The heart is divided by a partition or septum into two halves. The halves are in turn divided into chambers. The upper two chambers of the heart are called atria and the lower two chambers are called ventricles. The atria receive blood returning to the heart from the body and the ventricles pump blood from the heart to the body. Valves allow blood to flow in one direction between the chambers of the heart.
There's four chambers of the heart. The right and left atrium, and the right and left ventricle.
Their are 2 heart chambers.
Clams have the most complex heart of the mollusks, with 3 chambers.
Sharks have 2 chambers
A snails heart has 2 chambers.
The left atrium and right atrium receive blood coming into the heart.
the 2 lower chambers of the heart
The human heart has four chambers connected by valves. We have 2 smaller chambers on the upper half of our heart and two larger chambers on the bottom of our heart. The smaller chambers are called atria; the larger chambers are called ventricles. So we refer to these chambers as right and left atrium, and right and left ventricle.
Jawless fish, such as lampreys and hagfish, typically have a two-chambered heart consisting of a single atrium and a single ventricle. This simpler heart structure is characteristic of agnathans, an ancient group of vertebrates.
A tadpole's heart typically has two chambers, one atrium and one ventricle. This simple heart structure is sufficient for the tadpole's circulation while it is in the water and undergoing metamorphosis into a frog.
Fish
2 atria and 2 ventricle
There are 4 chambers/rooms in the heart of bird/mammal.Here are some others...Fish-2 chambers/roomsLizard-3 chambers/rooms