Vertebrate trachea

The trachea, or windpipe, is a tube that has an inner diameter of about 20-25 mm and a length of about 10-16cm. It extends from the larynx to the primary (main) bronchi in mammals, and from the pharynx to the syrinx in birds, allowing the passage of air to the lungs. It is lined with pseudostratified ciliated columnar epithelium cells with mucosae goblet cells which produce mucus. This lines the cells of the trachea to trap inhaled foreign particles which the cilia then waft upwards towards the larynx and then the pharynx where it can then be swallowed into the stomach.
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