The cardiovascular system is an amazing network made up of two main parts: pulmonary circulation and systemic circulation. Understanding how these two work is important because they help our bodies get oxygen and nutrients, while also getting rid of waste.

1. Purpose and Function:

   • Pulmonary Circulation: This part is all about exchanging gases. It takes blood that does not have oxygen from the right side of the heart to the lungs. In the lungs, we get rid of carbon dioxide and pick up fresh oxygen. The route looks like this:
     • Right ventricle → Pulmonary arteries → Lungs → Pulmonary veins → Left atrium.
   • Systemic Circulation: This part distributes oxygen-rich blood all over the body. After the lungs give oxygen to the blood, the left side of the heart pumps this blood into the aorta. From there, it travels to different body tissues and organs. The path is:
     • Left ventricle → Aorta → Body tissues → Superior/Inferior vena cava → Right atrium.

2. Pressure Differences:

   • Pulmonary Circulation works with lower pressure (about 15–30 mmHg). This lower pressure is important so that it doesn’t hurt the tiny blood vessels in the lungs.
   • Systemic Circulation, however, uses higher pressure (around 90–120 mmHg). This higher pressure is needed to push blood throughout the whole body.

3. Volume Considerations: Both circuits move about the same amount of blood. However, they do this in different ways and under different pressures because of their unique structures and jobs.

In short, pulmonary circulation helps to fill blood with oxygen, while systemic circulation makes sure that oxygen-rich blood gets to all the cells in the body. Together, they show how our cardiovascular system works in harmony.