What are the organs of the circulatory system?
The main organ is the heart.
The heart constantly pumps blood throughout the body. The blood travels through blood vessels which are organs of the circulatory system.
These are the types of blood vessels:
arteries: blood vessels that carry away blood from the heart to the rest of the body
arterioles: deliver blood to capillaries; controls how much blood enters the capillaries
capillaries: tiny blood vessels that connect arterioles to venules; thin walls that allow nutrients and oxygen to the tissues and absorb carbon dioxide and waste products
venules: collect blood from capillaries and drain into veins
veins: blood vessels that carry blood back to the heart