Parotid gland. 19th century artwork showing the microscopic structure of a parotid salivary gland, which is located just below the ear. Lobules of secretory cells are white. Their secretions drain into ducts, which eventually empty into the oral cavity. Arterioles are red and venules are blue. that This anatomical artwork is plate 16 from volume 5 (1839) of 'Traite complet de l'anatomie de l'homme' (1831-1854). This 8-volume anatomy atlas was produced by the French physician and anatomist Jean-Baptiste Marc Bourgery (1797-1849). The illustrations were by Nicolas-Henri Jacob (1781-1871).