Hiatus semilunaris
Encyclopedia
The hiatus semilunaris is a crescent-shaped groove in the lateral wall of the nasal cavity
just inferior to the ethmoidal bulla. It is the location of the openings for the frontal sinus
, maxillary sinus
, and anterior ethmoidal sinus. It is bounded inferiorly and anteriorly by the sharp concave margin of the uncinate process of the ethmoid bone, superiorly by the ethmoidal bulla, and posteriorly by the ethmoidal process of the inferior nasal concha.
, which drains the frontal sinus
.
The anterior ethmoidal cells of the ethmoidal sinus open into the front part of the infundibulum as well. In slightly over 50% of subjects, this is directly continuous with the frontonasal duct from the frontal air sinus. When the anterior end of the uncinate process fuses with the front part of the bulla, however, this continuity is interrupted and the frontonasal duct then drains directly into the anterior end of the middle meatus
.
The ostium for the maxillary sinus
opens posteriorly in this groove and is the largest ostium within the semilunar hiatus.
Nasal cavity
The nasal cavity is a large air filled space above and behind the nose in the middle of the face.- Function :The nasal cavity conditions the air to be received by the other areas of the respiratory tract...
just inferior to the ethmoidal bulla. It is the location of the openings for the frontal sinus
Frontal sinus
Sinuses are mucosa-lined airspaces within the bones of the face and skull. The frontal sinuses, situated behind the superciliary arches, are absent at birth, but are generally fairly well developed between the seventh and eighth years, only reaching their full size after puberty...
, maxillary sinus
Maxillary sinus
The pyramid shaped maxillary sinus is the largest of the paranasal sinuses, and drains into the nose. It is present at birth as rudimentary air cells, and develops throughout childhood.-General characteristics:...
, and anterior ethmoidal sinus. It is bounded inferiorly and anteriorly by the sharp concave margin of the uncinate process of the ethmoid bone, superiorly by the ethmoidal bulla, and posteriorly by the ethmoidal process of the inferior nasal concha.
Sinus Drainage
Following the curve anteriorly leads into the infundibulum of the frontonasal ductFrontonasal duct
The frontal air sinuses are lined by mucous membrane, and each communicates with the corresponding nasal cavity by means of a passage called the frontonasal duct....
, which drains the frontal sinus
Frontal sinus
Sinuses are mucosa-lined airspaces within the bones of the face and skull. The frontal sinuses, situated behind the superciliary arches, are absent at birth, but are generally fairly well developed between the seventh and eighth years, only reaching their full size after puberty...
.
The anterior ethmoidal cells of the ethmoidal sinus open into the front part of the infundibulum as well. In slightly over 50% of subjects, this is directly continuous with the frontonasal duct from the frontal air sinus. When the anterior end of the uncinate process fuses with the front part of the bulla, however, this continuity is interrupted and the frontonasal duct then drains directly into the anterior end of the middle meatus
Middle meatus
The middle meatus is a nasal opening or canal situated between the middle and inferior conchæ, and extends from the anterior to the posterior end of the latter....
.
The ostium for the maxillary sinus
Maxillary sinus
The pyramid shaped maxillary sinus is the largest of the paranasal sinuses, and drains into the nose. It is present at birth as rudimentary air cells, and develops throughout childhood.-General characteristics:...
opens posteriorly in this groove and is the largest ostium within the semilunar hiatus.