Question

The __________ circuit carries blood to and from lungs.

Short answer

Pulmonary circuit.

Step-by-step solution

Understand the Types of Circulatory Circuits

In human biology, there are two main types of circulatory circuits: the systemic circuit and the pulmonary circuit. The systemic circuit carries blood to the entire body, while the pulmonary circuit is responsible for carrying blood to the lungs and back.

Identify the Circuit Related to Lungs

The pulmonary circuit specifically deals with transporting deoxygenated blood from the heart to the lungs, where it is oxygenated, and then returns the oxygenated blood back to the heart.

Key concepts

Circulatory Circuits

In our bodies, the process of blood circulation is divided into two main types of circuits: the systemic and pulmonary circuits. These circuits work together to ensure that blood is continuously moving and delivering vital substances throughout the body.

• The **pulmonary circuit** carries blood to and from the lungs. It has a crucial role in oxygenating blood and removing carbon dioxide.
• The **systemic circuit** carries oxygenated blood from the heart to the rest of the body and returns deoxygenated blood back to the heart.

Each circuit has unique roles but they function cooperatively, creating a complete system that sustains life by ensuring each cell receives oxygen and nutrients, and waste products are removed efficiently.

Systemic Circuit

The systemic circuit is dedicated to supplying our entire body with oxygenated and nutrient-rich blood. After blood is pumped from the left side of the heart, it travels through arteries to various tissues and organs.

• This circuit begins at the **left ventricle** of the heart, where oxygenated blood is delivered by the lungs. It is then pumped into the aorta.
• The **aorta**, the largest artery, branches into smaller arteries to reach different parts of the body.
• Once the blood’s oxygen is used by the body, it returns as deoxygenated blood through veins back to the **right atrium** of the heart.

This complete process ensures that our muscles, brain, and other vital organs receive the necessary oxygen and nutrients to function properly.

Oxygenation of Blood

Oxygenation of blood is a critical process that happens in the pulmonary circuit. When blood circulates to the lungs, it exchanges carbon dioxide for oxygen. This is essential for the body's metabolism.

• Deoxygenated blood travels from the **right ventricle** of the heart through the **pulmonary artery** to the lungs.
• In the lungs, **capillaries** surrounding the alveoli allow for gas exchange - oxygen enters the blood, and carbon dioxide is expelled when we breathe out.
• The now oxygen-rich blood returns via the **pulmonary veins** to the heart's **left atrium**.

This oxygenated blood is then ready to be pumped through the systemic circuit, supplying the body with the necessary oxygen to sustain cellular functions.