Nasal concha 534130 223943529 2008-07-06T17:03:50Z AlexandriNo 1640494 {{Infobox Anatomy | Name = {{PAGENAME}} | Latin = conchae nasales | GraySubject = | GrayPage = | Image = Gray153.png | Caption = Lateral wall of nasal cavity, showing [[ethmoid bone]] in position. (Superior and middle in pink, and inferior in blue.) | Image2 = Illu_nose_nasal_cavities.jpg | Caption2 = | Width = 260 | System = | MeshName = Conchae+Nasales | MeshNumber = A02.835.232.781.324.948 | DorlandsPre = t_23 | DorlandsSuf = 12832600 | }} In [[anatomy]], a '''turbinate''' (or '''nasal concha''') is a long, narrow and curled bone shelf (shaped like an elongated sea-shell) which protrudes into the breathing passage of the [[nose]]. Turbinate bone refers to any of the scrolled spongy [[bone]]s of the [[Nasal Cavity|nasal passages]] in [[human]]s and other [[vertebrates]]. <ref name="Gray">[http://www.bartelby.com/107/223.html ''Anatomy of the Human Body''] Gray, Henry (1918) The Nasal Cavity.</ref> In humans, the turbinates divide the nasal airway into three groove-like air passages –and are responsible for forcing inhaled air to flow in a steady, regular pattern around the largest possible surface of [[cilia]] and climate controlling tissue. ==Structure and functions of turbinates== Turbinates are composed of [[pseudostratified epithelium|pseudostratified]] [[Columnar epithelia|columnar]], [[ciliated]] [[respiratory epithelium]] with a thick, [[Blood vessel|vascular]] and erectile [[glandular]] tissue layer. <ref name="Reddy">[http://www.utmb.edu/otoref/grnds/Turbinate-2003-0312/Turbinate-2003-0312.htm Turbinate Dysfunction: Focus on the role of the inferior turbinates in nasal airway obstruction.] S.S. Reddy, et al. ''Grand Rounds Presentation, UTMB, Dept. of Otolaryngology''</ref> The turbinates are located laterally in the nasal cavities, curling [[Human Anatomical Terms#Anatomical_directions|medial]]ly and downwards into the nasal airway. Each pair is composed of one turbinate in either side of the nasal cavity, divided by the [[Nasal septum|septum]].<ref name="Reddy"/> The ''[[Inferior nasal conchae|inferior turbinates]]'' are the largest turbinates, and can be as long as the [[index finger]], and are responsible for the majority of airflow direction, humidification, heating, and filtering of air inhaled through the nose.<ref name="Gray"/> The ''[[Middle nasal concha|middle turbinates]]'' are smaller, usually as long as the [[little finger]]. They project downwards over the openings of the [[maxillary]] and [[ethmoid]] sinuses, and act as buffers to protect the sinuses from coming in direct contact with pressurized nasal airflow. Most inhaled airflow travels between the inferior turbinate and the middle turbinate.<ref name="Gray"/> The ''[[Superior nasal concha|superior turbinates]]'' are smaller structures, connected to the middle turbinates by nerve-endings, and serve to protect the [[olfactory bulb]].<ref name="Gray"/> ===Role of turbinates in the respiratory system=== The turbinates compose most of the [[mucosal]] tissue of the [[nose]] and are required for functional [[respiratory system|respiration]]. The turbinates are enriched with airflow pressure and temperature sensing nerve receptors (linked to the “[[trigeminal]]” nerve route, the [[fifth cranial nerve]]), allowing for tremendous erectile capabilities of [[nasal congestion]] and decongestion (very much like the [[penis]]), in response to the [[climatic]] conditions and changing needs of the body.<ref name="Reddy"/> The turbinates are also responsible for [[filter (air)|filtration]], heating and humidification of air inhaled through the nose. Of these three, filtration is the most important reason to breathe through the nose.{{Fact|date=September 2007}} As air passes over the turbinate tissues it is heated to body temperature, humidified (up to 98% [[dew point|water saturation]]) and filtered.<ref name="Reddy"/> ===Role of turbinates as an immunological defense=== The [[respiratory epithelium]] which covers the erectile tissue (or [[Lamina propria]]) of the turbinates plays a major role in the body’s first line of [[immunological]] defense. The respiratory epithelium is partially composed of [[mucus]] producing [[goblet cells]]. This secreted mucus covers the nasal cavities, and serves as a filter, by trapping air-borne particles larger than 2 to 3 [[micrometers]]. The respiratory epithelium also serves as a means of access for the [[lymphatic system]] which protects the body from being infected by viruses or bacteria.<ref name="Gray"/> ===Role of turbinates in olfaction=== The turbinates provide, first and foremost, the humidity needed to preserve the delicate olfactory (smell) [[epithelium]] needed to keep the olfactory receptors healthy and alert. If the epithelial layer gets dry or irritated, it may cease to function. This is usually a temporary condition, but over time, may lead to chronic [[anosmia]]<ref name="Reddy"/>. The turbinates also increase the [[surface area]] of the inside of the nose, and by directing and deflecting airflow across the maximum mucosal surface of the inner nose, they are able to propel the inspired air. This, coupled with the humidity and filtration provided by the turbinates, helps to carry more scent molecules towards the higher, and very narrow regions of the nasal airways, where olfaction nerve receptors are located<ref name="Gray"/>. The superior turbinates literally hood-over, and protect the nerve axons piercing through the [[cribriform plate]] (a porous bone plate that separates the nose from the brain) into the nose. Some areas of the middle turbinates are also [[innervate]]d by the olfactory bulb. All three turbinates are innervated by [[pain]] and temperature receptors, via the [[trigeminal nerve]] (or, the fifth [[cranial nerve]])<ref name="Reddy"/>. Research has shown that there is a strong connection between these nerve endings and activation of the olfactory receptors, but science has yet to fully explain this interaction. ==Turbinate dysfunction== Large, swollen turbinates may lead to blockage of nasal breathing. [[Allergies]], exposure to environmental [[irritant]]s, or a persistent [[inflammation]] within the sinuses, can lead to turbinate swelling. Deformity of the nasal [[septum]] can also result in enlarged turbinates. <ref name="SIC"> [http://www.sinusinfocenter.com/treatment_inferiorTurbinate.html Reduction/Removal of the Inferior Turbinate] From the Sinus Info Center.</ref> Treatment of the underlying allergy or irritant may reduce turbinate swelling. In cases that do not resolve, or for treatment of [[deviated septum]], turbinate reduction surgery may be required. Bipolar radiofrequency ablation, a technique used for [[coblation tonsillectomy]], is also used for the treatment of Generally, because the turbinates are essential for respiration, only small amounts of turbinate tissue are removed. Extensive reduction of the inferior or middle turbinates can cause [[empty nose syndrome]].<ref name="SIC"/> == See also == *[[Bone#Terminology|Bone terminology]] *[[Anatomical terms of location]] *[[Superior nasal concha]], [[middle nasal concha]] and [[inferior nasal concha]] *[[Empty nose syndrome]] ==Additional images== <gallery> Image:Concha nasalis.gif|Nasal conchae: Blocked/free Image:NormalNose-CT-Front-cross-section-common-wiki.jpg|Normal Nose CT Front cross section Image:Gray859.png|Coronal section of nasal cavities. Image:Right-nasal-airway-passage.jpg|Right nasal airway passage </gallery> ==References== <references/> {{Head and neck general}} [[Category:Skeletal system]] [[Category:Olfaction]] [[et:Koaanid]] [[fr:Cornet nasal]] [[he:קונכיות האף]] [[it:Turbinati]] [[ja:鼻甲介]] [[nl:Neusschelp]] [[pt:Concha nasal]]