Trachea annular ligaments of trachea. The epiglottis closes the opening to the larynx during swallowing. The trachea develops in the second month of development. It is lined with an epithelium that has goblet cells which produce protective mucins (see "Respiratory epithelium"). An inflammatory condition, also involving the larynx and bronchi, called croup can result in a barking cough. A tracheotomy is often performed for ventilation in surgical operations where needed. Intubation is also carried out for the same reason by the inserting of a tube into the trachea. From 2008, operations have experimentally transplanted a windpipe grown by stem cells, and
What Work Is terribly damaged conditions of American labor, whose circumstance has perhaps never been more wrecked.” After Levine was named Poet Laureate, "What Work Is" reached the top of Amazon.com's "Movers and Shakers" list. What Work Is What Work Is is a collection of poetry by Philip Levine. The collection has many themes that are representative of Levine's writing including physical labor, class identity, family relationships and personal loss. Its primary focus on work and the working class led to it being studied with emphasis on Marxist literary criticism. The focus on work is expressed in thematically different ways throughout the collection.