If you are looking for short answers to the question – what is the difference between pulmonary and systemic circulation? Then you are in the right place. Here, I will show you the main difference between pulmonary and systemic circulation with the flow chart, table, and diagram.
Let’s get into the article and know the basic difference between these 2 main circulations of the animal’s body.
What is the difference between pulmonary and systemic circulation
In pulmonary circulation, deoxygenated blood moves from the heart (right ventricle) to the lung through the pulmonary trunk. Lungs help to convert deoxygenated blood to oxygenated blood that backs to the heart (left atrium) through pulmonary veins. In contrast, this oxygenated blood moves from the heart to the different body parts through systemic circulation.
So, the main difference between pulmonary and systemic circulation is –
| Systemic circulation | Pulmonary circulation |
| It carries (send) oxygenated blood from the left ventricle of the animal’s heart to different parts of the body through the larger aorta. | It carries (send) deoxygenated blood from the right ventricle of the animal’s heart to the lungs through the pulmonary artery. |
| Systemic circulation carries deoxygenated blood from the body to the right atrium of the animal’s head through both the cranial and caudal vena cava. | It carries oxygenated blood from the animal’s lung to the left atrium of the heart through pulmonary veins. |
| The main vessels are the aorta and its branches, cranial and caudal vena cava. | The main vessels of pulmonary circulation are pulmonary arteries and pulmonary veins. |
| Organs involvement – viscera, limbs, left ventricle, and right atrium. | Organs involvement – right ventricle, left and right lungs, and left atrium. |
| It (systemic) helps to provide nutrients and oxygen to metabolizing cells in the animal’s body. | Pulmonary circulation helps to release carbon dioxide from the blood while absorbing oxygen. |
Table 1 shows the primary differences between pulmonary and systemic circulation. All the organs or structures involved in both pulmonary and systemic circulation in animals are pointed out with their primary functions.
I think you have already answered your question – what is the difference between pulmonary and systemic circulation? But, it will be better to see the blood flow chart from the animal’s pulmonary and systemic circulation.
Pulmonary and systemic circulation flow chart
Let’s see the flow chart both for the pulmonary and systemic blood circulation in the animal’s body –
Here, the deoxygenated blood from the right ventricle of the animal’s heart moves to the right and left lungs (dogs)through the right and left pulmonary arteries.
You know these 2 (right and left) pulmonary arteries arise from the pulmonary trunk. Again, the pulmonary trunk of the animal’s (dog) heart arises from the conus arteriosus at the base of the right ventricle.
Now the lungs convert the deoxygenated blood to oxygenated blood (purify blood) by releasing carbon dioxide and absorbing oxygen.
There are 3 – 4 pulmonary veins in the animal’s (dog) lung carry the oxygenated blood to the heart’s left atrium.
So, the blood moves from the right ventricle of the heart to the left atrium under the pulmonary circulation.
What is the main function of pulmonary circulation?
From the flow chart, you may easily understand the main function of pulmonary circulation in animals. This circulation (pulmonary) carries deoxygenated blood from the right ventricle (heart) to the right and left lung, helps release carbon dioxide from the blood, and absorbs oxygen.
This purifies the blood and sends it back to the left atrium of the animal’s (dog) heart through the pulmonary veins.
Now, blood move to the left ventricle from the left atrium and the systemic circulation start.
What are the steps of systemic circulation?
In the systemic circulation, you will see 2 major steps –
- The oxygenated blood moves from the left ventricle to the body, and
- Deoxygenated blood send back to the right atrium from the body,
In the first step, oxygenated blood moves to the different parts of the body (liver, intestine, kidney, limbs, head) through the aorta. Again, in the second step, deoxygenated blood comes back to the right atrium of the animal’s heart through the cranial and caudal vena cava.
What organs are in systemic circulation?
If you notice the systemic circulation flow chart or a diagram, you may quickly identify the different organs and structures involved in this circulation. Let’s enlist the organs and structures that are under the systemic circulation –
- The left ventricle of the heart,
- Aorta and its branches (descending, brachiocephalic),
- Visceral organs (liver, intestine, kidney, other tissues),
- Hind and forelimbs,
- Head of an animal,
- Cranial and caudal vena cava, and
- Right atrium,
What does the systemic circulation system do?
First, the oxygenated blood from the left ventricle of the animal’s heart moves to the aorta. Now, the aorta passes blood into the head and forelimb through the brachiocephalic trunk and the other different parts of the body (caudally) through the descending aorta.
You know, the brachiocephalic trunk gives off different branches to the head and forelimbs of the animals. Again, other branches from the descending aorta in the animals supply the specific area of the caudal part of the body.
From the descending aorta, the oxygenated blood moves to the liver, intestine, kidney, hindlimbs, and other body areas.
Different specific veins drain blood (deoxygenated) from these organs and tissue (liver, kidney, hindlimbs) and join with the caudal vena cava. Finally, the caudal vena cava (which carries deoxygenated blood) opens into the right atrium of the animal’s heart.
Again, the brachiocephalic trunk, along with its branches, moves the oxygenated blood mainly to the head and forelimbs.
The blood becomes deoxygenated and drains through the different specific veins from the head and forelimb into the cranial vena cava. Now, the cranial vena cave carries this deoxygenated blood and moves it into the right atrium.
A pulmonary and systemic circulation diagram
Now, both the diagrams of pulmonary and systemic circulation might also help you to clear the concept. Let’s see the diagram where I tried to show you both pulmonary and system circulation from the animals (dog) –
You may find more diagrams on other different circulation like fetal, portal, and renal here. Again, you may also read the details of fetal circulation, portal circulation, and anatomical facts of a dog’s heart from an anatomy learner.
Conclusion
I hope you got the short and specific answer to the question – what is the difference between pulmonary and systemic circulation. Here, the pulmonary circulation carries blood from the right ventricle to the left atrium of the animal’s heart. At the same time, the system circulation carries oxygenated blood in different body parts from the left ventricle of the heart of an animal.
