Confidence votes 22. The circulatory system includes the heart, arteries, veins, capillaries, and blood. The heart functions as a muscular pump that helps force blood through the blood vessels.The blood serves as a fluid for transporting gases, nutrients, hormones, and wastes.onfidence votes 22. The circulatory system includes the heart, arteries, veins, capillaries, and blood. The heart functions as a muscular pump that helps force blood through the blood vessels.