piriform

Piriform is a term meaning pear-shaped, derived from the Latin piriformis meaning “pear-shaped.” In anatomy and related fields, the adjective is used to describe several structures that are roughly pear-shaped.

The piriform cortex is a region of the brain's temporal lobe that constitutes the primary olfactory cortex. It lies in the ventrolateral part of the temporal lobe, around the uncus, and receives olfactory input from the olfactory bulbs. The piriform cortex participates in odor perception and early odor processing and has connections with the amygdala and entorhinal cortex, contributing to olfactory memory and emotional associations.

The piriformis muscle is a small, flat muscle in the gluteal region. It originates from the anterior surface of the sacrum and passes through the greater sciatic foramen to insert on the superior border of the greater trochanter of the femur. Its actions include abduction and lateral rotation of the thigh; it also helps stabilize the hip joint. Variants exist, and the muscle can compress the sciatic nerve, causing piriformis syndrome, characterized by buttock and leg pain.

Piriform recess, also called the piriform fossa, is an anatomical space in the laryngopharynx on each side of the laryngeal inlet. It is bounded by the thyrohyoid membrane, the thyroid cartilage, and the aryepiglottic folds. The recess can harbor aspirated material and is a site of examination in ENT evaluation.