Respiratory anatomy, 19th Century artwork. Historical hand coloured lithographic print showing the trachea (wind pipe, vertical) running down from the larynx (voicebox, top centre) and branching (centre) into the two bronchi. These then branch further into numerous bronchioles inside each lung (left and right). Image from 'Traite complet de l'anatomie de l'homme, comprenant la medecine operatoire' Vol. 4 (1836), by Jean-Baptiste Marc Bourgery and illustrated by Nicolas-Henri Jacob.