Trachea the trachea. The trachea is no more than 4mm diameter during the first year of life, expanding to its adult diameter by late childhood. The trachea is more mobile and of more variable length, deeper, and smaller in children. The trachea is lined with a layer of pseudostratified ciliated columnar epithelium. The epithelium contains goblet cells, which are glandular, modified simple columnar epithelial cells that produce mucins, the main component of mucus. Mucus helps to moisten and protect the airways. Mucus lines the ciliated cells of the trachea to trap inhaled foreign particles that the cilia then waft upward toward
Given name by the parents at birth. In informal situations, given names are often used in a familiar and friendly manner. In more formal situations, a person's surname is more commonly used—unless a distinction needs to be made between people with the same surname. The idioms "on a first-name basis" and "being on first-name terms" refer to the familiarity inherent in addressing someone by their given name. By contrast, a surname (also known as a family name, last name, or "gentile" name), which is normally inherited, is typically shared with other members of one's immediate family. Regnal names and religious or monastic