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.
The carbon dioxide in the blood is exchanged for oxygen in the alveoli. These tiny air sacs in the lungs are only one cell thick and they are surrounded by capillaries that are also only one cell thick. Blood from the heart flows through these capillaries and collects oxygen from the alveoli.