Search Encyclopedia The ear is the organ of hearing and balance. The parts of the ear include: External or outer ear, consisting of: Pinna or auricle. This is the outside part of the ear. External auditory canal or tube. This is the tube that connects the outer
ear to the inside or middle ear. Tympanic membrane (eardrum). The tympanic membrane divides the external ear from the middle ear. Middle ear (tympanic cavity), consisting of: Ossicles. Three small bones that are connected and transmit the sound waves to the inner ear. The bones are called: Malleus Incus Stapes Eustachian
tube. A canal that links the middle ear with the back of the nose. The eustachian tube helps to equalize the pressure in the middle ear. Equalized pressure is needed for the proper transfer of sound waves. The eustachian tube is lined with mucous, just like the inside of the nose and throat. Inner ear, consisting of: Cochlea. This contains the nerves for hearing. Vestibule.
This contains receptors for balance. Semicircular canals. This contains receptors for balance. Hearing starts with the outer ear. When a sound is made outside the outer ear, the sound waves, or vibrations, travel
down the external auditory canal and strike the eardrum (tympanic membrane). The eardrum vibrates. The vibrations are then passed to 3 tiny bones in the middle ear called the ossicles. The ossicles amplify the sound. They send the sound waves to the inner ear and into the fluid-filled hearing organ (cochlea). Once the sound waves reach the inner ear, they are converted into electrical impulses. The auditory nerve sends these impulses to the brain. The brain then translates these
electrical impulses as sound. Medical Reviewers: Author: Jana Vasković MD • Reviewer: Dimitrios Mytilinaios MD, PhD The ear is a complex part of an even more complex sensory system. It is situated bilaterally on the human skull, at the same level as the nose. The main functions of the ear are, of course, hearing, as well as constantly maintaining balance. The ear is anatomically divided into three portions:
This mixture of bones, nerves, vessels, membranes, and muscles that make up the ear will be described in this article. External earThe external ear, like the middle ear, serves only to conduct sound to the inner ear. It consists of the auricle and external acoustic meatus (or ear canal).
At the bottom of the ear canal is the tympanic membrane which establishes the border between the external and middle ear. AuricleThe auricle, also known as pinna, is a wrinkly musculocutaneous tissue that is attached to the skull and it functions to capture sound. The auricle is mostly made up of cartilage that is covered with skin. There are two aspects of the auricle: and medial (inner) and lateral (outer). The medial aspect of the ear lobe is attached to the skull and has no major practical significance. The lateral aspect is concave and presents numerous grooves and ridges. The outer rim of the auricle is called the helix, which then inferiorly ends as soft tissue known as the lobule of auricle (or ear lobe). The helix has three parts: crus, spine, and tail. The crus is the anterosuperior convex arch the helix, the spine the thick superior part of the helix, while the tail is continuous with the lobule. Parallel to the helix is another convex curvature referred to as the antihelix, which has two parts: the triangular fossa bound by the crus of the helix and the antihelix; and the crura of the antihelix which is the widening of the antihelix directed posteriorly toward the helix. Auricle (anterior view)The center of the auricle has a fossa that is continuous with the external acoustic meatus called the concha of the auricle. This concha is covered with a triangular cartilaginous process called the tragus. The base of the tragus is attached to facial skin, whereas its apex partially covers the entrance to the external acoustic meatus. Opposite to the tragus, there is also a cartilaginous elevation above the lobule called antitragus. External acoustic meatusThis is a bony-cartilaginous canal that projects from the auricle to the middle ear, from which it is separated by the tympanic membrane (eardrum). The external acoustic meatus consists of the lateral (outer) cartilaginous part, referred to as the cartilaginous or membranous external acoustic meatus, and the medial (inner) bony part, called the bony external acoustic meatus. Observed antero-posteriorly, this canal looks entirely like a broken line, meaning that it doesn’t follow a straight course. The lateral part of the canal is directed posteriorly and superiorly, whereas the medial part is directed anteriorly and inferiorly. This is important to know while examining the ear, because the auricle must be pulled backwards, upwards and slightly laterally in order for the lateral and medial portions to align, and so that the tympanic membrane can then be seen and examined properly. The membranous external acoustic meatus makes up the lateral one-third of this canal. Its anterior and inferior walls are made of cartilage because it is a continuation of the auricle. On the other hand the posterior and superior walls are actually fibrous membranes. The bony external acoustic meatus makes up the the medial two-thirds of the canal. Its anterior and inferior walls are built by the tympanic part of the temporal bone, whereas its posterior and superior walls are built by the squamous part of the temporal bone. Note that the posterior wall of the bony canal is anatomically related to the mastoid cells of the mastoid process, while the anterior and inferior walls are related to the temporomandibular joint. Tympanic membraneThe tympanic membrane, or simply the eardrum, is found at the bottom of the bony external acoustic meatus and it is the border between the external and middle ear. It is attached with a fibrocartilaginous ring to the tympanic part of the temporal bone. Based on its structure and tension, the tympanic membrane is divided into the two following parts:
It also has two sides: medial (inner) and lateral (outer). The medial side of the tympanic membrane is covered with mucosa and is entirely convexed towards the middle ear. On this side, around the border between the pars tensa and pars flaccida is the ridge of the chorda tympani, below which the chorda tympani nerve (branch of the facial nerve (CN VII)) passes. Also, the malleus bone is found on the medial side of the membrane and makes impressions on it. The lateral aspect of the tympanic membrane is divided into four quadrants: anterosuperior, anteroinferior, posterosuperior, and posteroinferior. Behind the two superior quadrants on the medial side are the auditory ossicles (stapes, malleus, and incus) and the chorda tympani. The attachment of the lower end and the handle of the malleus on the medial side of the tympanic membrane create the concavity on the lateral side that is called the umbo of the tympanic membrane. Superior to the umbo is a stripe called the malleolar stria which is the impression made by the rest of the handle of the malleus. The superior end of the malleolar stria presents with a ridge called the malleolar prominence. This impression is because of the lateral process of the malleus. The lateral side of the tympanic membrane is covered with skin and a thin layer of the cerumen. Muscles of the external earAll muscles of the external ear are associated with the auricle and are innervated by posterior auricular branches of the facial nerve (CN VII). They are classified into two groups, intrinsic and extrinsic. Intrinsic muscles contribute to defining the shape of the auricle by passing between its cartilaginous parts. They are: helicis major, helicis minor, tragus, pyramidal muscle of auricle, antitragus muscle, transverse muscle of auricle, and oblique muscle of auricle. Extrinsic muscles play a role in positioning the auricle, originating from the skull and attaching within the auricle itself. They are: auricularis anterior, auricularis superior, and auricularis posterior. Key facts about the extrinsic muscles of the external ear
A fun fact about the extrinsic muscles is that they are remnants from earlier evolution, and now we cannot consciously move them. To imagine how would it look like if we could, think of of a rabbit moving its ears around towards a sound! Practicing what you've learned is essential! Luckily, we've prepared these blank ear diagrams and quizzes just for you. Vasculature of the external earThree arteries participate in the supply of the auricle: the posterior auricular artery (branch of the external carotid artery), anterior auricular arteries (branches of the superficial temporal artery), and minor branches of the occipital artery. Veins that drain the auricle mirror the arteries, while the lymph is drained into the superficial parotid, mastoid, deep cervical, and superficial cervical lymph nodes. The tympanic membrane is vascularized by the branches of the maxillary artery (deep auricular, and anterior tympanic arteries), the stylomastoid artery (branch of the posterior auricular artery), and inferior tympanic artery (branch of the ascending pharyngeal artery). The lymph drains to the periauricular lymph nodes. Innervation of the external earThe sensory nerves that supply the auricle are numerous:
Most of the sensory innervation of the external acoustic meatus is by:
Because of vagus nerve innervation, any irritation of the external ear may cause a reflex cough. The lateral side of the tympanic membrane is innervated by the anterior auricular nerves (branches of the auriculotemporal nerve) and the auricular branch of the vagus nerve. On the other hand the medial side has its sensory innervation by the glossopharyngeal (IX) nerve. Middle earThe middle ear is a complex system of openings and canals placed mostly within the temporal bone. Its function is to transfer vibrations of the tympanic membrane into sound waves and pass them to the inner ear. The middle ear is made up of the tympanic cavity and epitympanic recess. The tympanic cavity is directly medial to the tympanic membrane, whereas the epitympanic recess is the space superior to the membrane. Anterior to the tympanic cavity is the pharyngotympanic tube (Eustachian tube) which extends to the pharynx, while posterior to the cavity are the mastoid cells of the mastoid process of the temporal bone. Mastoid cells are covered with mucosa that has extended from the nasopharynx through the pharyngotympanic tube and then through the tympanic cavity. Key facts about the middle ear
The anatomical communication between the pharynx, middle ear, and mastoid cells is a possible path of spreading infections. Test yourself on the structures of the middle ear with this quiz. Tympanic cavityThis is a bony-membranous cavity. It is shaped like a biconcave lens, but from an anatomical aspect it is usually described as a six-sided prism. Along with these six walls, the auditory ossicles can also be described within the anatomy of the tympanic cavity. Walls of the tympanic cavity
Let's discuss briefly the features of the labyrinthine wall.
The projection of the facial canal here is important, since the wall can sometimes contain openings and therefore infections of the middle ear can easily spread to the facial nerve and cause paralysis of its innervated structures. Auditory ossiclesThese are the three smallest bones of the human body. Their main function is to transmit sounds to the internal ear, precisely to the labyrinth within the internal ear. They articulate with each other with synovial joints, and transmit vibrations by being moved by the muscles of the middle ear. In order from the tympanic membrane to the internal ear (lateral to medial), these bones are:
A fun fact about these bones is that they lack osteogenic periosteum. MalleusThe malleus is laterally attached to the tympanic membrane and medially it articulates with the incus through the incudomalleolar joint. From the tympanic membrane it receives sound vibrations which it further transmits to the incus. It has several parts that include: head, neck, anterior and lateral processes, and the handle of the malleus. The head is placed within the epitympanic recess and it contains the articulation surface for the incus. It is connected to the tegmental wall of the tympanic cavity by the superior ligament of the malleus. Inferior to the head is the neck of the malleus, which contains two processes:
The extension that runs inferior to the neck and attaches to the central part of the tympanic membrane is the handle of the malleus. IncusThe incus is the anatomical connection of the malleus and stapes. It consists of three parts: the body and the long and short limbs.
StapesThe stapes articulates with the incus laterally through the incudostapedial joint, while medially it is attached to the membrane of the oval window on the labyrinthine wall of the tympanic cavity. The vibrations carried from the malleus through incus and to the stapes then cause the membrane on the oval window to vibrate further transmitting sound to the vestibule of the internal ear. The parts of the stapes are:
Muscles of the auditory ossiclesEven though the muscles related to the auditory ossicles are small, they are very important because their synergistic actions enable sound transmission. They also protect the internal ear from stimuli that are too strong by controlling the movements of the ossicles. These muscles are the tensor tympani muscle and the stapedius muscle. Key facts about the muscles of the auditory ossicles
The tensor tympani muscle is attached to the walls of the semicanal for tensor tympani on the medial side, and to the malleus on the lateral side. Its contraction pulls the malleus medially and in this way it tenses the tympanic membrane and pushes the stapes into the oval window. The stapedius muscle is placed within the pyramidal eminence of the mastoid wall of the tympanic cavity. It extends a very thin tendon that attaches to the incus. The stapedius pulls the incus laterally and therefore it pulls the stapes out of the oval window. Vasculature of the middle earThe arteries that supply the tympanic cavity are the following:
The tympanic veins drain deoxygenated blood into the superior petrosal sinus and the pterygoid venous plexus. Lymph drains into the retroauricular cervical lymph nodes. Innervation of the middle earWhen it comes to innervation, the mucosa that covers the walls of the middle ear is supplied with the tympanic nerve (branch of the glossopharyngeal nerve (CN IX)), whereas the muscles of the auditory ossicles are innervated by the tensor tympani nerve (tensor tympani muscle) and stapedius nerve (stapedius muscle). The tympanic nerve and caroticotympanic nerves of the internal carotid plexus form the tympanic plexus in the mucous membrane that covers the promontory on the labyrinthine wall. This plexus supplies the mucosa of the middle ear, pharyngotympanic tube, and mastoid antrum. It also gives off the lesser petrosal nerve, which provides parasympathetic innervation for the otic ganglion. Pharyngotympanic tubeThe pharyngotympanic (auditory) tube, commonly known as the Eustachian tube, connects the middle ear and the nasopharynx. The air pressure in the external ear and the nasopharynx is equal to atmospheric (open air) pressure, so this communication between the middle ear and the nasopharynx serves primarily to equalize pressure on both sides of the tympanic membrane. Equalization happens with the tube staying closed most of the time. The action of yawning or swallowing opens the tube, which allows air to flow and pressure to equalize. We’re sure that anytime you were driving up a mountain, you felt that change of pressure as if someone put plugs into your ears. If it wasn’t for the pharyngotympanic tube, the membrane would easily rupture very quickly under pressure. The opening of the pharyngotympanic tube is on the carotid (anterior) wall of the middle ear, from which the tube extends forward, medially, and downward on its way to nasopharynx. The one-third of the tube that is closer to the middle ear (posterolateral third) is the bony part, whereas the rest of the tube is the cartilaginous part. The tube is mostly vascularized by the ascending pharyngeal artery, which is a branch of the external carotid artery. The middle meningeal artery and the artery of the pterygoid canal (branches of the maxillary artery) also participate in blood supply of the pharyngotympanic tube. Venous blood drains into the pterygoid venous plexus, while lymph drains into the deep cervical lymph nodes. The mucosa that covers the tube is innervated by the tympanic plexus which is actually an indirect way for the tympanic nerve (a branch of the glossopharyngeal nerve (CN IX)) to supply the tube. Internal earThis is definitely the most complex part of the ear, so it’s not a coincidence that it is called the labyrinth. It is placed in the petrous part of the temporal bone and is made up of bony cavities in which specific membranous parts fit. For this reason, the internal ear is analyzed as the bony labyrinth and the membranous labyrinth which fits within the bony labyrinth. Note that the bony labyrinth is filled with the perilymph, whereas the membranous is filled with endolymph. This means that the membranous labyrinth is suspended in the perilymph of the bony labyrinth. Bony labyrinthThe bony labyrinth is placed in the petrous part of the temporal bone, and is separated from the middle ear by the labyrinthine (medial) wall of the tympanic cavity. Grossly, it is located medially and slightly posteriorly to the tympanic cavity. It contains the vestibulocochlear organ, presented with the spiral organ of Corti (the origin of the cochlear nerve which serves for hearing), and the vestibular nerve which provides the balance information. These two nerves are branches of the vestibulocochlear nerve (CN VIII). From its medial to lateral portion, the bony labyrinth contains the following structures:
All three of those are actually cavities that communicate with each other. Their main function is to house corresponding parts of the membranous labyrinth. VestibuleThe vestibule is a central bony cavity. It contains two sacs: the utricle and saccule of the vestibular labyrinth (part of the membranous labyrinth). The vestibule communicates with the tympanic membrane through the oval window on its lateral wall. Anteriorly it communicates with the cochlea, and postero-superiorly with the semicircular canals. The vestibule communicates with the posterior cranial fossa through the vestibular aqueduct. It is a membranous structure that leaves the vestibule, courses medially, passes through the temporal bone and opens on the posterior surface of the petrous part of the temporal bone. Semicircular canalsThese three canals are positioned postero-superiorly to the vestibule. The canals are placed in three different plans, where each canal makes an angle of 90 degrees with the other. Within the semicircular canal are the corresponding semicircular ducts of the membranous labyrinth. The anterior semicircular canal is positioned on the sagittal plane, the posterior is on the frontal plane, and the the lateral canal is placed horizontally on the transverse plane. Each canal ends in the form of a dilated ampulla, while the rest of the canal is narrow. Note that the anterior and posterior semicircular canals unite and form the common bony limb. CochleaCochlea is Greek for snail, and that’s exactly how this structure looks–a spiral and hollow bone chamber in which sound waves propagate from the base (near the oval window) to the apex. After the base of the cochlea is a tube, called spiral canal of the cochlea, that twists around a central bony column (called the modiolus) two and a half times. Inside the spiral canal of the cochlea is the osseous spiral lamina that is attached to the outer wall of modiolus and extends into the cochlear canal. In this way it follows the wrapping of the spiral canal around the modiolus. Since the spiral lamina is attached only to the modiolus, it incompletely divides the inner space of the spiral canal into the two canals:
These portions communicate with each other at the apex of the cochlea through a narrow slit called the helicotrema. Note that the scala vestibuli is continuous with the vestibule, whereas the scala tympani is placed in front of the round window on the labyrinthine (medial) wall of the middle ear–so it is separated from the middle ear by the secondary tympanic membrane which seals the round window. Similar to the vestibule, the cochlea communicates with the posterior cranial fossa through its own cochlear aqueduct. This canal emerges near the round window, passes through the temporal bone and opens on its posterior surface in the cranium. Membranous labyrinthThe membranous labyrinth is a system of membranous cavities filled with endolymph which are suspended in the perilymph of the bony labyrinth. The membranous structures found within the bony labyrinth are:
UtricleThe utricle is a sac which fills the postero-superior portion of the vestibule. On its superior and posterior walls it has openings that correspond to the openings of the vestibule and which are the place of the emerging of the semicircular ducts. The inner surface of the utricle is covered with sensory tissue for balance called the macula of the utricle. This tissue comprises of cells that are rich with cilia and otholites. The macula responds to both centrifugal and linear acceleration, and the nerve that conducts this information begins right at this spot and is called the utricular nerve (a branch of the utriculo-ampullary nerve). SacculeThe saccule is smaller than the utricle and it is placed in the antero-inferior part of the vestibule. Through the ductus reuniens, the cochlea is connected to the saccule, and in this way empties into the saccule. On the inner surface of the saccule is the sensory tissue called macula of the saccule that responds to linear acceleration. The information registered here transmits further through the saccular nerve that begins in this macula. The saccule extends a communicating duct with the utricle, called the utriculosaccular duct. From this duct the endolymphatic duct extends–it enters the vestibular aqueduct, passes through the temporal bone and ends as the endolymphatic sac at the posterior surface of the petrous part of the temporal bone. Semicircular ductsThe membranous semicircular ducts are suspended in the bony semicircular canals. The spatial relation here is important for the function, so let’s recall that the canals, as well as the ducts, are placed on three different planes, where each duct makes an angle of 90 degrees to the other. The anterior semicircular duct is positioned on the sagittal plane, the posterior semicircular duct is on the frontal plane, whereas the lateral semicircular duct is placed transversely. Each duct then opens to the saccule via a dilated end called the ampulla. Because of this arrangement, each duct responds to movements directed within the plane with which they are aligned. Cochlear labyrinthThe organ of hearing (spiral organ) is presented within the cochlear duct. This is a triangular shaped membranous duct that wraps around the modiolus two and a half times, following the quilling of both the spiral canal of the cochlea and the osseous spiral lamina. The cochlear duct completely follows the anatomy of the bony labyrinth, meaning it is also divided into two canals–scala vestibuli and scala tympani (previously described in the Cochlea section). The cochlear duct has three walls:
On the basilar membrane inside this duct is the spiral organ, which is the organ of hearing. This structure contains mechanoreceptors called hair cells. The tips of the cells project out of the spiral organ and into the endolymph of the cochlear duct. The hair cells are covered with the tectorial membrane, which moves during oscillations of the endolymph that happen each time a sound wave is transmitted. The movements of the tectorial membrane stimulate the hair cells which then generate electrical impulses that transmit through the cochlear nerve to the brain. Vasculature of the internal earThe bony labyrinth is vascularized by the anterior tympanic artery (a branch of the maxillary artery), stylomastoid artery (a branch of the posterior auricular artery), and the petrosal artery (a branch of the middle meningeal artery). On the other hand, the membranous labyrinth is supplied by the labyrinthine artery (a branch of the basilar artery). Venous blood is drained by the vestibular and cochlear veins. They merge and form the labyrinthine vein, which empties into the sigmoid or the inferior petrosal sinus. Lymphatic drainage is by the parotid, mastoid, and superficial cervical lymph nodes. Innervation of the internal earWhen it comes to innervation, the cochlear nerve carries sensory hearing information after arising from the spiral ganglion. It passes through the modiolus and the base of the cochlea. The vestibular nerve arises from the sensory tissues of the semicircular ducts, utricle, and saccule carries sensory balance information. It forms the vestibular ganglion which provides superior and inferior branches, which again, split and provide the branches: utriculo-ampullary nerve, saccular nerve, and posterior ampullary nerve. Then, the utriculo-ampullary nerve splits again into the utricular, anterior ampullary, and lateral ampullary nerve. The cochlear and vestibular nerves unite and form the vestibulocochlear nerve (CN VIII), which exits through the internal acoustic meatus together with the facial nerve (CN VII) and travels to the lateral surface of the brainstem. Learn more about the anatomy of the inner ear in our comprehensive study units: Transmission of soundAt the external ear, sound waves captured by the auricle enter the external acoustic meatus, and travel through it to the tympanic membrane. Under the strike of the wave, the membrane moves medially, affecting the handle of the malleus attached to the medial surface of the tympanic membrane. In the middle ear, the handle of the malleus moves medially, so that its head moves laterally. Since the head of the malleus articulates with the body of the incus, the incus is also moved laterally, which pushes the long process of incus medially. Since the long process articulates with the stapes, this will push the stapes medially, and cause its base to hit the oval window which then moves medially as well. This will cause a large amplitude wave of the low force to be transformed into a small amplitude vibration of a high force in the internal ear. This then vibrates the fluid inside the scala vestibuli of the cochlea. The receptors then send the information via the cochlear part of the vestibulocochlear nerve (CN VIII) to the brain, where they will be interpreted as a sound via the auditory pathway. Transmission of balanceThe membranous semicircular ducts, utricle and saccule are responsible for maintaining balance. Note that the semicircular ducts detect movement of the head, while the saccule and utricle provide head position information when it is not moving. The anterior semicircular duct is positioned on the sagittal plane, the posterior semicircular duct is on the frontal plane, whereas the lateral semicircular duct is placed transversely. Because of this arrangement, each duct responds to movements directed within the plane with which they are aligned. The saccule detects accelerations and head tilts in the vertical plane, and the utricle detects accelerations and head tilts in the horizontal plane. The semicircular ducts, utricle, and saccule are filled with endolymph and contain motion receptors (hair cells). As the head rotates or tilts, the endolymph lags in the opposite direction due to inertia. This stimulates the stereocilia of the hair cells which generate an electric signal that is transmitted in the following way:
The utricular, anterior ampullary, and lateral ampullary nerves form utriculo-ampullary nerve. Then, the utriculo-ampullary nerve, saccular nerve and posterior ampullary nerve synapse within the vestibular ganglion. The vestibular nerve emerges from the vestibular ganglion, joins the cochlear nerve, and via the vestibulocochlear nerve carries sensory balance information to the central nervous system. Ear anatomy will be a lot easier to absorb after you take this specially designed quiz that covers all you need to know about the ear! Clinical relationsOtoscopic examinationThis procedure provides an examination of the external ear and the tympanic membrane. Because of the natural curvature of the external acoustic meatus, the physician needs to pull the helix of the auricle posterosuperiorly, in order to align the meatus in a straight direction. This enables proper placement of the otoscope. Normally, the tympanic membrane is shown as translucent and grey coloured. The handle of the malleus can be seen in the central part of the tympanic membrane. The inferior end of the handle reflects the cone of light directed anteroinferiorly. Auricular hematomaAuricular hematoma is a subcutaneous collection of blood that can appear after the bleeding within the auricle. The mass of the hematoma can compromise the vascularization of the auricle. Impacted cerumenCerumen (ear wax) is normally produced in the external ear. But when the cerumen builds up (impacts) in the external acoustic meatus, it can lead to its blockade and temporary hearing loss. It is treated by softening the earwax and removing it mechanically. InflammationsInflammations of the external and middle ear, called otitis can cause the damage of the tympanic membrane which may result with the hearing loss. Swelling of the mucosa of the pharyngotympanic (Eustachian) tube may lead to its occlusion. This eventually leads to a lowering of pressure within the tympanic cavity, retraction of the tympanic membrane, and its inability to move resulting in hearing impairment. DeafnessChronic exposure to loud sounds may result with degeneration of the spiral organ which leads to the high tone deafness. It is also called the sensorineural hearing loss. It is usually managed by cochlear implants which amplify sounds coming from the environment to enhance hearing ability. Motion sicknessThis state is caused by the sensory conflict between the vestibulocochlear and visual systems. In daily life, it happens while traveling by bus, plane, or boat. If you are sitting in the car, your vestibular system detects that the body is still and not moving. But at the same time, by looking through the window, you will see that you are moving. This conflict between the two systems systems stimulates the area postrema (the emetic center in the brain) and presents as the nausea or even vomiting. VertigoSimply speaking, vertigo is dizziness. It is usually a symptom of internal ear damage, such as infections, head or neck injuries, or tumors.
Since vertigo is a symptom, and not a disease, its treatment depends on discovering its cause and treating it. SourcesAll content published on Kenhub is reviewed by medical and anatomy experts. The information we provide is grounded on academic literature and peer-reviewed research. Kenhub does not provide medical advice. You can learn more about our content creation and review standards by reading our content quality guidelines. References:
Ear: want to learn more about it? Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster. What do you prefer to learn with? “I would honestly say that Kenhub cut my study time in half.” – Read more. Kim Bengochea, Regis University, Denver © Unless stated otherwise, all content, including illustrations are exclusive property of Kenhub GmbH, and are protected by German and international copyright laws. All rights reserved.What is the primary function of the outer ear multiple choice question?The Outer Ear
It collects sound waves and channels them into the ear canal (external auditory meatus), where the sound is amplified. The sound waves then travel toward a flexible, oval membrane at the end of the ear canal called the eardrum, or tympanic membrane. Sound waves cause the eardrum to vibrate.
Which of the following is located between the external and middle ear quizlet?The tympanic membrane, or eardrum, forms the boundary between the outer and middle ears.
Which cranial bone contains the bony labyrinth multiple choice question?The bony labyrinth, a cavity in the temporal bone, is divided into three sections: the vestibule, the semicircular canals, and the cochlea.
What is the name for the short tunnel that runs from the pinna to the eardrum?The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about 2.5 centimetres (1 in) in length and 0.7 centimetres (0.3 in) in diameter.
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