There are two types of the atrium in the human heart. They both have their own functions and own duties all atrium function differently basic duty of both atria. Is the same is pumping the blood some are carry deoxygenated blood and supply other atria or chamber. And there are four types of chamber heart work as a blood-pumping organ of the body so all the parts.
The heart has is responsible for blood pumping. The left atrium holds deoxygenated blood and supply to the next atrium and other atria do the same work. But they pump the blood also all chamber made from thick fiber left atrium is also called the light atrium. The main difference between the left atrium and right atrium is deoxygenated blood left one is to hold deoxygenated blood. And supply to right one then right one supply the blood through different nerves and chamber to all body.
The function of Left Atrium:
The main function of the left atrium is holding and carrying the blood from all parts of the body. because the right atrium is not suitable for blood carrying from all parts of the body some blood cells have more oxygen as compare to the normal ones. Rich oxygen blood cell does not enter through right atrium because the outer layer of the right atrium is thin as compare to left atrium so the left atrium holds the blood of all body then transfer to all organs of the heart including right atrium.
basically all organs of the heart are working on pumping the blood and carry oxygen with blood to all others parts of the body if we define one by one all parts of heart so we can clear the point how hearts and its organs are worked because the smallest part of heart doing its job. The left atrium is carry directly blood from the lungs.