Two & Three Chambered Heart: How do they work? What animals have a 2 chambered heart?

We humans tend to take a lot of things for granted.We have underestimated the heart for a long time.The structure of our heart is 4 chambered, for those who have knowledge about it.It gives us an efficient system to oxygenate our blood, maintain adequate pressure, and prevent mixing of oxygenated and deoxygenated blood.

Not all animals have this luxury.Some people have only two or three chambers.They decrease the efficiency of the whole system.

Some animals have only one chambered heart.Their heart has one auricle and one ventricle.The bulbus arteriosus is the one that succeeds the ventricle.

The blood enters through the venosus.It goes into the heart from here.The pressure in the ventricle is higher than the gills, which is where the blood goes next.The thin walled gills are at risk of being damaged by high pressure of blood.The bulbus arteriosus adjusts the pressure of the blood.

The reduced pressure may prevent damage to the lungs, but it isn't enough to circulate the fluid throughout the body.The circulation of blood in the body of a fish requires a balance between low pressure for the gills and high enough for it to work.Unlike humans, fishes do not have double circulation.

The exception of crocodiles have a three chambered heart with two auricles and one ventricle.This type is more advanced than fish, but not as advanced as mammals.The ventricle has an incomplete partition which divides it into 2 sub chambers.The right sub chamber is called the calum pulmonale while the left is referred to as calm venosum.The cavum arteriosum is towards the top of the ventricle.The left ventricle is connected by a valve.

The blood moves into the sub chamber of the heart.It also fills the left ventricle due to incomplete separation.The blood moves up from the heart into the lungs.The third chamber is temporarily shut off when this comes back down.The blood moves from the left ventricle to the rest of the body.