The epiglottis is found in the throat. The throat is a term loosely applied to the part of the neck in front of the backbone. The throat contains structures important in breathing and eating. It includes the pharynx, the larynx, part of the esophagus (oesophagus) and part of the trachea. Normally, when a person swallows, two actions take place to block off the air passage. The soft palate presses against the back of the pharynx, closing the opening to the nose. At the same time, the larynx rises and is covered by the epiglottis ( a leaf-shaped lid ). These actions force the food into its own passage, the esophagus (oesophagus) and muscular waves carry it to the stomach.
The small intestine is about 7m (7.6 yards) long and is lined with small finger-like protuberances called villi. The successful absorption of nutrients depends on their transport away from the cells of the villi into the bloodstream.
It is basically a cartilaginous flap located in the neck that covers the laryngeal inlet upon swallowing. The epiglottis protects the laryngeal inlet upon eating in order to stop food from entering the larynx into the breathing tract.
Dysfunction of the epiglottis could cause aspiration pneumonia and results in dangerous dysphagia. In this article, we will discuss the anatomy and functions of the epiglottis.
It develops from the fourth pharyngeal arch. The cartilage originates from a stem-like base. The part of the anterior surface contains ligament that connects to the surface of the thyroid cartilage, tongue, pharynx, and its sides are attached to arytenoid cartilages.
The epiglottis sits upright while breathing, and hence allows air inhaled and to be exhaled from the lungs. The distance between the origin of the surface of the epiglottis along with the tongue at the front is termed as the vallecula that’s present on every side of the folds.
The epiglottis has some taste buds which are innervated from vagus nerve’s fibres in the ganglion. It has a laryngeal and lingual surface. The former is consistent with the oropharynx posteriorly and is coated in non-keratinized stratified squamous epithelium. This epithelium covers the tip of the surface that may come into contact with all the food.
The laryngeal surface has respiratory epithelium, which consists of the pseudostratified ciliated epithelium with goblet cells (which secrete mucus). There is a space between the outer surface of the epiglottis and membrane. This space includes the adipose tissue when the hyoid bone elevates, the epiglottis flaps to cover the opening during swallowing and is achieved by three muscles:
The thyroid notch is also termed as the laryngeal prominence/Adam’s apple.
Additionally, there are three paired cartilages, i.e., that the arytenoid, corniculate and cuneiform. The three cartilages are intrinsic to the larynx and accountable for phonation. The cartilages are attached to both the vocal ligaments and are pyramidal in shape. The anterior surfaces increase a projection called the vocal procedure. It makes cricoarytenoid muscles rise that run over the borders of the medial margins of the quadrangular membrane (covers the laryngeal opening upon consuming).
The tiny corniculate cartilages sit the apices of the arytenoid cartilages. They’re found in the posterior portion of the folds. The cuneiform cartilages lie just before the cartilages inside the material of the folds. The hyoid bone is not a part of the larynx but gives rise to a number of muscles that assist with the movement of the larynx. The recurrent laryngeal nerves extend the larynx and oesophagus. This enters the larynx by passing through an opening of the thyrohyoid membrane.
The epiglottis lymphatic drainage occurs across the superior laryngeal artery, which drains into the cervical lymph nodes. Venous drainage happens to superior and inferior laryngeal veins, which drain into the left brachiocephalic vein and the internal jugular vein. It also follows exactly the identical route as the arteries.
Throughout the day, epiglottis rests at the edge of larynx just posterior to the tongue. At this posting, air can easily entre from the nose and pass through larynx and go to the lungs. It only moves when we drink or sallow something, which is a complex procedure involving the movement of structures in the head to neck.
When we eat, pharynx, hyoid, and larynx are pulled, allowing pharynx to widen in order to receive food. Hyoid movement allows the epiglottis to fold down on top of the glottis of the larynx and the opening to the breathing tract.
Food enters pharynx and moves over the anterior surface of the epiglottis; the food then passes into the oesophagus located just posterior to the pharynx.