4
$\begingroup$

The last time I came across this question was when I was in high school. And the explanation I was given is that epiglottis works like a valve, it prevents foods from getting into the windpipe. Still, if I google the majority of the top results agree with this answer. Recently I got interested in rabbit anatomy after I bought a pair as pets. I learned they are "obligate nose breathers due to their epiglottis positioned rostrally to the soft palate". Then I tried to revise my understanding of epiglottis and that let to some sources that claim that epiglottis is not essential for swallowing. For example:

It was at one time thought that the epiglottis acted as " the lid of the larynx"; it was supposed that during deglutition it fell back like a flap over the laryngeal aperture in order to prevent ingress of food or water. This erroneous view as dispelled by Stuart, who proved that during swallowing the epiglottis actually moved forwards, to be squeezed between the base of the tongue and the rest of the larynx. This view cannot be disputed by anyone capable of judging, and the truth of it is borne out when observing a patient whose epiglottis has been almost entirely destroyed by lupus, but whose powers of swallowing remains unaffected.

Negus, VE (1927). "The Function of the Epiglottis". Journal of Anatomy.

Controversy has continued for well over 100 years regarding the role of the epiglottis in deglutition. We describe the effect of isolated epiglottectomy on swallowing success in a case series of 3 adult human subjects with isolated epiglottectomy due to trauma, surgery, or cancerous erosion. The patients were 42, 51, and 70 years of age, and swallowing was analyzed objectively with videofluoroscopy. All subjects exhibited successful swallowing with all food types: thin liquid, puree, and solid food. Specifically, the patient with traumatic epiglottectomy exhibited rapid swallowing success, the patient with surgical epiglottectomy exhibited a short period of dysphagia due to postoperative edema, followed by swallowing success, and the patient with epiglottectomy due to cancerous erosion of the entire epiglottis exhibited long-term adaptation, with successful swallowing maintained. We conclude that the epiglottis is not essential for successful swallowing in humans, because individuals can readily adapt to isolated epiglottectomy and avoid tracheal aspiration.

Leder, Steven B et al. “Epiglottis is not essential for successful swallowing in humans.” The Annals of otology, rhinology, and laryngology vol. 119,12 (2010): 795-8.

Judging from google searches and Wikipedia entry on the topic it seems the dominant view is: epiglottis prevents food from getting into the trachea. But many research like the ones I have mentioned above says that people can swallow without epiglottis. How to make sense of these apparently contradictory claims?

Edit: My question is not the same as the question suggested. The suggested question seeks the function of "hyoepiglottic ligament" which is a ligament that connects epiglottis "to the upper border of the body of the hyoid bone". My question is related to the function of epiglottis itself in the background of contradictory claims found in the literature.

$\endgroup$
  • 1
    $\begingroup$ @tyersome No it doesn't. I have added the reason in the OP. $\endgroup$ – Ahmed Abdullah May 21 at 15:55
  • 1
    $\begingroup$ @tyersome As the user who asked the question you proposed as dupe, I can say that this post is clearly asking a different question and should not be closed. (this is akin to comparing the function of the knee and the funciton of the MCL ligament or to comparing the function of the lungs vs the function of the trachea) $\endgroup$ – theforestecologist May 22 at 18:10
  • 1
    $\begingroup$ AhmedAbdullah and @theforestecologist — Ok, close vote withdrawn. $\endgroup$ – tyersome May 25 at 4:07
2
$\begingroup$

You are right, The main function of the epiglottis is to seal off the windpipe during eating, so that food is not accidentally inhaled.(quote from here).

It's a flat shield of cartilage, which is obviously an efficient valve, It's a valve between the trachea and the esophagus.

It lets lions to eat a pound of meat without choking on their prey. It lets humans drink tea without coughing on their buddies.

Information stating that it's "possible" to eat without an epiglottis doesn't imply that it's "efficient and safe", and contradicts medical interventions where they use a piece of ear cartilage to build a new epiglottis.

Survival didn't encourage the "possibility to eat"... it has made animals very robust and efficient at it. Herbivores can spend most of their day eating, and are often attacked while they are eating and drinking. Carnivores also have reasons for efficient swallowing, big carnivores can eat many pounds of meat very fast while fending off competition from hyenas and other predators.

Sleep apnea patients have their epiglottis modified to give room to breathe at night, and they risk choking and aspiration for a while, although they can adapt because they keep some of the cartilage, so they still have a valve.

Different animals have different breathing habits, with some being obligate nose breathers, including human babies of under 6 months and up to 6 years. That's because the epiglottis either contacts the trachea or it leaves space there.

enter image description here

| improve this answer | |
$\endgroup$
  • 2
    $\begingroup$ I would strongly advise refraining from using healthline.com as a source of "reputable" information (read here). Healthline.com competes with equally non-reputable WebMD and is associated with additional non-reputable medical websites such as Yahoo! Health and DoctorOz.com. --------- More reputable sources could include the CDC, medlineplus.gov, mayoclinic.org, or actually reporting from primary literature (try searching PubMed). $\endgroup$ – theforestecologist May 22 at 18:19
  • 1
    $\begingroup$ You also make a number of claims throughout your post that are not supported (e.g., ear cartilage procedures, feeding efficiency of animals, sleep apnea patients and adaptation to treatments, and breathing habits). Please update your post with support for these claims. Thanks! $\endgroup$ – theforestecologist May 22 at 18:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.