Question

If oxygenated blood flows in arteries and deoxygenated blood flows in veins then why does blood come in the left atrium through the pulmonary vein and goes out from the right ventricle through a pulmonary artery in the heart?

Answer 1

The heart is a vital organ in the circulatory system since it generates pressure and thereby allows blood to circulate across the system and pulmonary circulatory systems. There are four chambers in the heart: two atria and two ventricles.

Complete answer:
The heart is a hollow, muscular organ that pumps both oxygenated and deoxygenated blood across the body and to the lungs. There are four chambers in this important circulatory system structure. Blood with waste (from the body) is received in one chamber on the right, and it is pumped out to the lungs, where the waste is exhaled.

The left chamber absorbs oxygen-rich blood from the lungs, while the right chamber pumps nutrient-rich blood into the body. Blood flow inside the heart's chambers is regulated by two valves, and blood flow out of the heart is controlled by two valves.

The right ventricle and the left ventricle are the two bottom chambers. These are the pumps that remove blood from the heart. Between the two ventricles is a wall called the interventricular septum.
The right atrium and the left atrium are the two upper chambers. They take in the blood as it enters the heart. Between the atria is a wall called the interatrial septum.

Arteries transport blood away from the heart and into capillaries, where it is oxygenated (along with other nutrients) and delivered to tissue and cells. As oxygen is withdrawn from the blood, it returns to the lungs, where it is reoxygenated and returned to the heart through veins.

The pulmonary arteries transport deoxygenated blood from the right ventricle to the lungs' alveolar capillaries, where carbon dioxide is released and oxygen is taken in. These are the only arteries that hold deoxygenated blood, and they are classified as arteries because they transport blood away from the heart. The left and right pulmonary arteries, which carry deoxygenated blood to the lungs, branch off from the short, large vessel. When blood is ejected through the pulmonary arteries, it first passes through the pulmonary valve.

Pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart. This huge artery is classed as a vein since it sends blood to the heart, despite the fact that it contains oxygenated blood. The left atrium is crossed by four pulmonary veins. The right atrium and superior vena cava are behind the right pulmonary veins, while the left pulmonary veins are in front of the descending thoracic aorta. The pulmonary arteries and veins are also part of the pulmonary circulation system.

Note: The colour of blood is always red. Some people claim that deoxygenated blood is blue because veins look blue when seen through our skin. This is not the case, however. The way tissues absorb light and our eyes perceive colour causes blood to look blue. Although the amount of oxygen in the blood has an impact on its brightness (more oxygen = brighter red, less oxygen = darker red), blood is never actually blue.