meatus

n., pl., -tus·es, or meatus.
A body opening or passage, such as the opening of the ear or the urethral canal.

[Latin meātus, passage, from past participle of meāre, to pass.]

Pl. meatus [L.] an opening or passage.

• acoustic m., m. acusticus, m. auditorius, auditory m. — a passage in the ear; see external acoustic meatus and internal acoustic meatus (below).
• ethmoidal m. — the spaces between the ethmoturbinal bones.
• external acoustic m. — the passageway within the ear between the ear flap and the eardrum.
• internal acoustic m. — the passageway on the medial surface of the petrous temporal bone; transmits the facial and vestibulocochlear nerves.
• m. nasi, m. of nose — one of the three main airways of the nasal cavity which are found on either side of the septum; they are the dorsal, middle and ventral meati.
• nasopharyngeal m. — the common space shared by the right and left nasal cavities just before they enter the nasopharynx.
• m. urinarius, urinary m. — the opening of the urethra on the body surface through which urine is discharged.

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