Source: Video and Images Created by Amanda Soderlind
Welcome to this lesson today on the pulmonary and systemic circuits. In this lesson today we will be examining blood as it flows through both of these circuits. So the pulmonary and systemic circuit are two circuits of blood flow.
And in our heart we have four different chambers. Our heart is divided into two halves and each half is divided into two chambers. So each half of our heart pumps blood in a different circuit.
The right side of our heart pumps blood in the pulmonary circuit. And the left side of our heart pumps blood throughout the systemic circuit. So we'll be investigating these two circuits of blood flow today using this diagram here.
So what I want to do first is to label the different structures in our heart, so that as we explain the pulmonary and systemic circuit you'll have a better understanding of what I'm talking about.
So this chamber of our heart right here is our right atrium. Hope you can read that OK. And then this is our right-- I'm just going to abbreviate R for right-- ventricle. So then over here we have our left atrium and our left ventricle.
So as I had mentioned a few minutes ago, our heart is divided into four chambers and two halves. We have our left half of our heart and our right half of our heart. And each half is divided into an atrium, which is the upper chamber and a ventricle, which is the lower chamber. OK.
So we're going to start by talking about the pulmonary circuit. So the pulmonary circuit of blood flow is the circuit that's pumped by the right side of our heart. So this side of our heart here is responsible for our pulmonary circuit of blood flow.
So our pulmonary circuit delivers oxygen lacking blood from the right side of our heart up to our lungs-- so this is labeled as lungs-- up to our lungs and then to the left side of the heart. And then our systemic circuit delivers oxygen rich blood from the left side of our heart throughout the body and then back to the right side of our heart.
So when we're dealing with our pulmonary circuit, we're dealing with blood that is oxygen lacking. OK. So our pulmonary circuit, it has blood that's coming from the body. So this blood here, the oxygen that was in this blood has already been used up by the body and by its tissues. So this blood that's low in oxygen, or that's oxygen lacking, is delivered to the right atrium, moves into the right ventricle, and then is pumped up to the lungs.
Now once it reaches the lungs, it will be able to latch onto more oxygen. It will become oxygen rich. And then it will flow into our left atrium, down into our left ventricle. And from there this oxygen rich blood is pumped to our body's tissues. So our systemic circuit then is dealing with oxygen rich blood.
OK. So pulmonary circuit is delivering blood to the lungs to collect oxygen. And then our systemic circuit is delivering that oxygenated blood throughout our body. OK.
So this lesson has been an overview on the pulmonary and systemic circuits of blood flow.
One of the two circuits of blood flow in which the right side of the heart pumps blood low in oxygen to the lungs and returns it to the left atrium.
One of the two circuits of blood flow in which the left side of the heart pumps oxygen rich blood to the body and returns it to the right atrium.