Role in Respiration
Unlike the trachea and bronchi, the upper airway is a collapsible, compliant tube. As such, it has to be able to withstand suction pressures generated by the rhythmic contraction of the diaphragm that sucks air into the lungs. This is accomplished by the rhythmic contraction of upper airway muscles, such as the genioglossus (tongue) and the hyoid muscles. In addition to rhythmic innervation from the respiratory center in the medulla oblongata, the motoneurons controlling the muscles also receive tonic innervation that sets a baseline level of stiffness and size.
Read more about this topic: Upper Respiratory Tract
Famous quotes containing the word role:
“I wish glib and indiscriminate critics of industrialists had some conception of the problems that have to be met by factory management.... General condemnation of employers is a favorite indoor sport of the uninformed intelligentsia who assume the role of lance- bearers for labor.”
—Mary Barnett Gilson (1877–?)