Carina of trachea Carina of trachea In anatomy, the carina is a ridge of cartilage in the trachea that occurs between the division of the two main bronchi. This occurs at the lower end of the trachea (usually at the level of the 4th thoracic vertebra, which is in line with the sternal angle, but may raise or descend up to two vertebrae higher or lower with breathing). This ridge lies to the left of the midline, and runs antero-posteriorly (front to back). Foreign bodies that fall down the trachea are more likely to enter the right bronchus. The mucous membrane of the
Human-body model Human-body model The human-body model (HBM) is the most commonly used model for characterizing the susceptibility of an electronic device to damage from electrostatic discharge (ESD). The model is a simulation of the discharge which might occur when a human touches an electronic device. The HBM definition most widely used is the test model defined in the United States military standard, MIL-STD-883, Method 3015.9, Electrostatic Discharge Sensitivity Classification. This method establishes a simplified equivalent electrical circuit and the necessary test procedures required to model an HBM ESD event. An internationally widely used standard is JEDEC standard JS-001. HBM is used