During childhood, stridor is usually caused by infection of the cartilage flap (epiglottis) that covers the opening of the trachea to prevent material from entering the lungs and choking a person during swallowing.
Because epiglottitis involves swelling and infection of tissues, which are all located at or above the level of the epiglottis, it is sometimes referred to as supraglottitis (supra meaning above).
The epiglottis normally prevents substances that have been swallowed, as well as substances that have been regurgitated (vomited), from heading down through the larynx into the lungs.
When the epiglottis (the flap that covers the trachea during swallowing so that food odes not enter the lungs) is infected, it can swell to the point where it blocks the windpipe.
Because the vocal cords are located in the larynx just below the area of the epiglottis, the swollen epiglottis makes the patient's voice sound muffled and strained.
Another serious disease stemming from this pathogen is epiglottitis, an infection of the epiglottis that cause swelling of the airways and potential death.
Because the swollen epiglottis interferes significantly with air movement, every breath creates a loud, harsh, high-pitched sound referred to as stridor.
Because the epiglottis may swell considerably, there is a danger that the airway will be blocked off by the very structure designed to protect it.
This embraces the base of the epiglottis, and, except while swallowing food, shuts off all communication between the cavity of the mouth and the pharynx, respiration being, under ordinary circumstances, exclusively through the nostrils.
Again, from different points of the cortex the assunIption of the requisite positions of the tongue, lips, cheeks, palate and epiglottis, as components in the act of sucking, can be provoked singly.