tenâ¢or /ËtÉnÉ/USA pronunciation n. the course of meaning that runs through something written or spoken; drift:[countable]The tenor of the meeting was one of tenseness. continuous course or movement:[countable]nothing to disturb the tenor of our lives. Music and Dance [uncountable] the adult male voice between the bass and the alto.
The pulmonary artery carries deoxygenated blood from the heart to the lungs and is the only artery in the body that carries deoxygenated blood. The pulmonary vein carries oxygenated blood from the lungs to the heart, and it is the only vein that carries oxygen-rich blood.
Three sets of vessels comprise the circulatory system: arteries, lymphatics, and veins. Arteries bring oxygen-carrying blood from the heart to the tissues. In the normal course of blood circulation, small amounts of fluid and protein leak from arteries and veins. Lymphatic vessels bring this protein-rich fluid back into the circulation. The third type of blood vessel is the vein. Veins bring oxygen-depleted blood from the organs and tissues to the heart and lungs, where it is re-oxygenated. Blood return to the heart tends to be passive and is enabled by muscle contraction in the arms and legs.