Outline the path that blood follows in pulmonary circulation?

Pulmonary Circulation:

1. Right Atrium: Deoxygenated blood from the body enters the right atrium through two large veins called the superior vena cava (which collects blood from the upper body) and the inferior vena cava (which collects blood from the lower body).

2. Tricuspid Valve: The blood then flows from the right atrium into the right ventricle through an opening guarded by the tricuspid valve.

3. Right Ventricle: The right ventricle contracts, pumping the deoxygenated blood into the pulmonary artery.

4. Pulmonary Artery: The pulmonary artery carries the deoxygenated blood to the lungs. It branches into two main branches, one leading to each lung.

5. Lungs: In the lungs, the pulmonary artery branches into smaller vessels called arterioles, which supply the alveoli (tiny air sacs where gas exchange occurs). Here, carbon dioxide (a waste product of cellular respiration) is removed from the blood and oxygen is picked up.

6. Pulmonary Veins: Oxygenated blood leaves the lungs via the pulmonary veins. There are four pulmonary veins, two from each lung.

7. Left Atrium: The pulmonary veins carry the oxygenated blood back to the heart, specifically to the left atrium.

8. Mitral/Bicuspid Valve: The blood flows from the left atrium into the left ventricle through an opening guarded by the mitral valve (also known as the bicuspid valve).

9. Left Ventricle: The left ventricle contracts, pumping the oxygenated blood into the aorta.

10. Aorta: The aorta is the largest artery in the body, and it carries the oxygenated blood to all parts of the body, delivering essential nutrients and oxygen to tissues and organs.

The oxygenated blood then circulates through the systemic circulation before returning to the right atrium to begin the pulmonary circulation process again.