On either side of the laryngeal orifice in humans is a recess, termed the pyriform sinus (also piriform recess, piriform sinus, piriform fossa, or smuggler's fossa), which is bounded medially by the

aryepiglottic fold The aryepiglottic folds are triangular folds of mucous membrane of the larynx. They enclose ligamentous and muscular fibres. They extend from the lateral borders of the epiglottis to the arytenoid cartilages, hence the name 'aryepiglottic'. They ...

, laterally by the

thyroid cartilage The thyroid cartilage is the largest of the nine cartilages that make up the ''laryngeal skeleton'', the cartilage structure in and around the trachea that contains the larynx. It does not completely encircle the larynx (only the cricoid cartilage ...

and

thyrohyoid membrane The thyrohyoid membrane (or hyothyroid membrane) is a broad, fibro-elastic sheet of the larynx. It connects the upper border of the thyroid cartilage to the hyoid bone. Structure The thyrohyoid membrane is attached below to the upper border of ...

. The fossae are involved in speech. The term "pyriform," which means "pear-shaped," is also sometimes spelled "piriform". Deep to the mucous membrane of the pyriform fossa lie the

recurrent laryngeal nerve The recurrent laryngeal nerve (RLN) 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 recurrent laryngeal nerves, right and le ...

as well as the

internal laryngeal nerve The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the inferior ganglion of vagus nerve and in its course receives a branch from the superior cervical ganglion of the sympathetic nervous system. The superio ...

, a branch of the

superior laryngeal nerve The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the inferior ganglion of vagus nerve and in its course receives a branch from the superior cervical ganglion of the sympathetic nervous system. The superi ...

. The internal laryngeal nerve supplies sensation to the area, and it may become damaged if the mucous membrane is inadvertently punctured. Found in laryngopharynx easily The pyriform sinus is a subsite of the

hypopharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...

. This distinction is important for head and neck

cancer staging Cancer staging is the process of determining the extent to which a cancer has developed by growing and spreading. Contemporary practice is to assign a number from I to IV to a cancer, with I being an isolated cancer and IV being a cancer that ha ...

and treatment.AJCC Cancer Staging Handbook: From the AJCC Cancer Staging Manual, Sixth Edition. Ed. Frederick L. Greene, M.D. page 48. The term smuggler's fossa comes from its use for smuggling of small items.

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 Fish bone is any bone of a fish. Fish bone also includes the bony, delicate parts of the skeleton of bony fish, such as ribs and fin rays, but especially the ossification of connective tissue lying transversely inclined backwards to the ribs betwe ...

), 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 tract A fistula (plural: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow or ...

s which are sometimes imprecisely called "

fistula A fistula (plural: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow or ...

s". This can result in acute infectious

thyroiditis Thyroiditis is the inflammation of the thyroid gland. The thyroid gland is located on the front of the neck below the laryngeal prominence, and makes hormones that control metabolism. Signs and symptoms There are many different signs and symptom ...

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