Heart Physiology

by Jason Amores Sumpter
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Hi. In this video we'll be looking at the physiology of the heart and examining how the heart pumps blood. No, the heart circulates blood generally by filling up its chambers from the veins and then pushing that blood through the arteries. Now the veins are going to empty into chambers known as atria. These air thinner, less muscular chambers than the ventricles and the ventricles, which are more muscular than the Atria, are going to be the powerful pumping stations that push that blood through the arteries of the body. So, really, the atria are there to receive blood and move it into the ventricles. And the ventricles are the guys who do the rial heavy lifting and actually push that blood into the vasculature. Now the act of pumping by the heart is known as the cardiac cycle. This is a a complete cycle off, pumping out blood and filling up with blood. It's divided into two phases, known as Sistol and Dia stole. Sistol is the contraction phase where the muscles of the heart are going to contract and blood is ultimately gonna be pumped. Dia stole is the relax ation phase, which is going to allow the heart to actually fill with blood. Now me jump out of the image here. And let's talk about what's going on with our atria and our ventricles during these two phases. Now, when the atria and the ventricles are in Dia stole blood is going to flow into those atria and ventricles. So here we are in Di a stall and you can see that blood. This is our superior vena cava. Here's our inferior vena cava. These are Veena ka vie, Right? So from the Vienna Cav, I blood is going to enter into our me actually switch colors here, so it's easier to see on the blue background. This is our right atrium, and this is our right ventricle. So blood is going to flow into these. And on the other side we have our left atrium and left ventricle. And of course, the left atrium is going to be receiving blood from the pulmonary artery. So here we have Veena cover. And here I'm sorry. I said pulmonary artery. I meant pulmonary vain. So these chambers are going to fill up now. The atria are going to experience Sistol before the ventricles do so. The atria are going to be in Sistol, the ventricles in diastolic. And what What this is going to allow for is the blood in the atria to be pushed through those Avie valves, those atrial ventricular valves and fill up the ventricles. Then the Atria are going to go into Dia stole. And, um, the ventricles are going to go into Sistol, and that's gonna push the blood from the ventricles. And you can see this over here. Push the blood from the ventricles into the arteries through those semi lunar Valle's. So this whole process is recorded in electrical signals that look like this, right? If you've ever seen, like, a doctor show or a movie where there's a scene in the hospital, there's always a machine in there that has, like, little green screen or something with this little line going across it. And it's like but but boop that's monitoring the heart rate. So this whole, uh, blip right here, if you want to call it that is actually recording the electrical signals that air going through the heart during heart contractions. So let's actually flip the page and talk about how those electrical signals start and how they propagate