The pyriform sinus (also piriform recess, piriform sinus, piriform fossa, or smuggler's fossa) is a small recess on either side of the
laryngeal inlet. It is bounded medially by the
aryepiglottic fold, and laterally by the
thyroid cartilage and
thyrohyoid membrane.
The fossae are involved in speech.
Etymology
The term "pyriform," which means "pear-shaped," is also sometimes spelled "piriform".
The term smuggler's fossa comes from its use for smuggling of small items.
Structure
Relations
Deep to the mucous membrane of the pyriform fossa lie the
recurrent laryngeal nerve
The recurrent laryngeal nerve (RLN), also known as nervus recurrens, is a branch of the vagus nerve ( cranial nerve X) that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recur ...
as well as the
internal laryngeal nerve, a branch of the
superior laryngeal nerve. The internal laryngeal nerve supplies sensation to the area, and it may become damaged if the mucous membrane is inadvertently punctured. The pyriform sinus is a subsite of the
hypopharynx. This distinction is important for head and neck
cancer staging and treatment.
[AJCC Cancer Staging Handbook: From the AJCC Cancer Staging Manual, Sixth Edition. Ed. Frederick L. Greene, M.D. page 48.]
Clinical significance
This sinus is a common place for food particles to become trapped; if foreign material becomes lodged in the piriform fossa of an infant, it may be retrieved nonsurgically. If the area is injured (e.g., by a
fish bone), it can give the sensation of food stuck in the subject's throat.
Remnants of the
pharyngeal pouches III and IV may extent to the piriform sinus as
sinus tracts which are sometimes imprecisely called "
fistula
In anatomy, a fistula (: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") is an abnormal connection (i.e. tube) joining two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other h ...
s".
This can result in acute infectious
thyroiditis which is more common on the left side of the neck.
References
External links
* - "Pharynx: The Laryngopharynx"
{{Authority control
Human head and neck
Human throat
Pharynx