meatus
(mē-āt'ŭs 
)
Plural: meatus
[L meatus, a going, passage, path.]
A passageway or an opening.
meatal,
(mē-āt'ăl )
acoustic m.Either the external or internal acoustic (auditory) canal or opening.
m. acusticus externus External auditory canal.
m. acusticus internus Internal auditory canal.
external acoustic m.External auditory meatus.
external auditory m.The outer opening of the external auditory canal, or the canal itself.
SEE: external acoustic meatus; external auditory foramen.
inferior nasal meatus Meatus nasi inferior.
internal acoustic m.Internal auditory meatus.
internal auditory m.The opening of the internal auditory canal into the cranial cavity located on the posterior surface of the petrous portion of the temporal bone, or the canal itself. SYN: internal acoustic meatus.
m. nasi communis The common nasal cavity on either side of septum, into which three meatus open.
m. nasi inferior The space beneath inferior turbinate or concha of the nasal cavity into which the lacrimal canal opens. SYN: inferior nasal meatus.
m. nasi medius The space beneath middle turbinate or concha of the nasal cavity into which the frontonsal canal, the anterior and middle posterior ehtmoidal air cells and the maxillary sinus drain. It is the location of the ethmoid bulla under which the semilunar hiatus lies. SYN: middle meatus.
m. nasi superior The space beneath superior turbinate or concha of the nasal cavity into which the posterior ethmoid air cells drain.
m. nasopharyngeus The posterior portion of nasal cavity, which communicates with the nasopharynx.
pinhole m.Stricture of the urethra.
urethral m.The external opening of the urethra. SYN: urinary meatus; meatus urinarius.