Learn about the circulatory system parts and understand the circulatory system functions. See the main organs and tissues that make up the circulatory system.

An earthworm's circulatory system includes the dorsal blood vessel, five hearts, and a ventral blood vessel that carries blood throughout the worm's body in a closed loop.

The circulatory system is defined as a body system that has the primary function of transporting oxygenated blood throughout the body, and the key organ that does this is the heart.

Learn about the components of the circulatory system. Examine the main components of the cardiovascular system and identify functions of the cardiovascular system.

The main function of the circulatory system is to bring oxygen and nutrients to all of the cells in the body and remove metabolic waste.

The function of the circulatory system is to move blood around the body. Discover the parts of the circulatory system, such as the heart and types of blood vessels, and how they work together.

Veins are an important part of the cardiovascular system. Their main function is to bring deoxygenated blood back to the heart. The circulatory system is named as such because it is …

Learn about the circulatory system parts and understand the circulatory system functions. See the main organs and tissues that make up the...

Discover the vital functions of a bird's circulatory system in our engaging video lesson. Learn its heart structure and test your knowledge with a quiz!

Learn about the octopus's unique circulatory system, with three hearts and a complex brain, in this 5-minute video. Then, take a quiz to test your knowledge.