"from the chamber of the middle ear to the back of the nasopharynx. Normally, the Eustachian tube is collapsed, but it gapes open both with swallowing and with positive pressure. When taking off in an airplane, the surrounding air pressure goes from higher (on the ground) to lower (in the sky). The air in the middle ear expands as the plane gains altitude, and pushes its way into the back of the nose and mouth. On the way down, the volume of air in the middle ear shrinks, and a slight vacuum is produced. ""Active"" opening of the Eustachian tube"
"Eustachian tube The Eustachian tube, also known as the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear. It is a part of the middle ear. In adult humans the Eustachian tube is approximately long and in diameter. It is named after the sixteenth-century Italian anatomist Bartolomeo Eustachi. In humans and other land animals the middle ear (like the ear canal) is normally filled with air. Unlike the open ear canal, however, the air of the middle ear is not in direct contact with the atmosphere outside the body. The Eustachian tube connects"
"is damaged. Epistaxis (nosebleed) is a very common presentation to veterinary surgeons and this may often be fatal unless a balloon catheter can be placed in time to suppress bleeding. Eustachian tube The Eustachian tube, also known as the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear. It is a part of the middle ear. In adult humans the Eustachian tube is approximately long and in diameter. It is named after the sixteenth-century Italian anatomist Bartolomeo Eustachi. In humans and other land animals the middle ear (like the ear canal) is normally"
"Tympanostomy tube Tympanostomy tube, also known as a grommet or myringotomy tube, is a small tube inserted into the eardrum in order to keep the middle ear aerated for a prolonged period of time, and to prevent the accumulation of fluid in the middle ear. The operation to insert the tube involves a myringotomy and is performed under local or general anesthesia. The tube itself is made in a variety of designs. The most commonly used type is shaped like a grommet. When it is necessary to keep the middle ear ventilated for a very long period, a ""T""-shaped tube"
"or tube), the infant is fitted with a blunt-tipped length of surgical tubing (or an endotracheal tube fitted to the child), which is placed under direct visualization with a laryngoscope, being inserted into the nose and down the pharynx (or throat), ending just above the vocal cords. Surgical threads fitted through holes in the outside end of the tube are attached to the cheek with a special skin-like adhesive material called 'stomahesive', which is also wrapped around the outside end of the tube (but not over the opening at the end) to keep the tube in place. This tube or"
"Pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity and above the esophagus and larynx, or the tubes going down to the stomach and the lungs. It is found in vertebrates and invertebrates, though its structure varies across species. In humans, the pharynx is part of the digestive system and the conducting zone of the respiratory system. (The conducting zone—which also includes the nostrils of the nose, the larynx, trachea, bronchi, and bronchioles—filters, warms and moistens air and conducts it into the lungs.) The pharynx makes up the part of the throat"
"General Pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity and above the esophagus and larynx, or the tubes going down to the stomach and the lungs. It is found in vertebrates and invertebrates, though its structure varies across species. In humans, the pharynx is part of the digestive system and the conducting zone of the respiratory system. (The conducting zone—which also includes the nostrils of the nose, the larynx, trachea, bronchi, and bronchioles—filters, warms and moistens air and conducts it into the lungs.) The pharynx makes up the part of the"
"tube, but it is not recognized as a disorder in the ICD or DSM and its epidemiology is unknown. The most common types of tubes include those placed through the nose, including nasogastric, nasoduodenal, and nasojejunal tubes, and those placed directly into the abdomen, such as a gastrostomy, gastrojejunostomy, or jejunostomy feeding tube. A nasogastric feeding tube or NG-tube is passed through the nares (nostril), down the esophagus and into the stomach. This type of feeding tube is generally used for short term feeding, usually less than a month, though some infants and children may use an NG-tube longterm. Individuals"
"risk of opportunistic infection. In contrast, topical antibiotic eardrops can treat this condition. Tympanostomy tube Tympanostomy tube, also known as a grommet or myringotomy tube, is a small tube inserted into the eardrum in order to keep the middle ear aerated for a prolonged period of time, and to prevent the accumulation of fluid in the middle ear. The operation to insert the tube involves a myringotomy and is performed under local or general anesthesia. The tube itself is made in a variety of designs. The most commonly used type is shaped like a grommet. When it is necessary to"
"Ear canal The ear canal (external acoustic meatus, external auditory meatus, EAM; ) is a tube running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter. The human ear canal is divided into two parts. The elastic cartilage part forms the outer third of the canal; its anterior and lower wall are cartilaginous, whereas its superior and back wall are fibrous. The cartilage is the continuation of the cartilage framework of pinna. The bony part forms the inner two thirds. The"
"nasal cavity. When producing nasal consonants (such as ""m"", ""n"", and ""ng""), the soft palate remains relaxed, thereby enabling the air to go through the nose. The Eustachian tube, which opens near the velopharyngeal sphincter, connects the middle ear and nasal pharynx. Normally, the tube ensures aeration and drainage (of secretions) of the middle ear. Narrow and closed at rest, it opens during swallowing and yawning, controlled by the tensor veli palatini and the levator veli palatini (muscles of the soft palate). Children with a cleft palate have difficulties controlling these muscles and thus are unable to open the Eustachian"
"Trachea The trachea, colloquially called the windpipe, is a cartilaginous tube that connects the pharynx and larynx to the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. This is the only complete tracheal ring, the others being incomplete rings of reinforcing cartilage. The trachealis muscle joins the ends of the rings and these are joined vertically by bands of fibrous connective tissue – the"
"of the fauces. It works with the mouth, ears and nose, as well as a number of other parts of the body. Its pharynx is connected to the mouth, allowing speech to occur, and food and liquid to pass down the throat. It is joined to the nose by the nasopharynx at the top of the throat, and to ear by its Eustachian tube. The throat's trachea carries inhaled air to the bronchi of the lungs. The esophagus carries food through the throat to the stomach. Adenoids and tonsils help prevent infection and are composed of lymph tissue. The larynx"
"Nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes through the pharynx, shared with the digestive system, and then into the rest of the respiratory system. In humans, the nose is located centrally on the face and serves as an alternative respiratory passage especially during suckling for infants. On most other mammals, it is located on the upper tip of the snout. Acting as the first interface between"
"of mucous membrane called the philtrum, which runs from the tip of the nose to the mouth. The upper lip is constrained by this connection and has fewer nerves to control movement, which leaves it less mobile than the upper lips of simians. The philtrum creates a gap (diastema) between the roots of the first two upper incisors. The strepsirrhine rhinarium can collect relatively non-volatile, fluid-based chemicals (traditionally categorized as pheromones) and transmit them to the vomeronasal organ (VNO), which is located below and in front of the nasal cavity, above the mouth. The VNO is an encased duct-like structure"
"ear canals. It plays an important role in the human ear canal, assisting in cleaning and lubrication, and also provides some protection from bacteria, fungi, and insects. Excess or impacted cerumen can press against the eardrum and/or occlude the external auditory canal and impair hearing, causing conductive hearing loss. Ear canal The ear canal (external acoustic meatus, external auditory meatus, EAM; ) is a tube running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter. The human ear canal is divided"
"Nostril A nostril (or naris , plural ""nares"" ) is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation. Fish do not breathe through their noses, but they do have two small holes used for smelling, which may, indeed, be called nostrils. The Procellariiformes are distinguished from other birds by having tubular extensions of their nostrils. In humans, the nasal cycle is the normal ultradian cycle"
"Nasopharyngeal airway In medicine, a nasopharyngeal airway, also known as an NPA, nasal trumpet (because of its flared end), or nose hose, is a type of ""airway adjunct"", is a tube that is designed to be inserted into the nasal passageway to secure an open airway. When a patient becomes unconscious, the muscles in the jaw commonly relax and can allow the tongue to slide back and obstruct the airway. This makes airway management necessary, and an NPA is one of the available tools. The purpose of the flared end is to prevent the device from becoming lost inside the"
"on the patient: the device should reach from the patient's nostril to the earlobe or the angle of the jaw. The outside of the tube is lubricated with a water-based lubricant so that it enters the nose more easily. The device is inserted until the flared end rests against the nostril. Nasopharyngeal airway In medicine, a nasopharyngeal airway, also known as an NPA, nasal trumpet (because of its flared end), or nose hose, is a type of ""airway adjunct"", is a tube that is designed to be inserted into the nasal passageway to secure an open airway. When a patient"
"Perilymphatic duct In the anatomy of the human ear, the perilymphatic duct is where the perilymphatic space (vestibule of the ear) is connected to the subarachnoid space. This works as a type of shunt to eliminate excess perilymph fluid from the perilymphatic space around the cochlea of the ear. Perilymph is continuous with cerebrospinal fluid (CSF) in the subarachnoid space. CSF pressure abnormalities do not generally have clinical impact on the inner ear which is explained physically by the bore diameter and length of the perilymphatic duct. This duct goes through the skull and is parallel with but not directly"
"view the glottis). A tracheal tube is a catheter that is inserted into the trachea for the primary purpose of establishing and maintaining a patent (open and unobstructed) airway. Tracheal tubes are frequently used for airway management in the settings of general anesthesia, critical care, mechanical ventilation and emergency medicine. Many different types of tracheal tubes are available, suited for different specific applications. An endotracheal tube is a specific type of tracheal tube that is nearly always inserted through the mouth (orotracheal) or nose (nasotracheal). It is a breathing conduit designed to be placed into the airway of critically injured,"
"via the pharyngeal opening of the Eustachian tube. The inner ear contains the otolith organs—the utricle and saccule—and the semicircular canals belonging to the vestibular system, as well as the cochlea of the auditory system. The outer ear is the external portion of the ear and includes the fleshy visible pinna (also called the auricle), the ear canal, and the outer layer of the eardrum (also called the tympanic membrane). The pinna consists of the curving outer rim called the helix, the inner curved rim called the antihelix, and opens into the ear canal. The tragus protrudes and partially obscures"
"Nasolacrimal duct The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards. The opening of the nasolacrimal duct into the inferior nasal meatus of the nasal cavity is partially covered by a mucosal fold (valve of Hasner or ""plica lacrimalis""). Excess tears flow through nasolacrimal duct which drains into the inferior nasal meatus. This is the reason the nose starts to run when a person is crying or has"
"air inhaled. The trachea is the tube which carries air from the oral cavity and into the lungs, and is about 75–80 cm in length in the adult. It is held permanently open by 50-60 ""C""-shaped rings of cartilage, 5–6 cm in diameter. At the bifurcation of the trachea, there are two bronchi, the right of which is slightly larger in size. The bronchi then branch into smaller bronchioles, which in turn branch off into smaller bronchioles until they reach the alveoli (which absorb oxygen from the air and releases the carbon dioxide waste). The bronchi and bronchioles are all"
"Nose chain A nose chain is a type of facial jewellery that originated centuries ago as a part of women's fashion in India. Simply put, the nose chain is a link between a nose piercing and an ear piercing. Typically, these ""chains"" are just that: chain links, usually (though not always) made of some kind of metal. Yet, besides actual chains, the term """"nose chain"""" can denote other types of connecting materials between nose and ear piercings, such as the common alternative of rosary beads. Other connectors can be used as well. The nose chain has been commonly worn by"
"Nose chain A nose chain is a type of facial jewellery that originated centuries ago as a part of women's fashion in India. Simply put, the nose chain is a link between a nose piercing and an ear piercing. Typically, these ""chains"" are just that: chain links, usually (though not always) made of some kind of metal. Yet, besides actual chains, the term """"nose chain"""" can denote other types of connecting materials between nose and ear piercings, such as the common alternative of rosary beads. Other connectors can be used as well. The nose chain has been commonly worn by"
"the auditory tubes serves to equalize the barometric pressure in the middle ear with that of the ambient atmosphere. The anterior aspect of the nasopharynx communicates through the choanae with the nasal cavities. On its lateral wall is the pharyngeal opening of the auditory tube, somewhat triangular in shape, and bounded behind by a firm prominence, the torus tubarius or cushion, caused by the medial end of the cartilage of the tube which elevates the mucous membrane. Two folds arise from the cartilaginous opening: The oropharynx lies behind the oral cavity, extending from the uvula to the level of the"
"of the duct and is called a dacryocystocele or ""Timo cyst"". Persons with dry eye conditions can be fitted with punctal plugs that seal the ducts to limit the amount of fluid drainage and retain moisture. During an ear infection, excess mucus may drain through the nasolacrimal duct in the opposite way tears drain. The canal containing the nasolacrimal duct is called the nasolacrimal canal. In humans, the tear ducts in males tend to be larger than the ones in females. Nasolacrimal duct The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye"
"between the outer ear and the inner ear. It consists of an air-filled cavity called the tympanic cavity and includes the three ossicles and their attaching ligaments; the auditory tube; and the round and oval windows. The ossicles are three small bones that function together to receive, amplify, and transmit the sound from the eardrum to the inner ear. The ossicles are the malleus (hammer), incus (anvil), and the stapes (stirrup). The stapes is the smallest named bone in the body. The middle ear also connects to the upper throat at the nasopharynx via the pharyngeal opening of the Eustachian"
"simply referred to as intubation, is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs. The most widely used route is orotracheal, in which an endotracheal tube is passed through the mouth and vocal apparatus into the trachea. In a nasotracheal procedure, an endotracheal tube is passed through the nose and vocal apparatus into the trachea. Alternatives to standard endotracheal tubes include laryngeal tube and combitube. Surgical methods for airway management rely on making a surgical incision below the glottis"
"Tracheotomy Tracheotomy (, ), or tracheostomy, is a surgical procedure which consists of making an incision on the anterior aspect of the neck and opening a direct airway through an incision in the trachea (windpipe). The resulting stoma (hole) can serve independently as an airway or as a site for a tracheal tube or tracheostomy tube to be inserted; this tube allows a person to breathe without the use of the nose or mouth. The etymology of the word ""tracheotomy"" comes from two Greek words: the root ""tom-"" (from Greek τομή ""tomḗ"") meaning ""to cut"", and the word ""trachea"" (from"
"groove into a closed tube called the neural tube. The formation of the neural tube is called neurulation. At this stage, the walls of the neural tube contain proliferating neural stem cells in a region called the ventricular zone. The neural stem cells, principally radial glial cells, multiply and generate neurons through the process of neurogenesis, forming the rudiment of the central nervous system. The neural tube gives rise to both brain and spinal cord. The anterior (or 'rostral') portion of the neural tube initially differentiates into three brain vesicles (pockets): the prosencephalon at the front, the mesencephalon, and, between"
"the tube, while its base lies directly under the mucous membrane of the nasal part of the pharynx, where it forms an elevation, the torus tubarius or cushion, behind the pharyngeal opening of the auditory tube. The upper edge of the cartilage is curled upon itself, being bent laterally so as to present on transverse section the appearance of a hook; a groove or furrow is thus produced, which is open below and laterally, and this part of the canal is completed by fibrous membrane. The cartilage lies in a groove between the petrous part of the temporal bone and"