Aswajith

🫀 Circulation means blood movement in the body.

It’s how oxygen, food, and waste move around using the heart and blood vessels.

But not all animals have the same kind of circulation —some have single circulation, others have double circulation.

🐟 Single Circulation (in fish)

Fish have a two-chambered heart — one atrium and one ventricle.Blood goes like this:

Heart → Gills → Body → Back to Heart

So, blood passes through the heart only once for each complete trip around the body.

At the gills, it picks up oxygen.Then it goes straight to the body to give oxygen to tissues .By the time it comes back to the heart, the pressure is low — so blood flows slowly.

That’s why fish have single circulation — only one loop of blood flow.

🐸🦎🐦🐒 Double Circulation (in amphibians, reptiles, birds, mammals)

Here, blood goes through the heart twice in one full trip.The heart has four chambers.Blood travels in two loops:

1. Heart → Lungs → Heart (to get oxygen)

2. Heart → Body → Heart (to give oxygen)

So, oxygen-rich and oxygen-poor blood stay mostly separate.This gives higher pressure and faster flow, so warm-blooded animals get energy quickly.

💡 In short

• Single circulation = one loop, one heart pass (fish).

• Double circulation = two loops, two heart passes (frogs, reptiles, birds, mammals).