Pyriform sinus is laterally bounded by what?
On either side of the laryngeal orifice in humans is a recess, termed the piriform sinus (also piriformrecess, pyriform sinus, piriform fossa, or smuggler's fossa), which is bounded medially by the aryepiglottic fold, laterally by the thyroid cailage and thyrohyoid membrane. The fossae are involved in speech.
Interarytenoid aery
Thyroid aery
Epiglottis
Thyrohyoid membrane