What is the epiglottis?
The epiglottis is a flap of elastic cartilage that is covered with a mucous membrane and located at the root of the tongue. It is part of the larynx, more precisely; it is located in front of it (separating the root of the tongue from the laryngeal cavity). The epiglottis is usually upright at rest allowing air to pass into the larynx and lungs and food to pass into the gastrointestinal tract.
The epiglottis serves to prevent the body from choking on food that would normally damage the airway. When an individual swallows, the epiglottis folds backwards and chewed food and saliva go directly into the gastrointestinal tract, preventing access to the windpipe and lungs. After swallowing, it returns to its original upright position.
The epiglottis has the shape of a large leaf, round at the top and narrow at the base. It is lower end (ie the end facing the cavity of the larynx) is connected by two tiny ligaments: the thyroepiglottic and hyoepiglottic ligaments, which hold the epiglottis in its resting position at the throat. The thyroepiglottic ligament connects the inferior point of the epiglottis to the thyroid cartilage of the larynx, while the hyoepiglottic ligament connects the anterior surface of the superior region to the hyoid bone.
The contour of the epiglottis is characterized by a top edge and two side edges .The mucous membrane covering the upper anterior part of the epiglottis reflects off the sides of the epiglottis, giving rise to the glossoepiglottic folds. The aryepiglottic folds are folds of mucous membrane that extend up to the apex of the arytenoid cartilage, or cartilage of the complex skeletal muscles (vocal ligaments and intrinsic muscles of the larynx) that play an important role in regulating vocal folds.
A common condition associated with epiglottis is known as epiglottitis. Epiglottitis is a medical emergency that occurs when tissue in the epiglottis becomes inflamed. Common symptoms may include high temperature, difficulty swallowing, sore throat and breathing complications. When the epiglottis becomes infected or inflamed, it can cause damage or close off the windpipe, which can result in death if not treated properly. Seeking immediate medical attention is vital in order to determine the most appropriate form of treatment (antibiotics, tracheal intubation, tracheostomy, etc) and prevent symptoms from worsening. In most cases, a full recovery can be expected if the condition is treated immediately.
What function does the epiglottis serve?
The primary function of the epiglottic cartilage is to prevent chewed food and saliva from entering the trachea, resulting in choking. For this reason, the epiglottis folds backwards during swallowing movements as to cover the opening of the larynx so that food and liquid are directed to the esophagus. After swallowing, the epiglottis returns to its original position and the opening of the larynx closes.
If food or liquid enter the windpipe while epiglottis fails to close properly, the gag reflex is introduced as a means to protecting the respiratory system. The gag reflex involves a reflex contraction that prevents something from entering the throat except as part of the normal swallowing process in order to help prevent choking.
