Britannica
Sources used in this answer
How does breathing help blood return to the heart through veins?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Circulatory system
Human circulatory system.
Breathing assists in the return of blood to the heart by creating changes in pressure within the chest cavity. As you breathe, these pressure fluctuations help draw blood upward toward the heart, which is particularly important for facilitating venous return from the legs.12
This process works in conjunction with other mechanisms that ensure efficient blood flow despite the effects of gravity, including:
- One-way valves: These structures within veins prevent blood from flowing backward.12
- Skeletal muscle contractions: As surrounding muscles contract during movement, they squeeze the veins, effectively propelling blood toward the heart.12
Together, these mechanisms compensate for the low blood pressure found in the venous system, ensuring that oxygen-depleted blood is successfully returned to the heart to complete the systemic circulation.2