Atria

The atrium is one of the four chambers of the heart, which is the first link in the blood circulation. It receives blood from the veins and pumps it into the ventricles of the heart for further circulation throughout the body.

Anatomically, the atrium is located above the ventricles and is separated from them by valves that ensure proper blood flow. In total, the atrium consists of two sections - right and left. The right atrium receives blood from the inferior and superior vena cava, which collect blood from the body and head. The left atrium receives blood from the pulmonary veins, which collect blood from the lungs.

The blood entering the atrium is rich in oxygen and nutrients, which it receives in the lungs and digestive organs. After blood enters the atrium, it passes through the valves and into the ventricles of the heart, which contract and release the blood into the arteries to transport it throughout the body.

The atrium plays an important role in the normal functioning of the cardiovascular system. Any disturbance in the atrium, such as arrhythmia or valve disorder, can lead to serious consequences such as circulatory failure and heart failure.

In conclusion, the atrium is an important chamber of the heart that ensures proper flow of blood into the ventricles of the heart. It receives blood from the veins, rich in oxygen and nutrients, and passes it on for further circulation throughout the body. Therefore, any disruption in its functioning can lead to serious health problems.

The atrium is a cavity with an inner lining - the endocardium (epicardium cordis). Between them there is loose tissue - fibro-elastic. The inner shell is thickened twice as much as the others, has many folds, the surface of which is cut with holes for the passage of venous vessels. The upper wall is immersed in the body of the inferior vena cava and two azygos veins and one semi-gypsy vein flow along it. The lower wall in the middle runs parallel to the median plane of the body and with its branches reaches the superior vena cava. In front of it there are branches of the right and left ventricles of the heart.