Question

Explain why fish do not need a three-chambered or four-chambered heart for proper circulation.

Answer 1

The heart of a fish has two chambers, an atrium and a ventricle. Deoxygenated blood arrives from the body, enters the atrium and then the ventricle where it is pumped to the body via the gills.

Blood is pumped from the heart through the capillary beds of the gills and through the capillary beds of the tissues. Blood slows down when it enters the capillary beds of the gills. It is moving slowly on its way to the tissues and needs skeletal muscular action to assist blood to move back to the heart.So the fish relies on physical movement for blood to be recirculated back to the heart.

If land based mammals were to rely on this method to return blood to the heart they would die from exhaustion. Water supports the mass of the fish but on land where there is no buoyant force gravity would take its toll on the animal.

Gills are tissues that are like short threads, protein structures called filaments. These filaments have many functions including the transfer of ions and water, as well as the exchange of oxygen, carbon dioxide, acids and ammonia.

Since in a fish Blood Pumped from the ventricle(Deoxygenated) Pass through The capillary beds of Gills,there is Exhange of Oxygen and CO2 like Lungs.Then The Oxygented Blood Moves from gill to the Tissues.From there fish relies on physical movement for blood to be recirculated back to the heart, Water supports the mass of the fish.So a Fish do not need a three-chambered or four-chambered heart for proper circulation

Because blood leaves the gills and immediately circulates to the rest of the body and fish relies on physical movement for blood to be recirculated back to the heart.The heart does not require additional chambers beyond the first two