The circulatory system is in charge of pumping, transporting, and distributing blood, nutrients, oxygen, and hormones throughout the body. It is made up of three independent organs that work together: the heart (cardiovascular system), the lungs (pulmonary circulation), and the arteries and veins (systemic circulation).
What does the heart do?
An average adult has about five liters of blood in the body. Also, blood is made up of red blood cells, white blood cells, plasma, and platelets. Likewise, the heart is the muscle that pumps blood, rich in nutrients and oxygen, to all parts of our body.
This organ, which usually beats between 60 and 100 times per minute, contains four chambers in which blood flows. In each beat, blood enters the right atrium and passes through the right ventricle, which is responsible for pumping blood to the lungs where it is oxygenated.
Pulmonary and systemic circulation
The pulmonary circulation carries blood between the heart and the lungs. That is, it sends deoxygenated blood to the lungs to absorb oxygen and subsequently release carbon dioxide. Afterward, the oxygenated blood returns to the heart.
In the systemic circuit, the arteries, veins and blood vessels are responsible for transporting blood , oxygen and nutrients from the left ventricle of the heart to the aorta, the largest artery in our body. Blood travels from the aorta through the systemic arteries and subsequently reaches the arterioles and capillary beds that soak into the body’s tissues.
Then, the deoxygenated blood travels through the capillary beds until it reaches the systemic veins. Systemic veins reach the superior and inferior vena cava, the largest veins in the body. Finally, the vena cavae send the deoxygenated blood to the right atrium of the heart.
On the other hand, the blood vessels of the human body measure approximately 100,000 kilometers, that is, more than twice the circumference of our planet. The network of arteries carries oxygen-rich blood from the heart through the body, while the veins send oxygen-poor blood back to the heart.
