The three major parts of the circulatory system are:

• The heart: a muscular organ that pumps blood throughout the body, consisting of four chambers (two atria and two ventricles) that manage blood flow

• Blood vessels: a network of arteries, veins, and capillaries that carry blood away from the heart, back to the heart, and into tissues respectively

• Blood: the fluid that circulates through the vessels, composed of plasma and cells, responsible for transporting oxygen, nutrients, hormones, and waste products

These components work together to circulate blood, delivering oxygen and nutrients to tissues and removing waste products