PATHOLOGY

Detailed explanation-1: -Fishes have a single circulation type. It has two chambers that have only a single atrium and a single ventricle. The blood from all the body parts collects into the atrium and the ventricles. The atrium collects the deoxygenated blood in a single atrium and pumps it out through a ventricle.

Detailed explanation-2: -The generalization you learned in freshman biology, that fish have a two-chambered heart, means that they have only two pumping chambers, the atrium and the ventricle, but they also have a sinus venosus and a bulbous arteriosus.

Detailed explanation-3: -Fish have 2 chambers, one atrium and one ventricle. Fish hearts draw in deoxygenated blood in a single atrium, and pump it out through a ventricle.

Detailed explanation-4: -In fishes, the heart only has one atrium and one ventricle. The deoxygenated blood that returns from the body enters the atrium, and then the ventricle, and is then pumped out to the gills where the blood is oxygenated, and then it continues through the rest of the body.