What type of circulatory system does the lancelet have?

The lancelet has a closed circulatory system, there is an arterial and venous chain. The branchial arteries work instead of the heart. The largest vessel is the abdominal aorta from which arteries branch off. In the dorsal region, they again gather in the dorsal aorta, and from it the vessels supplying the tissues of the body are broken. The venous system is represented by the jugular veins (carry blood back) and the cardinal veins (forward). Veins collect in the Cuvier duct, then into the venous sinus, which already passes into the abdominal aorta.