Paranasal sinuses
Paranasal sinuses | |
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Details | |
Identifiers | |
Latin | sinus paranasales |
MeSH | D010256 |
TA98 | A06.1.03.001 |
TA2 | 3176 |
FMA | 59679 |
Anatomical terminology |
Paranasal sinuses are a group of four paired
Structure
Humans possess four pairs of paranasal sinuses, divided into subgroups that are named according to the bones within which the sinuses lie. They are all innervated by branches of the trigeminal nerve (CN V).
- The maxillary sinuses, the largest of the paranasal sinuses, are under the eyes, in the maxillary bones (open in the back of the semilunar hiatus of the nose). They are innervated by the maxillary nerve (CN V2).[2]
- The frontal sinuses, superior to the eyes, in the frontal bone, which forms the hard part of the forehead. They are innervated by the ophthalmic nerve (CN V1).[2]
- The ethmoidal sinuses, which are formed from several discrete air cells within the ethmoid bone between the nose and the eyes. They are innervated by the ethmoidal nerves, which branch from the nasociliary nerve of the ophthalmic nerve (CN V1).
- The sphenoidal sinuses, in the sphenoid bone. They are innervated by the ophthalmic and maxillary nerve (CN V1 and V2).[2]
The paranasal sinuses are lined with respiratory epithelium (ciliated pseudostratified columnar epithelium).
Functions
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One known function of the paranasal sinuses is the production of nitric oxide, which also functions as a facilitator of oxygen uptake.[3]
Development
Paranasal sinuses form developmentally through excavation of bone by air-filled sacs (pneumatic diverticula) from the nasal cavity. This process begins prenatally (intrauterine life), and it continues through the course of an organism's lifetime.
The results of experimental studies suggest that the natural ventilation rate of a sinus with a single
At birth, only the maxillary sinus and the ethmoid sinus are developed but not yet pneumatized; only by the age of seven they are fully aerated. The sphenoid sinus appears at the age of three, and the frontal sinuses first appear at the age of six, and fully develop during adulthood.[5]
CT scans, radiographs (x-ray) and other illustrations
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Coronal CT scan of the paranasal sinuses (soft tissue)
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Coronal CT scan of the paranasal sinuses (bone)
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Paranasal sinuses radiograph (occipitofrontal)
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Paranasal sinuses radiograph (occipitomental)
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Paranasal sinuses radiograph (lateral)
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3D cast of maxillary, frontal, ethmoid and sphenoid sinuses, nasal cavity and hypopharynx.
Clinical significance
Inflammation
The paranasal sinuses are joined to the
These conditions may be treated with drugs such as decongestants, which cause vasoconstriction in the sinuses; reducing inflammation; by traditional techniques of nasal irrigation; or by corticosteroid.[medical citation needed]
Cancer
Malignancies of the paranasal sinuses comprise approximately 0.2% of all malignancies. About 80% of these malignancies arise in the maxillary sinus. Men are much more often affected than women. They most often occur in the age group between 40 and 70 years. Carcinomas are more frequent than sarcomas. Metastases are rare. Tumours of the sphenoid and frontal sinuses are extremely rare.
Etymology
Sinus is a
Other animals
Paranasal sinuses occur in many other animals, including most mammals, birds, non-avian dinosaurs, and crocodilians. The bones occupied by sinuses are quite variable in these other species.
Illustrations
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Paranasal sinuses
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Illustration depicting sinusitis
See also
References
- ^ "Paranasal sinuses". 23 December 2021.
- ^ a b c "Paranasal Sinus Anatomy: Overview, Gross Anatomy, Microscopic Anatomy". 2016-08-24.
- PMID 18951492.
- ^ "ARTICLES | Journal of Applied Physiology". jap.physiology.org. Retrieved 2017-09-07.
- .
- ^ Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 68