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
Human-body model primarily for manufacturing environments to quantify a integrated circuit to survive the manufacturing process. A similar standard, IEC 61000-4-2, is used for system level testing and quantifies protection levels for a real world ESD event in an uncontrolled environment. In both JS-001-2012 and MIL-STD-883H the charged human body is modeled by a 100 pF capacitor and a 1500 ohm discharging resistance. During testing, the capacitor is fully charged to several kilovolts (2 kV, 4 kV, 6 kV and 8 kV are typical standard levels) and then discharged through the resistor connected in series to the device under test. Human-body model