NEET PG DENTAL EXAM

Detailed explanation-1: -Earthworms (Pheretima) have closed blood vascular systems, which consists of the heart, blood vessels, and capillaries. The heart pumps blood for circulating it in one direction.

Detailed explanation-2: -Lateral vessels supply all segments and organs in the earthworm’s body. After gas and nutrient exchange occurs, a small blood vessel in each segment returns blood from the ventral blood vessel to the dorsal blood vessel, thus closing the loop of the circulatory system.

Detailed explanation-3: -Earthworms have what are called closed circulatory systems. Closed circulatory systems are those in which the blood is kept in a closed system of vessels, like in humans. Open circulatory systems are when the blood is pumped into a body cavity called a hemocoel, allowing the blood to surround the organs.

Detailed explanation-4: -Insects, like all other arthropods, have an open circulatory system which differs in both structure and function from the closed circulatory system found in humans and other vertebrates. In a closed system, blood is always contained within vessels (arteries, veins, capillaries, or the heart itself).