Mention briefly about the circulatory system of earthworm.

(N/A) Earthworms $(Pheretima)$ possess a closed blood vascular system,which includes the heart,blood vessels,and capillaries.
The heart pumps blood to ensure circulation in a single direction.
Blood is supplied to the gut,nerve cord,and body wall via smaller blood vessels.
Blood glands are located in the $4^{th}, 5^{th},$ and $6^{th}$ segments,which produce blood cells and hemoglobin that remains dissolved in the blood plasma.
The blood cells in earthworms are phagocytic in nature.