Difference Between Glottis and Epiglottis

The main difference between glottis and epiglottis is that the glottis is the opening between the vocal folds, which opens into the airway whereas the epiglottis is the superior border of the glottis. Furthermore, the size of the glottis is responsible for the voice type while the size of the epiglottis is not responsible for the voice type.  

Glottis and epiglottis are two structures found in the larynx at the opening of the windpipe. Both are responsible for the production of sound.  

Key Areas Covered 

1. What is Glottis
     – Definition, Structure, Function
2. What is Epiglottis
     – Definition, Structure, Function
3. What are the Similarities Between Glottis and Epiglottis
     – Outline of Common Features
4. What is the Difference Between Glottis and Epiglottis
     – Comparison of Key Differences

Key Terms 

Epiglottis, Glottis, Rima Glottis, Vocal Cords, Windpipe

What is Glottis 

Glottis, which is anatomically known as rima glottis, is the space between the vocal cords. The size of the space changes with the activity of the larynx. Glottis takes a narrow wedge shape during regular breath and it becomes a wide triangular shape during forced respiration.  

Figure 1: Glottis Structure

During phonation, the glottis is slit-like since the vocal cords are closed. During pronunciation, vibrations of the vocal cords produce the buzzing sounds of the human voice. 

What is Epiglottis 

Epiglottis is a cartilaginous flap, covering the laryngeal inlet during swallowing. It prevents the food from entering into the larynx. It takes the shape of a leaf and is made up of fibrocartilage. Mucosa covers the lingual surface of the epiglottis.  

Figure 2: Epiglottis

Dorsal surface of the thyroid cartilage provides sites for the attachment of the epiglottis. Epiglottis holds upright during breathing.  

Similarities Between Glottis and Epiglottis 

• Glottis and epiglottis are two anatomical structures, which occur in the larynx. 
• Both are involved in the production of sound. 

Difference Between Glottis and Epiglottis
Definition 

Glottis refers to the part of the larynx which consists of the vocal cords and the slit-like opening between them, affecting the voice modulation through expansion or contraction while epiglottis refers to a flap of cartilage behind the root of the tongue, which is depressed during swallowing to cover the opening of the windpipe.  

Significance 

Glottis is the opening into the windpipe while epiglottis is the superior border of the glottis. 

Determination of the Voice Type 

The size of the glottis is responsible for the voice type while the size of the epiglottis is not responsible for the voice type. 

During Swallowing 

Glottis moves upwards during swallowing while epiglottis moves downwards during swallowing. 

Role 

The glottis is responsible for the production of sounds while the epiglottis prevents food from entering into the larynx. 

Conclusion 

Glottis is the opening into the windpipe, which is responsible for the production of sound. On the other hand, epiglottis is the cartilaginous flap on top of the glottis, which prevents the entering of food into the larynx. The main difference between glottis and epiglottis is the structure and the function. 

Reference: 

1. Bengochea, Kim. “Glottis.” Kenhub, Available Here
2. Bengochea, Kim. “Epiglottis.” Kenhub, Available Here

Image Courtesy:

1. “Glottis2” By Tavin – Own work (CC BY-SA 3.0) via Commons Wikimedia 
2. “Mouth and pharynx” By BruceBlaus. Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – (CC BY 3.0) via Commons Wikimedia