Circulatory System

Blood Flow Route

Body → Vena cava → Right atrium → Right ventricle → Pulmonary artery → Lungs → Pulmonary vein → Left atrium → Left ventricle → Aorta → Body.

Vena cava

Largest veins; return oxygen-poor blood from the body to the right atrium.

Right atrium

Receives oxygen-poor blood from the body.

Right ventricle

Pumps oxygen-poor blood to the lungs.

Pulmonary artery

Carries oxygen-poor blood from the right ventricle to the lungs.

Lungs

Add oxygen to the blood and remove carbon dioxide.

Pulmonary vein

Carries oxygen-rich blood from the lungs to the left atrium.

Left atrium

Receives oxygen-rich blood from the lungs.

Left ventricle

Pumps oxygen-rich blood to the body.

Aorta

Largest artery; carries oxygen-rich blood from the left ventricle to the body.

Arteries

Carry blood away from the heart.

Veins

Carry blood back toward the heart.

Capillaries

Exchange oxygen and nutrients for waste and carbon dioxide.

RBC / Erythrocyte

Red blood cell that carries oxygen.

WBC / Leukocyte

White blood cell that fights infection.

Platelet / Thrombocyte

Helps blood clot and stop bleeding.

Plasma

Liquid portion of unclotted blood; contains clotting factors.

Serum

Liquid portion after blood clots; plasma without fibrinogen and most clotting factors.