Epiglottis

Epiglottis Definition

It is a thin, flexible lid-like cartilaginous structure at the root of the tongue that leads into the windpipe. It is often mistaken as uvula. It is clearly visible as an elongated high-rising tissue in the oropharynx. It is, however, more prominent in a fetal pig.

Epiglottis Pronunciation

It is pronounced as ep-i-glot-tis.

Epiglottis Etymology

It is derived from the Greek word “epiglossa”, meaning tongue.

Epiglottis Location

It is usually located between the lower section of the pharynx and the vocal cords. It projects obliquely upwards behind the tongue and the hyoid bone.

Location of Epiglottis

Epiglottis Anatomy/Histology

It is made of yellow elastic cartilage tissue, lined with a mucous membrane. In fact, it is one of nine cartilaginous structures that constitute the larynx. It comprises of the lingual and laryngeal surface, with respect to the oral cavity and larynx. A layer of stratified squamous non-keratinized epithelium covers the lingual portion and the apical region of the laryngeal surface. Taste buds are also found on this cartilage plate. As the cartilage flap has a significant role in respiration, it is also composed of pseudostratified, ciliated columnar cells and mucus secreting Goblet cells. At the petiole aspect, it is attached to the inner surface of the thyroid cartilage laminae above the anterior commissure, and projects posteriorily into the pharynx. Normally, the hypopharynx extends from its juncture with the orophraynx at the tip of the epiglottic structure. There is a slight depression behind the root of the tongue between the folds in the throat called epiglottic vallecula.

Epiglottis Innervation

The upper part of the cartilaginous mass, contributing to the afferent limb of the gag reflex, is supplied with fibers from the glosssopharyngeal nerve (CN IX). Similarly, the superior laryngeal branch of the vagus nerve (CN X) sends fibers to the lower section of the glottis that contribute to the efferent limb of the cough reflex.

Epiglottis Function/Purpose/Use

It provides sufficient space for the vocal folds, and holds the vocal cords tightly for development and production of speech. This is one of the main reasons for its evolution. The flexible cartilage is particularly helpful in pronunciation. During inspiration, it points upwards and thus, functioning as a part of the pharynx. However, the hyoid bone rises during swallowing and pulls the larynx upward in order to prevent the food from entering the trachea. For this reason, a distorted cartilage can hurt an individual while swallowing both solid food and fluids.

Epiglottis Diseases

The valve-like structure is prone to a host of infections, especially in the paediatric population. Acute epiglottitis, caused by bacteria like Haemophilus influenzae and Streptococci in the trachea, is a common condition of the glottis that results in severe inflammation and pain. Unlike croup, the ailment is less severe. A swollen epiglottis can cause respiratory failure due to its close proximity to the windpipe. An enlarged glottis may appear as a small lump/bump on the outside of the neck, which is often mistaken for hernia. This could be a medical emergency since a malfunctioned structure diverts the food into the trachea and cause choking. On a lateral C-spine X-ray, a thumb sign indicates an inflamed epiglottic mass. Tracheal bleeding, granulation, and spasm are the most common health issues of nursing interventions such as tracheostomy, conducted as a part of diagnosis. Nevertheless, in most countries the disease has become rare with the advent of Haemophilus influenza vaccine. Cancer of the larynx can often occur on the supraglottis, which includes the cartilaginous flap. Although malignant epiglottic growths produce mild symptoms, it is possible to detect the problem at an early stage if the sufferer has a persistent hoarse voice. Frequent cough, sore throat, and difficulty in breathing are some of the other symptoms of the disorder. In severe cases, healthcare experts remove the damaged structure. Despite proper treatment, most patients have a 5-year survival rate.

Approximately 40% of patients with Pallister-Hall syndrome are affected with bifid epiglottis, a rare congenital anomaly that causes a midline-cleft of the leaf-shaped flap of cartilage. Epiglottic dysfunction can, however, be corrected with the aid of surgery. Sometimes, laryngomalacia in infants and young children is responsible for producing high-pitched wheezing sound in the upper airway. Here, the supraglottic larynx is tightly curled on itself to give an “omega-shaped” structure. The condition can get fatal when the floppy tissues fall over the airway opening and cause obstruction. In some cases, bulimia nervosa-affected patients have reported a non-working, weak glottis due to gastroesophageal reflux disease (GERD). Constant bouts of acid regurgitation can lead to epiglottic ulcers.

Epiglottis Pictures

Epiglottis Picture

 

Epiglottis Photo

Epiglottis Frequently Asked Questions

The answers to the most frequently asked questions about the lid-like cartilaginous structure are given below:

What is the exact job of epiglottis?

In simple words, the cartilaginous flap prevents food from entering the trachea.

How does one know when the epiglottis is not working right?

Immediate medical attention is required if someone displays symptoms such as difficulty swallowing, muffled voice or breathing problems.

Is the epiglottis prone to attack by virus?

Viral infection of the epiglottis is a common condition seen in young children due to a weak immune system.

Which organ system does the epiglottis belong to?

It is belongs to both digestive and respiratory system.

Are there any exercises for improving the condition of a dysfunctional epiglottis?

Healthcare professionals often advice patients, suffering from epiglottic inversion, to perform some exercises for proper movement of the cartilaginous mass. Mendelsohn maneuver, epiglottis control and shaker exercise are some of the therapeutic methods followed for strengthening the muscles of the affected cartilage.

Can food get stuck in the epiglottis?

This problem is common in dysphagia-affected patients who experience difficulty swallowing.

Is epiglottis related to hiccups?

According to many medical experts, sharp closure of the cartilaginous structure produces the characteristic ‘hic’ sound of hiccups.

References

http://en.wikipedia.org/wiki/Epiglottis

http://www.innerbody.com/image_digeov/dige02-new2.html

http://www.nlm.nih.gov/medlineplus/ency/imagepages/19595.htm

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