According to Descartes model, the primary purpose of the heart is to transfer the heat from the heart to the rest of the body to support the circulatory, digestive, and respiratory systems.
(the primary purpose of the heart; is; to transfer the heat from the heart to the rest of the body to support the circulatory, digestive, and respiratory systems)
the primary purpose of the heart
is
to transfer the heat from the heart to the rest of the body to support the circulatory, digestive, and respiratory systems