Source: https://senecalearning.com/en-gb/definitions/double-circulatory-system/

# Double Circulatory System

The human circulatory system has three key components: blood vessels, blood and the heart. It is called a double circulatory system because blood passes through the heart twice per circuit.

The **right pump** sends deoxygenated blood to the lungs where it becomes oxygenated and returns back to the heart.

The **left pump** sends the newly oxygenated blood around the body. By the time this blood returns to the heart, it has returned to a deoxygenated state.

## Circulatory System Diagram

![Double Circulatory System for Biology GCSE Revision](https://assets-cdn.senecalearning.com/assets/images/a21483749735c016f460984cfae9e969cf9bc451-480x300.png?q=90)

## **Blood Passes Through The Heart Twice Per Circuit**

**Blood enters the heart**

Deoxygenated blood from the body enters into the right atrium of the heart.

**Blood pumped to lungs**

This deoxygenated blood is pumped out of the heart and towards the lungs by the right ventricle.

**Lungs oxygenate the blood**

At the lungs, the deoxygenated blood exchanges carbon dioxide for oxygen. This is how it becomes oxygenated (contains oxygen).

**Blood returns to the heart**

Oxygenated blood returns to the left atrium of the heart.

**Blood pumped to the body**

This oxygenated blood is pumped out of the heart and to the body by the left ventricle.

**Blood returns to the heart**

The oxygenated blood gives its oxygen to body cells in exchange for carbon dioxide. The blood becomes deoxygenated and returns to the heart.