During diastole the atria fills with blood.
The heart of fish have two chambers. The heart of reptiles and amphibians have three chambers. The heart of mammals have four chambers.
A shark heart has two chambers.
The atria are the upper chambers of the heart that receive blood returning from the body (right atrium) and the lungs (left atrium). They contract to push blood into the ventricles for efficient circulation.
the human heart contains four chambers and it is the ventricles (the two lower chambers) that do the pumping
There are four chambers in the human heart. There are two atria (the two upper chambers) and two ventricles (the two lower chambers).
the upper chambers of the heart are called the right and left atrium and they are the receiving chambers of the heart
The cardiac ventricles are the two lower chambers of the heart's four chambers. They are larger and more narrowed than the atria. They function by collecting the blood that flows into them from the atria and then contract in order to expel blood into the peripheral tissues, using major vessels to carry it to the extremities and lungs.
A mouse has four heart chambers, similar to other mammals. These chambers include two atria and two ventricles, which work together to pump blood throughout the body.
The two top chambers of the heart are called the right and left auricle respectively
The upper two chambers of the heart are the right atrium or auricle, and the left atrium or auricle.
They have one chamber to their heart: a single tube connected to two valves at either end, and a muscle to help it contract.
Clams have the most complex heart of the mollusks, with 3 chambers.