The inferior nasal concha is one of the three paired nasal conchae in the nose. It extends horizontally along the lateral wall of the nasal cavity and consists of a lamina of spongy bone, curled upon itself like a scroll,. The inferior nasal conchae are considered a pair of facial bones. As the air passes through the turbinates, the air is churned against these mucosa-lined bones in order to receive warmth, moisture and cleansing. Superior to inferior nasal concha are the middle nasal concha and superior nasal concha which both arise from the ethmoid bone, of the cranial portion of the skull. Hence, these two are considered as a part of the cranial bones.
In anatomy, a nasal concha, also called a nasal turbinate or turbinal, is a long, narrow, curled shelf of bone that protrudes into the breathing passage of the nose in humans and various animals. The conchae are shaped like an elongated seashell, which gave them their name. A concha is any of the scrolled spongy bones of the nasal passages in vertebrates.
The pyramid-shaped maxillary sinus is the largest of the paranasal sinuses, located in the maxilla. It drains into the middle meatus of the nose through the semilunar hiatus. It is located to the side of the nasal cavity, and below the orbit.
In the ethmoid bone, a sickle shaped projection, the uncinate process, projects posteroinferiorly from the ethmoid labyrinth. Between the posterior edge of this process and the anterior surface of the ethmoid bulla, there is a two-dimensional space, resembling a crescent shape. This space continues laterally as a three-dimensional slit-like space - the ethmoidal infundibulum. This is bounded by the uncinate process, medially, the orbital lamina of ethmoid bone, laterally, and the ethmoidal bulla, posterosuperiorly. This concept is easier to understand if one imagine the infundibulum as a prism so that its medial face is the hiatus semilunaris. The "lateral face" of this infundibulum contains the ostium of the maxillary sinus, which, therefore, opens into the infundibulum.
The agger nasi is a small ridge on the lateral side of the nasal cavity. It is located midway at the anterior edge of the middle nasal concha, directly above the atrium of the middle meatus. It is formed by a mucous membrane that is covering the ethmoidal crest of the maxilla.
The ethmoid sinuses or ethmoid air cells of the ethmoid bone are one of the four paired paranasal sinuses. Unlike the other three pairs of paranasal sinuses which consist of one or two large cavities, the ethmoidal sinuses entail a number of small air-filled cavities. The cells are located within the lateral mass (labyrinth) of each ethmoid bone and are variable in both size and number. The cells are grouped into anterior, middle, and posterior groups; the groups differ in their drainage modalities, though all ultimately drain into either the superior or the middle nasal meatus of the lateral wall of the nasal cavity.
The greater petrosal nerve is a nerve of the head mainly containing pre-ganglionic parasympathetic fibres which ultimately synapse in the pterygopalatine ganglion. It branches from the facial nerve and is derived from the parasympathetic part of the nervus intermedius component of CN VII, with its cell bodies located in the superior salivary nucleus. In the connective tissue substance of the foramen lacerum, the greater petrosal nerve unites with the (sympathetic) deep petrosal nerve to form the nerve of the pterygoid canal which proceeds to the pterygopalatine ganglion.
The semilunar hiatus is a crescent-shaped/semicircular/ curved slit/groove upon the lateral wall of the nasal cavity at the middle nasal meatus 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. It leads into the ethmoidal infundibulum; it marks the medial limit of the ethmoidal infundibulum.
The ethmoidal labyrinth or lateral mass of the ethmoid bone consists of a number of thin-walled cellular cavities, the ethmoid air cells, arranged in three groups, anterior, middle, and posterior, and interposed between two vertical plates of bone; the lateral plate forms part of the orbit, the medial plate forms part of the nasal cavity. In the disarticulated bone many of these cells are opened into, but when the bones are articulated, they are closed in at every part, except where they open into the nasal cavity.
The superior nasal concha is a small, curved plate of bone representing a medial bony process of the labyrinth of the ethmoid bone. The superior nasal concha forms the roof of the superior nasal meatus.
The ethmoid bulla is a rounded elevation upon the lateral wall of the middle nasal meatus produced by one or more of the underlying middle ethmoidal air cells. It varies significantly based on the size of the underlying air cells.
The maxillary hiatus is the opening of a maxillary sinus into the middle nasal meatus of the nasal cavity. It is situated superoposteriorly upon the lateral nasal wall, opening into the nasal cavity at the posterior portion of the ethmoidal infundibulum. Its opening in the maxillary sinus is present upon the superior part of the medial wall of the sinus near the roof of the sinus; because of the position, gravity cannot drain the maxillary sinus contents when the head is erect.
The sphenopalatine foramen is a fissure of the skull that connects the nasal cavity and the pterygopalatine fossa. It gives passage to the sphenopalatine artery, nasopalatine nerve, and the superior nasal nerve.
The subarcuate fossa is a shallow depression upon the internal surface of the petrous part of the temporal bone forming the wall of the posterior cranial fossa. The fossa accommodates the flocculus of the cerebellum. It is situated lateral/posterior to the internal auditory meatus.
The anterior superior alveolar nerve (or anterior superior dental nerve) is a branch of the infraorbital nerve (itself a branch of the maxillary nerve (CN V2)). It passes through the canalis sinuosus to reach and innervate upper front teeth. Through its nasal branch, it also innervates parts of the nasal cavity.
The frontonasal duct is a duct through which either frontal sinus drains into the nasal cavity. Each frontal sinus opens into the frontonasal duct by an opening on the inferomedial part of the floor of the sinus. The frontonasal duct pases inferior-ward to open either into the middle nasal meatus at the anterior end of the ethmoidal infundibulum, or into the anterior ethmoidal air cells.
The perpendicular plate of palatine bone is the vertical part of the palatine bone, and is thin, of an oblong form, and presents two surfaces and four borders.
The ethmoidal infundibulum is a funnel-shaped/slit-like/curved opening/passage/space/cleft upon the anterosuperior portion of the middle nasal meatus at the hiatus semilunaris. The anterior ethmoidal air cells, and (usually) the frontonasal duct open into the ethmoidal infundibulum. The ethmoidal infundibulum extends anterosuperiorly from its opening into the nasal cavity.
The human nose is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones and the nasal cartilages, including the nasal septum which separates the nostrils and divides the nasal cavity into two.
In anatomy, the term nasal meatus can refer to any of the three meatuses (passages) through the skull's nasal cavity: the superior meatus, middle meatus, and inferior meatus.
