I believe this would be your heart because that is the only time ventricles and atria are brought up.
The Atria and Ventricles are parts of the heart not the blood. The Atria is the upper chambers of the heart and the Ventricles are the lower chambers of the heart.
Assuming you mean the atria and ventricles by "the two heart chambers", the fact that in all species the atria are smaller than the ventricles reflects the fact that the atria receive blood from either the body or the lungs and then pump it into the larger and much stronger ventricles. One-way valves between the atria and ventricles prevent backflow of blood from the ventricles to the atria. The ventricles then pump the blood received from the atria to either the oxygenating organ (i.e. gills or lungs) or the body. The much thicker walls of the ventricles reflect the fact that much greater force is needed to pump the blood throughout the body or to the lungs than is needed to pump the blood from the atria to the ventricles.
The heart.
The atria and the ventricles
The atria are on the top, and ventricles on the bottom. The atria are smaller, and the ventricles bigger. The atria receive blood coming into the heart, and the ventricles send blood out of the heart. The contraction of the atria end diastole, and the contraction of the ventricles end systole.
heart
The human body has four upper chambers within the heart, consisting of two atria (the left and right atrium) and two ventricles (the left and right ventricle). The atria are the upper chambers that receive blood, while the ventricles are the lower chambers that pump blood out of the heart. Overall, there are two upper chambers if referring specifically to the atria.
2, the atria is the upper chamber of the heart. since there is alower and upper chamber in the heart, and the upper part is the atria, do the math: four chamber divided in half (two lower and two upper and 2+2=4) equals two which gives the the number of atria!
the upper two are atria and the bottom two are ventricles
The human body has four different ventricles. They are the heart, veins, arteries, and capillaries. They are included in the circulatory and reperatory systems. By: Kitakat4145
The atrioventricular node and the bundle of HIS are the electrical conduction link between the atria and the ventricles.
left and right ventricleright ventricle and left ventricle