no right ventricle