One of the main functions of the larynx is swallowing. The epiglottis is the most important player in this process, which is essential for survival – without it, no food intake would be possible. A complex interplay guided by nerves ensures that nutrients can be delivered to the body.
What is the epiglottis?
The laryngeal epiglottis (lat. the epiglottis) is a component of the larynx (lat. larynx). In addition to the cricoid cartilage and the thyroid cartilage, the epiglottis represents the third, of the three major cartilages of the larynx. It is thus an essential component of the human respiratory system. It is responsible for ensuring that neither liquid nor solid food can enter the trachea during eating and drinking. If this does happen, the person swallows. Dysfunctions are unpleasant and, in the worst case, can be life-threatening. Since the adult human swallows about two thousand times a day, it is essential that the swallowing process runs smoothly. During the swallowing process, neither breathing nor speaking are possible – and the same applies vice versa.
Anatomy and structure
The epiglottis is a cartilaginous plate. It is located directly above the trachea and is covered with mucosa. It is attached to the inner side of the Adam’s apple (the thyroid cartilage) by a ligament. The anatomical components are a stalk (lat. Petiolus epiglotticus) and a body. Unlike the rest of the larynx, which is mainly lined with lung mucosa, the laryngeal epiglottis is covered with the mucosa that is also found in the mouth area. During swallowing, the larynx is pushed forward and the epiglottis closes the trachea by covering the entrance. This process is passive; conscious control is not possible. But the epiglottis is not only responsible for closing the trachea. It also lays over the esophagus during breathing. In order for the epiglottis to perform its tasks, it is controlled by nerves in the mucosa. The ninth and tenth cranial nerves are responsible for the swallowing mechanism. The cough and gag reflex are, of course, also due to neural afferents.
Function and tasks
Swallowing is a process in the human body that is particularly complex. As soon as a person swallows, a congestion is triggered in the pharynx. The junction of the trachea and esophagus must be controlled and kept clear each time. This works automatically due to the intelligent interaction of the nerves involved and the laryngeal cap. The laryngeal cap closes the trachea, the food pulp is transported into the esophagus, and after swallowing, the trachea is opened again. When the path to the trachea is blocked, inhalation or exhalation is not possible. Speaking is also not possible because swallowing also closes the vocal folds. Anyone who nevertheless tries to swallow and speak at the same time knows what happens. The smallest pieces of food and liquids are immediately coughed up again with a violent fit. Only very rarely is this reflex not relied upon. The fact that larger amounts of food (or vomit) enter the respiratory tract happens with unconscious people, in an alcoholic state, with small children or in the case of anesthesia. If this is the case, it can lead to dangerous pneumonia and, in the worst case, death by suffocation.
Diseases
Chronic dysphagia is a condition suffered by people affected by neurological diseases. When a nerve conduit is disrupted or fails, the entire process becomes disorganized. Swallowing and coughing fits are the order of the day. An inflammatory disease of the epiglottis is also known. It frequently affects children (preschool age), but adults can also contract it. However, due to the availability of medication, epiglottitis occurs rather rarely nowadays and can be treated well with antibiotics if it is detected in time. This ensures that it heals without any consequences. Causes of the infection are bacteria: “Haemophilus influenzae” and more rarely pneumococci. Symptoms of epiglottitis are a foreign body sensation when swallowing, in addition, shortness of breath sets in very quickly, as the laryngeal larynx swells. When children have epiglottitis, they very often refuse to lie down because it makes it harder for them to breathe.Relief is provided if they can sit bent over in front and support themselves on their arms. Increased salivation and fever are also symptoms of epiglottitis. Going to the hospital is unavoidable if epiglottitis is suspected. The disease can become acutely life-threatening if the airways close completely. If there is a risk of suffocation, the physician has no choice but to intubate or use a tracheotomy to restore breathing. Cancer can also affect the laryngeal epiglottis. So-called supraglottic carcinoma spreads from the pocket folds and epiglottis. Such squamous cell carcinomas (the cancer originates in the cells lining the inside of the larynx) first affect the larynx and then grow into the surrounding neck tissue. Once the lymph nodes are affected, therapy becomes increasingly difficult. However, as with any cancer, the success of treatment is related to when the diagnosis was made. Depending on the findings, the treating physician will use chemotherapy, radiation treatment or surgery for therapy.
Typical and common laryngeal diseases
- Laryngitis
- Laryngeal cancer
- Laryngeal paralysis
- Epiglottitis (inflammation of the epiglottis)