ventricles are the pumping chambers of the heart, so they have to be thicker and bigger to exert enough force to perform their function.
the difference between the ventricles and the atria is that the ventricles are thicker
atria are just the receiving chambers, it is the ventricles that actually pump the blood into the pulmonary and systemic circuits
yes, the hearts atria is bigger because its leads out the body from the lungs.
the atria
The Ventricles are bigger and rougher than the AtriumsThe Ventricles are bigger and rougher than the Atriums.sizeshapewall thickness
The walls of the ventricles of the heart aren't thinner than the atria, they are thicker. This is because they require more power as they pump blood around the body, while the atria only pump blood the short distance into the ventricles. More muscular walls are therefore needed to provide this power which is why they are thicker. The left ventricle is even thicker than the right ventricle as it requires a lot more power to pump blood all around the body. The right ventricle only pumps blood to the lungs.
When relaxed, the atria expand, and then the ventricles contract.
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.
Atria is the receiving chamber and it is located at the top while ventricles are the one responsible for pumping blood out of the heart either to oxygenate the blood or to deliver it into our systems and it is located at the bottom part of the heart
Yes, atria contracts before the ventricles.
The wall of the ventricle is thicker than the walls of the atria because the ventricle pumps blood throughout the body, and the wall of the ventricle needs to be thick snd muscular in order to do so.
The wall of the ventricles is thicker than the walls of the atria as they have to be stronger as they have to pump the blood around the body where as the atria only have to pump blood into the ventricles