Nasal Cavity: The proximal portion of the respiratory passages on either side of the NASAL SEPTUM. Nasal cavities, extending from the nares to the NASOPHARYNX, are lined with ciliated NASAL MUCOSA.Nose Neoplasms: Tumors or cancer of the NOSE.Nasal Mucosa: The mucous lining of the NASAL CAVITY, including lining of the nostril (vestibule) and the OLFACTORY MUCOSA. Nasal mucosa consists of ciliated cells, GOBLET CELLS, brush cells, small granule cells, basal cells (STEM CELLS) and glands containing both mucous and serous cells.Nasal Septum: The partition separating the two NASAL CAVITIES in the midplane. It is formed by the SEPTAL NASAL CARTILAGE, parts of skull bones (ETHMOID BONE; VOMER), and membranous parts.Rhinometry, Acoustic: Diagnostic measurement of the nose and its cavity through acoustic reflections. Used to measure nasal anatomical landmarks, nasal septal deviation, and nasal airway changes in response to allergen provocation tests (NASAL PROVOCATION TESTS).Nose Diseases: Disorders of the nose, general or unspecified.Turbinates: The scroll-like bony plates with curved margins on the lateral wall of the NASAL CAVITY. Turbinates, also called nasal concha, increase the surface area of nasal cavity thus providing a mechanism for rapid warming and humidification of air as it passes to the lung.Paranasal Sinus Neoplasms: Tumors or cancer of the PARANASAL SINUSES.Paranasal Sinuses: Air-filled spaces located within the bones around the NASAL CAVITY. They are extensions of the nasal cavity and lined by the ciliated NASAL MUCOSA. Each sinus is named for the cranial bone in which it is located, such as the ETHMOID SINUS; the FRONTAL SINUS; the MAXILLARY SINUS; and the SPHENOID SINUS.Nose: A part of the upper respiratory tract. It contains the organ of SMELL. The term includes the external nose, the nasal cavity, and the PARANASAL SINUSES.Nasal Polyps: Focal accumulations of EDEMA fluid in the NASAL MUCOSA accompanied by HYPERPLASIA of the associated submucosal connective tissue. Polyps may be NEOPLASMS, foci of INFLAMMATION, degenerative lesions, or malformations.Nasal Obstruction: Any hindrance to the passage of air into and out of the nose. The obstruction may be unilateral or bilateral, and may involve any part of the NASAL CAVITY.Olfactory Mucosa: That portion of the nasal mucosa containing the sensory nerve endings for SMELL, located at the dome of each NASAL CAVITY. The yellow-brownish olfactory epithelium consists of OLFACTORY RECEPTOR NEURONS; brush cells; STEM CELLS; and the associated olfactory glands.Nasal Lavage Fluid: Fluid obtained by THERAPEUTIC IRRIGATION or washout of the nasal cavity and NASAL MUCOSA. The resulting fluid is used in cytologic and immunologic assays of the nasal mucosa such as with the NASAL PROVOCATION TEST in the diagnosis of nasal hypersensitivity.Administration, Intranasal: Delivery of medications through the nasal mucosa.Nasal Decongestants: Drugs designed to treat inflammation of the nasal passages, generally the result of an infection (more often than not the common cold) or an allergy related condition, e.g., hay fever. The inflammation involves swelling of the mucous membrane that lines the nasal passages and results in inordinate mucus production. The primary class of nasal decongestants are vasoconstrictor agents. (From PharmAssist, The Family Guide to Health and Medicine, 1993)Nasal Sprays: Pharmacologic agents delivered into the nostrils in the form of a mist or spray.Ethmoid Sinus: The numerous (6-12) small thin-walled spaces or air cells in the ETHMOID BONE located between the eyes. These air cells form an ethmoidal labyrinth.Epistaxis: Bleeding from the nose.Esthesioneuroblastoma, Olfactory: A malignant olfactory neuroblastoma arising from the olfactory epithelium of the superior nasal cavity and cribriform plate. It is uncommon (3% of nasal tumors) and rarely is associated with the production of excess hormones (e.g., SIADH, Cushing Syndrome). It has a high propensity for multiple local recurrences and bony metastases. (From Holland et al., Cancer Medicine, 3rd ed, p1245; J Laryngol Otol 1998 Jul;112(7):628-33)Maxillary Sinus: The air space located in the body of the MAXILLARY BONE near each cheek. Each maxillary sinus communicates with the middle passage (meatus) of the NASAL CAVITY on the same side.Granuloma, Pyogenic: A disorder of the skin, the oral mucosa, and the gingiva, that usually presents as a solitary polypoid capillary hemangioma often resulting from trauma. It is manifested as an inflammatory response with similar characteristics to those of a granuloma.Maxillary Sinus Neoplasms: Tumors or cancer of the MAXILLARY SINUS. They represent the majority of paranasal neoplasms.Rhinitis: Inflammation of the NASAL MUCOSA, the mucous membrane lining the NASAL CAVITIES.Rhinitis, Atrophic: A chronic inflammation in which the NASAL MUCOSA gradually changes from a functional to a non-functional lining without mucociliary clearance. It is often accompanied by degradation of the bony TURBINATES, and the foul-smelling mucus which forms a greenish crust (ozena).Ethmoid Bone: A light and spongy (pneumatized) bone that lies between the orbital part of FRONTAL BONE and the anterior of SPHENOID BONE. Ethmoid bone separates the ORBIT from the ETHMOID SINUS. It consists of a horizontal plate, a perpendicular plate, and two lateral labyrinths.Paranasal Sinus Diseases: Diseases affecting or involving the PARANASAL SINUSES and generally manifesting as inflammation, abscesses, cysts, or tumors.Olfactory Nerve: The 1st cranial nerve. The olfactory nerve conveys the sense of smell. It is formed by the axons of OLFACTORY RECEPTOR NEURONS which project from the olfactory epithelium (in the nasal epithelium) to the OLFACTORY BULB.Nasal Bone: Either one of the two small elongated rectangular bones that together form the bridge of the nose.Rhinomanometry: Technique for measuring air pressure and the rate of airflow in the nasal cavity during respiration.Endoscopy: Procedures of applying ENDOSCOPES for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. transluminal, to examine or perform surgery on the interior parts of the body.Sinusitis: Inflammation of the NASAL MUCOSA in one or more of the PARANASAL SINUSES.Models, Anatomic: Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.Peritoneal Cavity: The space enclosed by the peritoneum. It is divided into two portions, the greater sac and the lesser sac or omental bursa, which lies behind the STOMACH. The two sacs are connected by the foramen of Winslow, or epiploic foramen.Pasteurella Infections: Infections with bacteria of the genus PASTEURELLA.Mouth: The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.Rhinoscleroma: A granulomatous disease caused by KLEBSIELLA RHINOSCLEROMATIS infection. Despite its name, this disease is not limited to the nose and NASOPHARYNX but may affect any part of the RESPIRATORY TRACT, sometimes with extension to the lip and the skin.Papilloma, Inverted: A mucosal tumor of the urinary bladder or nasal cavity in which proliferating epithelium is invaginated beneath the surface and is more smoothly rounded than in other papillomas. (Stedman, 25th ed)Nitrosamines: A class of compounds that contain a -NH2 and a -NO radical. Many members of this group have carcinogenic and mutagenic properties.Vomeronasal Organ: An accessory chemoreceptor organ that is separated from the main OLFACTORY MUCOSA. It is situated at the base of nasal septum close to the VOMER and NASAL BONES. It forwards chemical signals (such as PHEROMONES) to the CENTRAL NERVOUS SYSTEM, thus influencing reproductive and social behavior. In humans, most of its structures except the vomeronasal duct undergo regression after birth.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Histology, Comparative: The study of the similarities and differences in the structures of homologous tissues across various species.Angiomyoma: A benign tumor consisting of vascular and smooth muscle elements.Bordetella bronchiseptica: A species of BORDETELLA that is parasitic and pathogenic. It is found in the respiratory tract of domestic and wild mammalian animals and can be transmitted from animals to man. It is a common cause of bronchopneumonia in lower animals.Rhinitis, Allergic, Perennial: Inflammation of the mucous membrane of the nose similar to that found in hay fever except that symptoms persist throughout the year. The causes are usually air-borne allergens, particularly dusts, feathers, molds, animal fur, etc.Angiofibroma: A benign neoplasm of fibrous tissue in which there are numerous small and large, frequently dilated, vascular channels. (Stedman, 25th ed)Smell: The ability to detect scents or odors, such as the function of OLFACTORY RECEPTOR NEURONS.Tampons, Surgical: Plugs or cylinders made of cotton, sponge, or other absorbent material. They are used in surgery to absorb fluids such as blood or drainage.Bordetella Infections: Infections with bacteria of the genus BORDETELLA.Respiratory System: The tubular and cavernous organs and structures, by means of which pulmonary ventilation and gas exchange between ambient air and the blood are brought about.Nose Deformities, Acquired: Abnormalities of the nose acquired after birth from injury or disease.Nasal Cartilages: Hyaline cartilages in the nose. There are five major nasal cartilages including two lateral, two alar, and one septal.Anatomy, Comparative: The comparative study of animal structure with regard to homologous organs or parts. (Stedman, 25th ed)Olfactory Bulb: Ovoid body resting on the CRIBRIFORM PLATE of the ethmoid bone where the OLFACTORY NERVE terminates. The olfactory bulb contains several types of nerve cells including the mitral cells, on whose DENDRITES the olfactory nerve synapses, forming the olfactory glomeruli. The accessory olfactory bulb, which receives the projection from the VOMERONASAL ORGAN via the vomeronasal nerve, is also included here.Decalcification Technique: Removal of minerals from bones during bone examination.Otorhinolaryngologic Surgical Procedures: Surgery performed on the ear and its parts, the nose and nasal cavity, or the throat, including surgery of the adenoids, tonsils, pharynx, and trachea.Nasopharynx: The top portion of the pharynx situated posterior to the nose and superior to the SOFT PALATE. The nasopharynx is the posterior extension of the nasal cavities and has a respiratory function.Hemangiopericytoma: A tumor composed of spindle cells with a rich vascular network, which apparently arises from pericytes, cells of smooth muscle origin that lie around small vessels. Benign and malignant hemangiopericytomas exist, and the rarity of these lesions has led to considerable confusion in distinguishing between benign and malignant variants. (From Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1364)Olfactory Marker Protein: A ubiquitous, cytoplasmic protein found in mature OLFACTORY RECEPTOR NEURONS of all VERTEBRATES. It is a modulator of the olfactory SIGNAL TRANSDUCTION PATHWAY.Airway Resistance: Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Frontal Sinus: One of the paired, but seldom symmetrical, air spaces located between the inner and outer compact layers of the FRONTAL BONE in the forehead.Palatal Expansion Technique: An orthodontic method used for correcting narrow or collapsed maxillary arches and functional cross-bite. (From Jablonski's Dictionary of Dentistry),Nasopharyngeal Neoplasms: Tumors or cancer of the NASOPHARYNX.Hydrocarbons, IodinatedAir Movements: The motion of air currents.Myiasis: The invasion of living tissues of man and other mammals by dipterous larvae.Olfactory Nerve Injuries: Traumatic injuries to the OLFACTORY NERVE. It may result in various olfactory dysfunction including a complete loss of smell.Pasteurella multocida: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria normally found in the flora of the mouth and respiratory tract of animals and birds. It causes shipping fever (see PASTEURELLOSIS, PNEUMONIC); HEMORRHAGIC BACTEREMIA; and intestinal disease in animals. In humans, disease usually arises from a wound infection following a bite or scratch from domesticated animals.Dental Cavity Preparation: An operation in which carious material is removed from teeth and biomechanically correct forms are established in the teeth to receive and retain restorations. A constant requirement is provision for prevention of failure of the restoration through recurrence of decay or inadequate resistance to applied stresses. (Boucher's Clinical Dental Terminology, 4th ed, p239-40)Respiratory Tract NeoplasmsCoronavirus, Rat: A species of CORONAVIRUS causing pneumonia in newborn rats but a clinically inapparent infection in adults. It is separate but antigenically related to MURINE HEPATITIS VIRUS.Methylmethacrylate: The methyl ester of methacrylic acid. It polymerizes easily to form POLYMETHYL METHACRYLATE. It is used as a bone cement.Dacryocystorhinostomy: Surgical fistulization of the LACRIMAL SAC for external drainage of an obstructed nasolacrimal duct.Rats, Inbred F344Odors: The volatile portions of substances perceptible by the sense of smell. (Grant & Hackh's Chemical Dictionary, 5th ed)Olfactory Receptor Neurons: Neurons in the OLFACTORY EPITHELIUM with proteins (RECEPTORS, ODORANT) that bind, and thus detect, odorants. These neurons send their DENDRITES to the surface of the epithelium with the odorant receptors residing in the apical non-motile cilia. Their unmyelinated AXONS synapse in the OLFACTORY BULB of the BRAIN.Pleural Cavity: Paired but separate cavity within the THORACIC CAVITY. It consists of the space between the parietal and visceral PLEURA and normally contains a capillary layer of serous fluid that lubricates the pleural surfaces.Pasteurella: The oldest recognized genus of the family PASTEURELLACEAE. It consists of several species. Its organisms occur most frequently as coccobacillus or rod-shaped and are gram-negative, nonmotile, facultative anaerobes. Species of this genus are found in both animals and humans.Administration, Inhalation: The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.Nasal Surgical Procedures: Surgical operations on the nose and nasal cavity.Olfactory Pathways: Set of nerve fibers conducting impulses from olfactory receptors to the cerebral cortex. It includes the OLFACTORY NERVE; OLFACTORY BULB; OLFACTORY TRACT; OLFACTORY TUBERCLE; ANTERIOR PERFORATED SUBSTANCE; and OLFACTORY CORTEX.Orbit: Bony cavity that holds the eyeball and its associated tissues and appendages.Maxillary Artery: A branch of the external carotid artery which distributes to the deep structures of the face (internal maxillary) and to the side of the face and nose (external maxillary).Nasal Lavage: Irrigation of the nose with saline or irrigation solutions for diagnostic or therapeutic purposes. It is used to remove irritants, allergens, or microorganisms from the nose.Rodent Diseases: Diseases of rodents of the order RODENTIA. This term includes diseases of Sciuridae (squirrels), Geomyidae (gophers), Heteromyidae (pouched mice), Castoridae (beavers), Cricetidae (rats and mice), Muridae (Old World rats and mice), Erethizontidae (porcupines), and Caviidae (guinea pigs).Pulmonary Ventilation: The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.Wood: A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.Nasal Provocation Tests: Application of allergens to the nasal mucosa. Interpretation includes observation of nasal symptoms, rhinoscopy, and rhinomanometry. Nasal provocation tests are used in the diagnosis of nasal hypersensitivity, including RHINITIS, ALLERGIC, SEASONAL.Papilloma: A circumscribed benign epithelial tumor projecting from the surrounding surface; more precisely, a benign epithelial neoplasm consisting of villous or arborescent outgrowths of fibrovascular stroma covered by neoplastic cells. (Stedman, 25th ed)Hamartoma: A focal malformation resembling a neoplasm, composed of an overgrowth of mature cells and tissues that normally occur in the affected area.Lymphoma, Extranodal NK-T-Cell: An extranodal neoplasm, usually possessing an NK-cell phenotype and associated with EPSTEIN-BARR VIRUS. These lymphomas exhibit a broad morphologic spectrum, frequent necrosis, angioinvasion, and most commonly present in the midfacial region, but also in other extranodal sites.Inhalation: The act of BREATHING in.Epithelium: One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.Lacrimal Duct Obstruction: Interference with the secretion of tears by the lacrimal glands. Obstruction of the LACRIMAL SAC or NASOLACRIMAL DUCT causing acute or chronic inflammation of the lacrimal sac (DACRYOCYSTITIS). It is caused also in infants by failure of the nasolacrimal duct to open into the inferior meatus and occurs about the third week of life. In adults occlusion may occur spontaneously or after injury or nasal disease. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p250)Palatal Neoplasms: Tumors or cancer of the PALATE, including those of the hard palate, soft palate and UVULA.Tracheal NeoplasmsMaxillary Neoplasms: Cancer or tumors of the MAXILLA or upper jaw.Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Carcinogens: Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.Skull Base: The inferior region of the skull consisting of an internal (cerebral), and an external (basilar) surface.Irritants: Drugs that act locally on cutaneous or mucosal surfaces to produce inflammation; those that cause redness due to hyperemia are rubefacients; those that raise blisters are vesicants and those that penetrate sebaceous glands and cause abscesses are pustulants; tear gases and mustard gases are also irritants.Swine Diseases: Diseases of domestic swine and of the wild boar of the genus Sus.Marsupialia: An infraclass of MAMMALS, also called Metatheria, where the young are born at an early stage of development and continue to develop in a pouch (marsupium). In contrast to Eutheria (placentals), marsupials have an incomplete PLACENTA.Adenoma, Pleomorphic: A benign, slow-growing tumor, most commonly of the salivary gland, occurring as a small, painless, firm nodule, usually of the parotid gland, but also found in any major or accessory salivary gland anywhere in the oral cavity. It is most often seen in women in the fifth decade. Histologically, the tumor presents a variety of cells: cuboidal, columnar, and squamous cells, showing all forms of epithelial growth. (Dorland, 27th ed)Rhinoplasty: A plastic surgical operation on the nose, either reconstructive, restorative, or cosmetic. (Dorland, 28th ed)Trigeminal Nerve: The 5th and largest cranial nerve. The trigeminal nerve is a mixed motor and sensory nerve. The larger sensory part forms the ophthalmic, mandibular, and maxillary nerves which carry afferents sensitive to external or internal stimuli from the skin, muscles, and joints of the face and mouth and from the teeth. Most of these fibers originate from cells of the TRIGEMINAL GANGLION and project to the TRIGEMINAL NUCLEUS of the brain stem. The smaller motor part arises from the brain stem trigeminal motor nucleus and innervates the muscles of mastication.Formaldehyde: A highly reactive aldehyde gas formed by oxidation or incomplete combustion of hydrocarbons. In solution, it has a wide range of uses: in the manufacture of resins and textiles, as a disinfectant, and as a laboratory fixative or preservative. Formaldehyde solution (formalin) is considered a hazardous compound, and its vapor toxic. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p717)Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Exocrine Glands: Glands of external secretion that release its secretions to the body's cavities, organs, or surface, through a duct.Lithiasis: A condition characterized by the formation of CALCULI and concretions in the hollow organs or ducts of the body. They occur most often in the gallbladder, kidney, and lower urinary tract.Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.