Question

What is a venous heart?

Answer 1

Hint: The term ‘venous’ is associated with vein. Venous heart receives blood through veins and then pumps it for oxygenation. This type of heart is present in fish.

Complete answer:
We are already aware of the fact that humans do not have a venous heart. Let us discuss what exactly venous heart means.

• Venous heart is a type of heart which only pumps blood with carbon dioxide.
• The heart receives blood from the veins in the organism and then pumps it for oxygenation. It does not pump oxygenated blood.
• These types of hearts are generally found in fish.
• They have only the right side of the heart, which contains the atrium (also called auricle) and a single ventricle. With this, it is made of only two chambers, unlike human hearts which have four chambers (two auricles and two ventricles).
• The circulation of blood via venous hearts is close-looped, which means the heart is a single circuit and it pumps blood all over the body with only a single loop.
• This circulation is also called the single heart circuit.
• Deoxygenated blood circulates from the body directly to the atrium, without the need of blood vessels to carry it. Then, this deoxygenated blood moves from the atrium to the ventricle.
• Next, the blood reaches the gills for purification and oxygenation.
• It is called a venous heart as it only receives blood from veins and pumps it for oxygenation straight to the lungs.

Additional Information:
• Amphibians and reptiles have three-chambered hearts, except crocodiles.
• Birds, like humans, have a four-chambered heart.

Note: Other than oxygen transport, venous hearts, like other hearts, are also involved in the transport of nutrients, hormones and other required substances through the body. It also removes the metabolic waste generated by the body.