The epiglottis is a small, leaf-shaped flap of cartilage in the throat. It helps direct substances toward the correct pathway, ensuring air enters the lungs and food or liquid goes into the digestive tract.
The Critical Role in Swallowing
The primary function of the epiglottis unfolds during swallowing. As food or liquid moves from the mouth toward the throat, the larynx, which houses the vocal cords, moves upward and forward. Simultaneously, the epiglottis swings backward and folds down like a lid, covering the opening of the larynx and windpipe.
This action effectively blocks the entrance to the respiratory tract, preventing food or liquids from entering the lungs. Instead, the swallowed material is directed into the esophagus, a muscular tube. The epiglottis’s movement is influenced by the tongue pushing food down, the upward pull of the hyoid bone, and muscle contractions. This coordinated closure is why it is not advisable to talk while eating, as it increases the chance of food entering the airway. Once swallowing is complete, the epiglottis returns to its resting, upright position.
Beyond Swallowing: Facilitating Breathing
The epiglottis also plays a continuous, though passive, part in respiration. When not engaged in swallowing, it remains in an upright and open position. This posture allows for an unobstructed pathway, ensuring air flows freely into and out of the larynx and lungs.
This open state provides the airflow needed for breathing. The epiglottis’s flexibility allows it to maintain this open position. Its normal position also enables the production of speech sounds, as air can move past the vocal cords.
When the Epiglottis Malfunctions
Dysfunction of the epiglottis can lead to health concerns related to the misdirection of food or liquids. If it fails to close completely during swallowing, substances can enter the trachea and potentially reach the lungs. This event, known as aspiration, can cause coughing or choking as the body attempts to expel the foreign material.
Repeated aspiration can lead to conditions like aspiration pneumonia, a lung infection. The epiglottis itself can also become inflamed and swollen, a condition called epiglottitis. This is often caused by bacterial infections, though other bacteria or viruses can also be responsible.
Symptoms of epiglottitis can develop rapidly and include severe sore throat, pain and difficulty swallowing, muffled voice, and difficulty breathing. Swelling of the epiglottis can obstruct the airway, making it a medical emergency that requires immediate attention to prevent severe breathing difficulties or complete airway blockage.